| Message ID | 1427079771-18472-1-git-send-email-gwshan@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Mon, 2015-03-23 at 14:02 +1100, Gavin Shan wrote: > The patch adds one more parameter ("probe") to pci_set_pcie_reset_state(), > which allows to check if one particular PCI device can be resetted by the > function. The function will be reused to support PCI device specific methods > maintained in pci_dev_reset_methods[] in subsequent patch. > > Cc: Brian King <brking@us.ibm.com> > Cc: Frank Haverkamp <haver@linux.vnet.ibm.com> > Cc: Ian Munsie <imunsie@au1.ibm.com> > Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> > --- > v3: Fix arguments of pci_set_pcie_reset_state() in cxl driver > v2: Reimplemented based on pci_set_pcie_reset_state() > --- > arch/powerpc/kernel/eeh.c | 14 ++++++++++---- > drivers/misc/cxl/pci.c | 2 +- > drivers/misc/genwqe/card_base.c | 9 +++++++-- > drivers/pci/pci.c | 15 +++++++++------ > drivers/scsi/ipr.c | 5 +++-- > include/linux/pci.h | 5 +++-- > 6 files changed, 33 insertions(+), 17 deletions(-) Argh, you're trying to make pci_set_pcie_reset_state() compatible with pci_dev_specific_reset(), so it can be called via pci_reset_function(), but the whole point of the pci_reset_function() interface is to reset a *single* function without disturbing anything else. These patches make no effort at all to limit the set of affected devices to a single function and take great liberties using PCI_ANY_ID for vendors. My take on the powerpc version of pcibios_set_pcie_reset_state() is that it's effectively a slot reset, so why not hook into the pci_reset_hotplug_slot() via the hotplug slot ops? Please also use cover letters. Thanks, Alex > diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c > index daa68a1..cd85c18 100644 > --- a/arch/powerpc/kernel/eeh.c > +++ b/arch/powerpc/kernel/eeh.c > @@ -726,11 +726,14 @@ static void *eeh_restore_dev_state(void *data, void *userdata) > * pcibios_set_pcie_slot_reset - Set PCI-E reset state > * @dev: pci device struct > * @state: reset state to enter > + * @probe: check if the device can take the reset > * > * Return value: > * 0 if success > */ > -int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) > +int pcibios_set_pcie_reset_state(struct pci_dev *dev, > + enum pcie_reset_state state, > + int probe) > { > struct eeh_dev *edev = pci_dev_to_eeh_dev(dev); > struct eeh_pe *pe = eeh_dev_to_pe(edev); > @@ -738,9 +741,12 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat > if (!pe) { > pr_err("%s: No PE found on PCI device %s\n", > __func__, pci_name(dev)); > - return -EINVAL; > + return -ENOTTY; > } > > + if (probe) > + return 0; > + > switch (state) { > case pcie_deassert_reset: > eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); > @@ -762,8 +768,8 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat > break; > default: > eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED); > - return -EINVAL; > - }; > + return -ENOTTY; > + } > > return 0; > } > diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c > index 1ef0164..3a87bfc 100644 > --- a/drivers/misc/cxl/pci.c > +++ b/drivers/misc/cxl/pci.c > @@ -789,7 +789,7 @@ int cxl_reset(struct cxl *adapter) > /* pcie_warm_reset requests a fundamental pci reset which includes a > * PERST assert/deassert. PERST triggers a loading of the image > * if "user" or "factory" is selected in sysfs */ > - if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset))) { > + if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset, 0))) { > dev_err(&dev->dev, "cxl: pcie_warm_reset failed\n"); > return rc; > } > diff --git a/drivers/misc/genwqe/card_base.c b/drivers/misc/genwqe/card_base.c > index 4cf8f82..4871f69 100644 > --- a/drivers/misc/genwqe/card_base.c > +++ b/drivers/misc/genwqe/card_base.c > @@ -782,17 +782,22 @@ static int genwqe_pci_fundamental_reset(struct pci_dev *pci_dev) > { > int rc; > > + /* Probe if the device can take the reset */ > + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 1); > + if (rc) > + return rc; > + > /* > * lock pci config space access from userspace, > * save state and issue PCIe fundamental reset > */ > pci_cfg_access_lock(pci_dev); > pci_save_state(pci_dev); > - rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset); > + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 0); > if (!rc) { > /* keep PCIe reset asserted for 250ms */ > msleep(250); > - pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset); > + pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset, 0); > /* Wait for 2s to reload flash and train the link */ > msleep(2000); > } > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 81f06e8..8581a5f 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -1558,28 +1558,31 @@ EXPORT_SYMBOL(pci_disable_device); > * pcibios_set_pcie_reset_state - set reset state for device dev > * @dev: the PCIe device reset > * @state: Reset state to enter into > - * > + * @probe: Check if the device can take the reset > * > * Sets the PCIe reset state for the device. This is the default > * implementation. Architecture implementations can override this. > */ > int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev, > - enum pcie_reset_state state) > + enum pcie_reset_state state, > + int probe) > { > - return -EINVAL; > + return -ENOTTY; > } > > /** > * pci_set_pcie_reset_state - set reset state for device dev > * @dev: the PCIe device reset > * @state: Reset state to enter into > - * > + * @probe: Check if the device can take the reset > * > * Sets the PCI reset state for the device. > */ > -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) > +int pci_set_pcie_reset_state(struct pci_dev *dev, > + enum pcie_reset_state state, > + int probe) > { > - return pcibios_set_pcie_reset_state(dev, state); > + return pcibios_set_pcie_reset_state(dev, state, probe); > } > EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state); > > diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c > index 9219953..89026f4 100644 > --- a/drivers/scsi/ipr.c > +++ b/drivers/scsi/ipr.c > @@ -8317,7 +8317,8 @@ static int ipr_reset_start_bist(struct ipr_cmnd *ipr_cmd) > static int ipr_reset_slot_reset_done(struct ipr_cmnd *ipr_cmd) > { > ENTER; > - pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, pcie_deassert_reset); > + pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, > + pcie_deassert_reset, 0); > ipr_cmd->job_step = ipr_reset_bist_done; > ipr_reset_start_timer(ipr_cmd, IPR_WAIT_FOR_BIST_TIMEOUT); > LEAVE; > @@ -8339,7 +8340,7 @@ static int ipr_reset_slot_reset(struct ipr_cmnd *ipr_cmd) > struct pci_dev *pdev = ioa_cfg->pdev; > > ENTER; > - pci_set_pcie_reset_state(pdev, pcie_warm_reset); > + pci_set_pcie_reset_state(pdev, pcie_warm_reset, 0); > ipr_cmd->job_step = ipr_reset_slot_reset_done; > ipr_reset_start_timer(ipr_cmd, IPR_PCI_RESET_TIMEOUT); > LEAVE; > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 4e1f17d..052ac63 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -960,7 +960,8 @@ extern unsigned int pcibios_max_latency; > void pci_set_master(struct pci_dev *dev); > void pci_clear_master(struct pci_dev *dev); > > -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state); > +int pci_set_pcie_reset_state(struct pci_dev *dev, > + enum pcie_reset_state state, int probe); > int pci_set_cacheline_size(struct pci_dev *dev); > #define HAVE_PCI_SET_MWI > int __must_check pci_set_mwi(struct pci_dev *dev); > @@ -1648,7 +1649,7 @@ extern unsigned long pci_hotplug_mem_size; > void pcibios_disable_device(struct pci_dev *dev); > void pcibios_set_master(struct pci_dev *dev); > int pcibios_set_pcie_reset_state(struct pci_dev *dev, > - enum pcie_reset_state state); > + enum pcie_reset_state state, int probe); > int pcibios_add_device(struct pci_dev *dev); > void pcibios_release_device(struct pci_dev *dev); > void pcibios_penalize_isa_irq(int irq, int active); -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sun, Mar 22, 2015 at 09:34:33PM -0600, Alex Williamson wrote: >On Mon, 2015-03-23 at 14:02 +1100, Gavin Shan wrote: >> The patch adds one more parameter ("probe") to pci_set_pcie_reset_state(), >> which allows to check if one particular PCI device can be resetted by the >> function. The function will be reused to support PCI device specific methods >> maintained in pci_dev_reset_methods[] in subsequent patch. >> >> Cc: Brian King <brking@us.ibm.com> >> Cc: Frank Haverkamp <haver@linux.vnet.ibm.com> >> Cc: Ian Munsie <imunsie@au1.ibm.com> >> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> >> --- >> v3: Fix arguments of pci_set_pcie_reset_state() in cxl driver >> v2: Reimplemented based on pci_set_pcie_reset_state() >> --- >> arch/powerpc/kernel/eeh.c | 14 ++++++++++---- >> drivers/misc/cxl/pci.c | 2 +- >> drivers/misc/genwqe/card_base.c | 9 +++++++-- >> drivers/pci/pci.c | 15 +++++++++------ >> drivers/scsi/ipr.c | 5 +++-- >> include/linux/pci.h | 5 +++-- >> 6 files changed, 33 insertions(+), 17 deletions(-) > > >Argh, you're trying to make pci_set_pcie_reset_state() compatible with >pci_dev_specific_reset(), so it can be called via pci_reset_function(), >but the whole point of the pci_reset_function() interface is to reset a >*single* function without disturbing anything else. These patches make >no effort at all to limit the set of affected devices to a single >function and take great liberties using PCI_ANY_ID for vendors. My take >on the powerpc version of pcibios_set_pcie_reset_state() is that it's >effectively a slot reset, so why not hook into the >pci_reset_hotplug_slot() via the hotplug slot ops? Please also use >cover letters. Thanks, > Yep, that's the point and intention of the patches. pcibios_set_pcie_reset_state() isn't equal to pci_reset_hotplug_slot(). The later one depends on PCI slot, which wasn't populated on PowerNV platform yet, but pcibios_set_pcie_reseet_state() doesn't. The patchset depends on improved pcibios_set_pcie_reset_state(), which can be seen from following linked. With it, we don't affect any PCI devices as the config space is saved/restored accordingly before/after reset: https://patchwork.ozlabs.org/patch/438598/ Sorry that I didn't use cover letter again. I'll have one next time always. Thanks, Gavin >Alex > >> diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c >> index daa68a1..cd85c18 100644 >> --- a/arch/powerpc/kernel/eeh.c >> +++ b/arch/powerpc/kernel/eeh.c >> @@ -726,11 +726,14 @@ static void *eeh_restore_dev_state(void *data, void *userdata) >> * pcibios_set_pcie_slot_reset - Set PCI-E reset state >> * @dev: pci device struct >> * @state: reset state to enter >> + * @probe: check if the device can take the reset >> * >> * Return value: >> * 0 if success >> */ >> -int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) >> +int pcibios_set_pcie_reset_state(struct pci_dev *dev, >> + enum pcie_reset_state state, >> + int probe) >> { >> struct eeh_dev *edev = pci_dev_to_eeh_dev(dev); >> struct eeh_pe *pe = eeh_dev_to_pe(edev); >> @@ -738,9 +741,12 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat >> if (!pe) { >> pr_err("%s: No PE found on PCI device %s\n", >> __func__, pci_name(dev)); >> - return -EINVAL; >> + return -ENOTTY; >> } >> >> + if (probe) >> + return 0; >> + >> switch (state) { >> case pcie_deassert_reset: >> eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); >> @@ -762,8 +768,8 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat >> break; >> default: >> eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED); >> - return -EINVAL; >> - }; >> + return -ENOTTY; >> + } >> >> return 0; >> } >> diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c >> index 1ef0164..3a87bfc 100644 >> --- a/drivers/misc/cxl/pci.c >> +++ b/drivers/misc/cxl/pci.c >> @@ -789,7 +789,7 @@ int cxl_reset(struct cxl *adapter) >> /* pcie_warm_reset requests a fundamental pci reset which includes a >> * PERST assert/deassert. PERST triggers a loading of the image >> * if "user" or "factory" is selected in sysfs */ >> - if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset))) { >> + if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset, 0))) { >> dev_err(&dev->dev, "cxl: pcie_warm_reset failed\n"); >> return rc; >> } >> diff --git a/drivers/misc/genwqe/card_base.c b/drivers/misc/genwqe/card_base.c >> index 4cf8f82..4871f69 100644 >> --- a/drivers/misc/genwqe/card_base.c >> +++ b/drivers/misc/genwqe/card_base.c >> @@ -782,17 +782,22 @@ static int genwqe_pci_fundamental_reset(struct pci_dev *pci_dev) >> { >> int rc; >> >> + /* Probe if the device can take the reset */ >> + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 1); >> + if (rc) >> + return rc; >> + >> /* >> * lock pci config space access from userspace, >> * save state and issue PCIe fundamental reset >> */ >> pci_cfg_access_lock(pci_dev); >> pci_save_state(pci_dev); >> - rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset); >> + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 0); >> if (!rc) { >> /* keep PCIe reset asserted for 250ms */ >> msleep(250); >> - pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset); >> + pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset, 0); >> /* Wait for 2s to reload flash and train the link */ >> msleep(2000); >> } >> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c >> index 81f06e8..8581a5f 100644 >> --- a/drivers/pci/pci.c >> +++ b/drivers/pci/pci.c >> @@ -1558,28 +1558,31 @@ EXPORT_SYMBOL(pci_disable_device); >> * pcibios_set_pcie_reset_state - set reset state for device dev >> * @dev: the PCIe device reset >> * @state: Reset state to enter into >> - * >> + * @probe: Check if the device can take the reset >> * >> * Sets the PCIe reset state for the device. This is the default >> * implementation. Architecture implementations can override this. >> */ >> int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev, >> - enum pcie_reset_state state) >> + enum pcie_reset_state state, >> + int probe) >> { >> - return -EINVAL; >> + return -ENOTTY; >> } >> >> /** >> * pci_set_pcie_reset_state - set reset state for device dev >> * @dev: the PCIe device reset >> * @state: Reset state to enter into >> - * >> + * @probe: Check if the device can take the reset >> * >> * Sets the PCI reset state for the device. >> */ >> -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) >> +int pci_set_pcie_reset_state(struct pci_dev *dev, >> + enum pcie_reset_state state, >> + int probe) >> { >> - return pcibios_set_pcie_reset_state(dev, state); >> + return pcibios_set_pcie_reset_state(dev, state, probe); >> } >> EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state); >> >> diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c >> index 9219953..89026f4 100644 >> --- a/drivers/scsi/ipr.c >> +++ b/drivers/scsi/ipr.c >> @@ -8317,7 +8317,8 @@ static int ipr_reset_start_bist(struct ipr_cmnd *ipr_cmd) >> static int ipr_reset_slot_reset_done(struct ipr_cmnd *ipr_cmd) >> { >> ENTER; >> - pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, pcie_deassert_reset); >> + pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, >> + pcie_deassert_reset, 0); >> ipr_cmd->job_step = ipr_reset_bist_done; >> ipr_reset_start_timer(ipr_cmd, IPR_WAIT_FOR_BIST_TIMEOUT); >> LEAVE; >> @@ -8339,7 +8340,7 @@ static int ipr_reset_slot_reset(struct ipr_cmnd *ipr_cmd) >> struct pci_dev *pdev = ioa_cfg->pdev; >> >> ENTER; >> - pci_set_pcie_reset_state(pdev, pcie_warm_reset); >> + pci_set_pcie_reset_state(pdev, pcie_warm_reset, 0); >> ipr_cmd->job_step = ipr_reset_slot_reset_done; >> ipr_reset_start_timer(ipr_cmd, IPR_PCI_RESET_TIMEOUT); >> LEAVE; >> diff --git a/include/linux/pci.h b/include/linux/pci.h >> index 4e1f17d..052ac63 100644 >> --- a/include/linux/pci.h >> +++ b/include/linux/pci.h >> @@ -960,7 +960,8 @@ extern unsigned int pcibios_max_latency; >> void pci_set_master(struct pci_dev *dev); >> void pci_clear_master(struct pci_dev *dev); >> >> -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state); >> +int pci_set_pcie_reset_state(struct pci_dev *dev, >> + enum pcie_reset_state state, int probe); >> int pci_set_cacheline_size(struct pci_dev *dev); >> #define HAVE_PCI_SET_MWI >> int __must_check pci_set_mwi(struct pci_dev *dev); >> @@ -1648,7 +1649,7 @@ extern unsigned long pci_hotplug_mem_size; >> void pcibios_disable_device(struct pci_dev *dev); >> void pcibios_set_master(struct pci_dev *dev); >> int pcibios_set_pcie_reset_state(struct pci_dev *dev, >> - enum pcie_reset_state state); >> + enum pcie_reset_state state, int probe); >> int pcibios_add_device(struct pci_dev *dev); >> void pcibios_release_device(struct pci_dev *dev); >> void pcibios_penalize_isa_irq(int irq, int active); > > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 2015-03-23 at 14:56 +1100, Gavin Shan wrote: > On Sun, Mar 22, 2015 at 09:34:33PM -0600, Alex Williamson wrote: > >On Mon, 2015-03-23 at 14:02 +1100, Gavin Shan wrote: > >> The patch adds one more parameter ("probe") to pci_set_pcie_reset_state(), > >> which allows to check if one particular PCI device can be resetted by the > >> function. The function will be reused to support PCI device specific methods > >> maintained in pci_dev_reset_methods[] in subsequent patch. > >> > >> Cc: Brian King <brking@us.ibm.com> > >> Cc: Frank Haverkamp <haver@linux.vnet.ibm.com> > >> Cc: Ian Munsie <imunsie@au1.ibm.com> > >> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> > >> --- > >> v3: Fix arguments of pci_set_pcie_reset_state() in cxl driver > >> v2: Reimplemented based on pci_set_pcie_reset_state() > >> --- > >> arch/powerpc/kernel/eeh.c | 14 ++++++++++---- > >> drivers/misc/cxl/pci.c | 2 +- > >> drivers/misc/genwqe/card_base.c | 9 +++++++-- > >> drivers/pci/pci.c | 15 +++++++++------ > >> drivers/scsi/ipr.c | 5 +++-- > >> include/linux/pci.h | 5 +++-- > >> 6 files changed, 33 insertions(+), 17 deletions(-) > > > > > >Argh, you're trying to make pci_set_pcie_reset_state() compatible with > >pci_dev_specific_reset(), so it can be called via pci_reset_function(), > >but the whole point of the pci_reset_function() interface is to reset a > >*single* function without disturbing anything else. These patches make > >no effort at all to limit the set of affected devices to a single > >function and take great liberties using PCI_ANY_ID for vendors. My take > >on the powerpc version of pcibios_set_pcie_reset_state() is that it's > >effectively a slot reset, so why not hook into the > >pci_reset_hotplug_slot() via the hotplug slot ops? Please also use > >cover letters. Thanks, > > > > Yep, that's the point and intention of the patches. pcibios_set_pcie_reset_state() > isn't equal to pci_reset_hotplug_slot(). The later one depends on PCI slot, which > wasn't populated on PowerNV platform yet, but pcibios_set_pcie_reseet_state() doesn't. > > The patchset depends on improved pcibios_set_pcie_reset_state(), which can be seen > from following linked. With it, we don't affect any PCI devices as the config space > is saved/restored accordingly before/after reset: > > https://patchwork.ozlabs.org/patch/438598/ Sorry, that's wrong. pci_reset_function() can be called while other devices in the same multifunction package are actively in use. It doesn't matter that you're saving and restoring the external state of the device, the internal state is lost and operation of the device is interrupted. That is not how pci_reset_function() is supposed to work. Thanks, Alex > >> diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c > >> index daa68a1..cd85c18 100644 > >> --- a/arch/powerpc/kernel/eeh.c > >> +++ b/arch/powerpc/kernel/eeh.c > >> @@ -726,11 +726,14 @@ static void *eeh_restore_dev_state(void *data, void *userdata) > >> * pcibios_set_pcie_slot_reset - Set PCI-E reset state > >> * @dev: pci device struct > >> * @state: reset state to enter > >> + * @probe: check if the device can take the reset > >> * > >> * Return value: > >> * 0 if success > >> */ > >> -int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) > >> +int pcibios_set_pcie_reset_state(struct pci_dev *dev, > >> + enum pcie_reset_state state, > >> + int probe) > >> { > >> struct eeh_dev *edev = pci_dev_to_eeh_dev(dev); > >> struct eeh_pe *pe = eeh_dev_to_pe(edev); > >> @@ -738,9 +741,12 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat > >> if (!pe) { > >> pr_err("%s: No PE found on PCI device %s\n", > >> __func__, pci_name(dev)); > >> - return -EINVAL; > >> + return -ENOTTY; > >> } > >> > >> + if (probe) > >> + return 0; > >> + > >> switch (state) { > >> case pcie_deassert_reset: > >> eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); > >> @@ -762,8 +768,8 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat > >> break; > >> default: > >> eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED); > >> - return -EINVAL; > >> - }; > >> + return -ENOTTY; > >> + } > >> > >> return 0; > >> } > >> diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c > >> index 1ef0164..3a87bfc 100644 > >> --- a/drivers/misc/cxl/pci.c > >> +++ b/drivers/misc/cxl/pci.c > >> @@ -789,7 +789,7 @@ int cxl_reset(struct cxl *adapter) > >> /* pcie_warm_reset requests a fundamental pci reset which includes a > >> * PERST assert/deassert. PERST triggers a loading of the image > >> * if "user" or "factory" is selected in sysfs */ > >> - if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset))) { > >> + if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset, 0))) { > >> dev_err(&dev->dev, "cxl: pcie_warm_reset failed\n"); > >> return rc; > >> } > >> diff --git a/drivers/misc/genwqe/card_base.c b/drivers/misc/genwqe/card_base.c > >> index 4cf8f82..4871f69 100644 > >> --- a/drivers/misc/genwqe/card_base.c > >> +++ b/drivers/misc/genwqe/card_base.c > >> @@ -782,17 +782,22 @@ static int genwqe_pci_fundamental_reset(struct pci_dev *pci_dev) > >> { > >> int rc; > >> > >> + /* Probe if the device can take the reset */ > >> + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 1); > >> + if (rc) > >> + return rc; > >> + > >> /* > >> * lock pci config space access from userspace, > >> * save state and issue PCIe fundamental reset > >> */ > >> pci_cfg_access_lock(pci_dev); > >> pci_save_state(pci_dev); > >> - rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset); > >> + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 0); > >> if (!rc) { > >> /* keep PCIe reset asserted for 250ms */ > >> msleep(250); > >> - pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset); > >> + pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset, 0); > >> /* Wait for 2s to reload flash and train the link */ > >> msleep(2000); > >> } > >> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > >> index 81f06e8..8581a5f 100644 > >> --- a/drivers/pci/pci.c > >> +++ b/drivers/pci/pci.c > >> @@ -1558,28 +1558,31 @@ EXPORT_SYMBOL(pci_disable_device); > >> * pcibios_set_pcie_reset_state - set reset state for device dev > >> * @dev: the PCIe device reset > >> * @state: Reset state to enter into > >> - * > >> + * @probe: Check if the device can take the reset > >> * > >> * Sets the PCIe reset state for the device. This is the default > >> * implementation. Architecture implementations can override this. > >> */ > >> int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev, > >> - enum pcie_reset_state state) > >> + enum pcie_reset_state state, > >> + int probe) > >> { > >> - return -EINVAL; > >> + return -ENOTTY; > >> } > >> > >> /** > >> * pci_set_pcie_reset_state - set reset state for device dev > >> * @dev: the PCIe device reset > >> * @state: Reset state to enter into > >> - * > >> + * @probe: Check if the device can take the reset > >> * > >> * Sets the PCI reset state for the device. > >> */ > >> -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) > >> +int pci_set_pcie_reset_state(struct pci_dev *dev, > >> + enum pcie_reset_state state, > >> + int probe) > >> { > >> - return pcibios_set_pcie_reset_state(dev, state); > >> + return pcibios_set_pcie_reset_state(dev, state, probe); > >> } > >> EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state); > >> > >> diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c > >> index 9219953..89026f4 100644 > >> --- a/drivers/scsi/ipr.c > >> +++ b/drivers/scsi/ipr.c > >> @@ -8317,7 +8317,8 @@ static int ipr_reset_start_bist(struct ipr_cmnd *ipr_cmd) > >> static int ipr_reset_slot_reset_done(struct ipr_cmnd *ipr_cmd) > >> { > >> ENTER; > >> - pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, pcie_deassert_reset); > >> + pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, > >> + pcie_deassert_reset, 0); > >> ipr_cmd->job_step = ipr_reset_bist_done; > >> ipr_reset_start_timer(ipr_cmd, IPR_WAIT_FOR_BIST_TIMEOUT); > >> LEAVE; > >> @@ -8339,7 +8340,7 @@ static int ipr_reset_slot_reset(struct ipr_cmnd *ipr_cmd) > >> struct pci_dev *pdev = ioa_cfg->pdev; > >> > >> ENTER; > >> - pci_set_pcie_reset_state(pdev, pcie_warm_reset); > >> + pci_set_pcie_reset_state(pdev, pcie_warm_reset, 0); > >> ipr_cmd->job_step = ipr_reset_slot_reset_done; > >> ipr_reset_start_timer(ipr_cmd, IPR_PCI_RESET_TIMEOUT); > >> LEAVE; > >> diff --git a/include/linux/pci.h b/include/linux/pci.h > >> index 4e1f17d..052ac63 100644 > >> --- a/include/linux/pci.h > >> +++ b/include/linux/pci.h > >> @@ -960,7 +960,8 @@ extern unsigned int pcibios_max_latency; > >> void pci_set_master(struct pci_dev *dev); > >> void pci_clear_master(struct pci_dev *dev); > >> > >> -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state); > >> +int pci_set_pcie_reset_state(struct pci_dev *dev, > >> + enum pcie_reset_state state, int probe); > >> int pci_set_cacheline_size(struct pci_dev *dev); > >> #define HAVE_PCI_SET_MWI > >> int __must_check pci_set_mwi(struct pci_dev *dev); > >> @@ -1648,7 +1649,7 @@ extern unsigned long pci_hotplug_mem_size; > >> void pcibios_disable_device(struct pci_dev *dev); > >> void pcibios_set_master(struct pci_dev *dev); > >> int pcibios_set_pcie_reset_state(struct pci_dev *dev, > >> - enum pcie_reset_state state); > >> + enum pcie_reset_state state, int probe); > >> int pcibios_add_device(struct pci_dev *dev); > >> void pcibios_release_device(struct pci_dev *dev); > >> void pcibios_penalize_isa_irq(int irq, int active); > > > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sun, Mar 22, 2015 at 10:06:01PM -0600, Alex Williamson wrote: >On Mon, 2015-03-23 at 14:56 +1100, Gavin Shan wrote: >> On Sun, Mar 22, 2015 at 09:34:33PM -0600, Alex Williamson wrote: >> >On Mon, 2015-03-23 at 14:02 +1100, Gavin Shan wrote: >> >> The patch adds one more parameter ("probe") to pci_set_pcie_reset_state(), >> >> which allows to check if one particular PCI device can be resetted by the >> >> function. The function will be reused to support PCI device specific methods >> >> maintained in pci_dev_reset_methods[] in subsequent patch. >> >> >> >> Cc: Brian King <brking@us.ibm.com> >> >> Cc: Frank Haverkamp <haver@linux.vnet.ibm.com> >> >> Cc: Ian Munsie <imunsie@au1.ibm.com> >> >> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> >> >> --- >> >> v3: Fix arguments of pci_set_pcie_reset_state() in cxl driver >> >> v2: Reimplemented based on pci_set_pcie_reset_state() >> >> --- >> >> arch/powerpc/kernel/eeh.c | 14 ++++++++++---- >> >> drivers/misc/cxl/pci.c | 2 +- >> >> drivers/misc/genwqe/card_base.c | 9 +++++++-- >> >> drivers/pci/pci.c | 15 +++++++++------ >> >> drivers/scsi/ipr.c | 5 +++-- >> >> include/linux/pci.h | 5 +++-- >> >> 6 files changed, 33 insertions(+), 17 deletions(-) >> > >> > >> >Argh, you're trying to make pci_set_pcie_reset_state() compatible with >> >pci_dev_specific_reset(), so it can be called via pci_reset_function(), >> >but the whole point of the pci_reset_function() interface is to reset a >> >*single* function without disturbing anything else. These patches make >> >no effort at all to limit the set of affected devices to a single >> >function and take great liberties using PCI_ANY_ID for vendors. My take >> >on the powerpc version of pcibios_set_pcie_reset_state() is that it's >> >effectively a slot reset, so why not hook into the >> >pci_reset_hotplug_slot() via the hotplug slot ops? Please also use >> >cover letters. Thanks, >> > >> >> Yep, that's the point and intention of the patches. pcibios_set_pcie_reset_state() >> isn't equal to pci_reset_hotplug_slot(). The later one depends on PCI slot, which >> wasn't populated on PowerNV platform yet, but pcibios_set_pcie_reseet_state() doesn't. >> >> The patchset depends on improved pcibios_set_pcie_reset_state(), which can be seen >> from following linked. With it, we don't affect any PCI devices as the config space >> is saved/restored accordingly before/after reset: >> >> https://patchwork.ozlabs.org/patch/438598/ > >Sorry, that's wrong. pci_reset_function() can be called while other >devices in the same multifunction package are actively in use. It >doesn't matter that you're saving and restoring the external state of >the device, the internal state is lost and operation of the device is >interrupted. That is not how pci_reset_function() is supposed to work. >Thanks, > pcibios_set_pcie_reset_state() applies hot reset on PCI bus, or PCI slot fundamental reset essentially. It's potentially affecting multiple PCI devices (not functions). Yes. It's not safe to call pcibios_set_pcie_reset_state() if some of the target functions are actively and in use. I also suspect if it works to reset function#0 via pci_reset_function() while function#1 is actively in use? I guess the caller of pci_reset_function() perhaps has to ensure there are no active functions/devices. One of the issues the patches try to fix: some of broadcom adapters have multile functions, which can't support FLR, AF FLR, PM reset. Also, reset on parent PCI bus and the corresponding reset can't be applied because of they're multi-function package. In summary, pci_reset_function() doesn't work on the adapters. That won't give clean state when passing device from host to guest, or return it back to host. Sometimes, the host memory gets corrupted when destorying the guest. Occasionally, the patches with improved pcibios_set_pcie_reset_state() avoided the issue. Some adapters might require fundamental reset on the PCI slot, or hot reset on parent bus explicitly, in order to successfully reload its firmware after reset. Thanks, Gavin >Alex > >> >> diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c >> >> index daa68a1..cd85c18 100644 >> >> --- a/arch/powerpc/kernel/eeh.c >> >> +++ b/arch/powerpc/kernel/eeh.c >> >> @@ -726,11 +726,14 @@ static void *eeh_restore_dev_state(void *data, void *userdata) >> >> * pcibios_set_pcie_slot_reset - Set PCI-E reset state >> >> * @dev: pci device struct >> >> * @state: reset state to enter >> >> + * @probe: check if the device can take the reset >> >> * >> >> * Return value: >> >> * 0 if success >> >> */ >> >> -int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) >> >> +int pcibios_set_pcie_reset_state(struct pci_dev *dev, >> >> + enum pcie_reset_state state, >> >> + int probe) >> >> { >> >> struct eeh_dev *edev = pci_dev_to_eeh_dev(dev); >> >> struct eeh_pe *pe = eeh_dev_to_pe(edev); >> >> @@ -738,9 +741,12 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat >> >> if (!pe) { >> >> pr_err("%s: No PE found on PCI device %s\n", >> >> __func__, pci_name(dev)); >> >> - return -EINVAL; >> >> + return -ENOTTY; >> >> } >> >> >> >> + if (probe) >> >> + return 0; >> >> + >> >> switch (state) { >> >> case pcie_deassert_reset: >> >> eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); >> >> @@ -762,8 +768,8 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat >> >> break; >> >> default: >> >> eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED); >> >> - return -EINVAL; >> >> - }; >> >> + return -ENOTTY; >> >> + } >> >> >> >> return 0; >> >> } >> >> diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c >> >> index 1ef0164..3a87bfc 100644 >> >> --- a/drivers/misc/cxl/pci.c >> >> +++ b/drivers/misc/cxl/pci.c >> >> @@ -789,7 +789,7 @@ int cxl_reset(struct cxl *adapter) >> >> /* pcie_warm_reset requests a fundamental pci reset which includes a >> >> * PERST assert/deassert. PERST triggers a loading of the image >> >> * if "user" or "factory" is selected in sysfs */ >> >> - if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset))) { >> >> + if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset, 0))) { >> >> dev_err(&dev->dev, "cxl: pcie_warm_reset failed\n"); >> >> return rc; >> >> } >> >> diff --git a/drivers/misc/genwqe/card_base.c b/drivers/misc/genwqe/card_base.c >> >> index 4cf8f82..4871f69 100644 >> >> --- a/drivers/misc/genwqe/card_base.c >> >> +++ b/drivers/misc/genwqe/card_base.c >> >> @@ -782,17 +782,22 @@ static int genwqe_pci_fundamental_reset(struct pci_dev *pci_dev) >> >> { >> >> int rc; >> >> >> >> + /* Probe if the device can take the reset */ >> >> + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 1); >> >> + if (rc) >> >> + return rc; >> >> + >> >> /* >> >> * lock pci config space access from userspace, >> >> * save state and issue PCIe fundamental reset >> >> */ >> >> pci_cfg_access_lock(pci_dev); >> >> pci_save_state(pci_dev); >> >> - rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset); >> >> + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 0); >> >> if (!rc) { >> >> /* keep PCIe reset asserted for 250ms */ >> >> msleep(250); >> >> - pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset); >> >> + pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset, 0); >> >> /* Wait for 2s to reload flash and train the link */ >> >> msleep(2000); >> >> } >> >> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c >> >> index 81f06e8..8581a5f 100644 >> >> --- a/drivers/pci/pci.c >> >> +++ b/drivers/pci/pci.c >> >> @@ -1558,28 +1558,31 @@ EXPORT_SYMBOL(pci_disable_device); >> >> * pcibios_set_pcie_reset_state - set reset state for device dev >> >> * @dev: the PCIe device reset >> >> * @state: Reset state to enter into >> >> - * >> >> + * @probe: Check if the device can take the reset >> >> * >> >> * Sets the PCIe reset state for the device. This is the default >> >> * implementation. Architecture implementations can override this. >> >> */ >> >> int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev, >> >> - enum pcie_reset_state state) >> >> + enum pcie_reset_state state, >> >> + int probe) >> >> { >> >> - return -EINVAL; >> >> + return -ENOTTY; >> >> } >> >> >> >> /** >> >> * pci_set_pcie_reset_state - set reset state for device dev >> >> * @dev: the PCIe device reset >> >> * @state: Reset state to enter into >> >> - * >> >> + * @probe: Check if the device can take the reset >> >> * >> >> * Sets the PCI reset state for the device. >> >> */ >> >> -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) >> >> +int pci_set_pcie_reset_state(struct pci_dev *dev, >> >> + enum pcie_reset_state state, >> >> + int probe) >> >> { >> >> - return pcibios_set_pcie_reset_state(dev, state); >> >> + return pcibios_set_pcie_reset_state(dev, state, probe); >> >> } >> >> EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state); >> >> >> >> diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c >> >> index 9219953..89026f4 100644 >> >> --- a/drivers/scsi/ipr.c >> >> +++ b/drivers/scsi/ipr.c >> >> @@ -8317,7 +8317,8 @@ static int ipr_reset_start_bist(struct ipr_cmnd *ipr_cmd) >> >> static int ipr_reset_slot_reset_done(struct ipr_cmnd *ipr_cmd) >> >> { >> >> ENTER; >> >> - pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, pcie_deassert_reset); >> >> + pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, >> >> + pcie_deassert_reset, 0); >> >> ipr_cmd->job_step = ipr_reset_bist_done; >> >> ipr_reset_start_timer(ipr_cmd, IPR_WAIT_FOR_BIST_TIMEOUT); >> >> LEAVE; >> >> @@ -8339,7 +8340,7 @@ static int ipr_reset_slot_reset(struct ipr_cmnd *ipr_cmd) >> >> struct pci_dev *pdev = ioa_cfg->pdev; >> >> >> >> ENTER; >> >> - pci_set_pcie_reset_state(pdev, pcie_warm_reset); >> >> + pci_set_pcie_reset_state(pdev, pcie_warm_reset, 0); >> >> ipr_cmd->job_step = ipr_reset_slot_reset_done; >> >> ipr_reset_start_timer(ipr_cmd, IPR_PCI_RESET_TIMEOUT); >> >> LEAVE; >> >> diff --git a/include/linux/pci.h b/include/linux/pci.h >> >> index 4e1f17d..052ac63 100644 >> >> --- a/include/linux/pci.h >> >> +++ b/include/linux/pci.h >> >> @@ -960,7 +960,8 @@ extern unsigned int pcibios_max_latency; >> >> void pci_set_master(struct pci_dev *dev); >> >> void pci_clear_master(struct pci_dev *dev); >> >> >> >> -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state); >> >> +int pci_set_pcie_reset_state(struct pci_dev *dev, >> >> + enum pcie_reset_state state, int probe); >> >> int pci_set_cacheline_size(struct pci_dev *dev); >> >> #define HAVE_PCI_SET_MWI >> >> int __must_check pci_set_mwi(struct pci_dev *dev); >> >> @@ -1648,7 +1649,7 @@ extern unsigned long pci_hotplug_mem_size; >> >> void pcibios_disable_device(struct pci_dev *dev); >> >> void pcibios_set_master(struct pci_dev *dev); >> >> int pcibios_set_pcie_reset_state(struct pci_dev *dev, >> >> - enum pcie_reset_state state); >> >> + enum pcie_reset_state state, int probe); >> >> int pcibios_add_device(struct pci_dev *dev); >> >> void pcibios_release_device(struct pci_dev *dev); >> >> void pcibios_penalize_isa_irq(int irq, int active); >> > >> > >> > >> > > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 2015-03-23 at 15:40 +1100, Gavin Shan wrote: > On Sun, Mar 22, 2015 at 10:06:01PM -0600, Alex Williamson wrote: > >On Mon, 2015-03-23 at 14:56 +1100, Gavin Shan wrote: > >> On Sun, Mar 22, 2015 at 09:34:33PM -0600, Alex Williamson wrote: > >> >On Mon, 2015-03-23 at 14:02 +1100, Gavin Shan wrote: > >> >> The patch adds one more parameter ("probe") to pci_set_pcie_reset_state(), > >> >> which allows to check if one particular PCI device can be resetted by the > >> >> function. The function will be reused to support PCI device specific methods > >> >> maintained in pci_dev_reset_methods[] in subsequent patch. > >> >> > >> >> Cc: Brian King <brking@us.ibm.com> > >> >> Cc: Frank Haverkamp <haver@linux.vnet.ibm.com> > >> >> Cc: Ian Munsie <imunsie@au1.ibm.com> > >> >> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> > >> >> --- > >> >> v3: Fix arguments of pci_set_pcie_reset_state() in cxl driver > >> >> v2: Reimplemented based on pci_set_pcie_reset_state() > >> >> --- > >> >> arch/powerpc/kernel/eeh.c | 14 ++++++++++---- > >> >> drivers/misc/cxl/pci.c | 2 +- > >> >> drivers/misc/genwqe/card_base.c | 9 +++++++-- > >> >> drivers/pci/pci.c | 15 +++++++++------ > >> >> drivers/scsi/ipr.c | 5 +++-- > >> >> include/linux/pci.h | 5 +++-- > >> >> 6 files changed, 33 insertions(+), 17 deletions(-) > >> > > >> > > >> >Argh, you're trying to make pci_set_pcie_reset_state() compatible with > >> >pci_dev_specific_reset(), so it can be called via pci_reset_function(), > >> >but the whole point of the pci_reset_function() interface is to reset a > >> >*single* function without disturbing anything else. These patches make > >> >no effort at all to limit the set of affected devices to a single > >> >function and take great liberties using PCI_ANY_ID for vendors. My take > >> >on the powerpc version of pcibios_set_pcie_reset_state() is that it's > >> >effectively a slot reset, so why not hook into the > >> >pci_reset_hotplug_slot() via the hotplug slot ops? Please also use > >> >cover letters. Thanks, > >> > > >> > >> Yep, that's the point and intention of the patches. pcibios_set_pcie_reset_state() > >> isn't equal to pci_reset_hotplug_slot(). The later one depends on PCI slot, which > >> wasn't populated on PowerNV platform yet, but pcibios_set_pcie_reseet_state() doesn't. > >> > >> The patchset depends on improved pcibios_set_pcie_reset_state(), which can be seen > >> from following linked. With it, we don't affect any PCI devices as the config space > >> is saved/restored accordingly before/after reset: > >> > >> https://patchwork.ozlabs.org/patch/438598/ > > > >Sorry, that's wrong. pci_reset_function() can be called while other > >devices in the same multifunction package are actively in use. It > >doesn't matter that you're saving and restoring the external state of > >the device, the internal state is lost and operation of the device is > >interrupted. That is not how pci_reset_function() is supposed to work. > >Thanks, > > > > pcibios_set_pcie_reset_state() applies hot reset on PCI bus, or PCI > slot fundamental reset essentially. It's potentially affecting multiple > PCI devices (not functions). > > Yes. It's not safe to call pcibios_set_pcie_reset_state() if some of > the target functions are actively and in use. I also suspect if it > works to reset function#0 via pci_reset_function() while function#1 > is actively in use? I guess the caller of pci_reset_function() perhaps > has to ensure there are no active functions/devices. > > One of the issues the patches try to fix: some of broadcom adapters have > multile functions, which can't support FLR, AF FLR, PM reset. Also, reset > on parent PCI bus and the corresponding reset can't be applied because of > they're multi-function package. In summary, pci_reset_function() doesn't > work on the adapters. That won't give clean state when passing device from > host to guest, or return it back to host. Sometimes, the host memory gets > corrupted when destorying the guest. Occasionally, the patches with improved > pcibios_set_pcie_reset_state() avoided the issue. > > Some adapters might require fundamental reset on the PCI slot, or hot reset > on parent bus explicitly, in order to successfully reload its firmware after > reset. This is exactly why we have pci_reset_slot() and pci_reset_bus(), so that the caller can manage the scope of the reset. You cannot change the semantics of pci_reset_function() simply because it's convenient for your implementation. This series is wrong and should not be applied. Thanks, Alex > >> >> diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c > >> >> index daa68a1..cd85c18 100644 > >> >> --- a/arch/powerpc/kernel/eeh.c > >> >> +++ b/arch/powerpc/kernel/eeh.c > >> >> @@ -726,11 +726,14 @@ static void *eeh_restore_dev_state(void *data, void *userdata) > >> >> * pcibios_set_pcie_slot_reset - Set PCI-E reset state > >> >> * @dev: pci device struct > >> >> * @state: reset state to enter > >> >> + * @probe: check if the device can take the reset > >> >> * > >> >> * Return value: > >> >> * 0 if success > >> >> */ > >> >> -int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) > >> >> +int pcibios_set_pcie_reset_state(struct pci_dev *dev, > >> >> + enum pcie_reset_state state, > >> >> + int probe) > >> >> { > >> >> struct eeh_dev *edev = pci_dev_to_eeh_dev(dev); > >> >> struct eeh_pe *pe = eeh_dev_to_pe(edev); > >> >> @@ -738,9 +741,12 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat > >> >> if (!pe) { > >> >> pr_err("%s: No PE found on PCI device %s\n", > >> >> __func__, pci_name(dev)); > >> >> - return -EINVAL; > >> >> + return -ENOTTY; > >> >> } > >> >> > >> >> + if (probe) > >> >> + return 0; > >> >> + > >> >> switch (state) { > >> >> case pcie_deassert_reset: > >> >> eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); > >> >> @@ -762,8 +768,8 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat > >> >> break; > >> >> default: > >> >> eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED); > >> >> - return -EINVAL; > >> >> - }; > >> >> + return -ENOTTY; > >> >> + } > >> >> > >> >> return 0; > >> >> } > >> >> diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c > >> >> index 1ef0164..3a87bfc 100644 > >> >> --- a/drivers/misc/cxl/pci.c > >> >> +++ b/drivers/misc/cxl/pci.c > >> >> @@ -789,7 +789,7 @@ int cxl_reset(struct cxl *adapter) > >> >> /* pcie_warm_reset requests a fundamental pci reset which includes a > >> >> * PERST assert/deassert. PERST triggers a loading of the image > >> >> * if "user" or "factory" is selected in sysfs */ > >> >> - if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset))) { > >> >> + if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset, 0))) { > >> >> dev_err(&dev->dev, "cxl: pcie_warm_reset failed\n"); > >> >> return rc; > >> >> } > >> >> diff --git a/drivers/misc/genwqe/card_base.c b/drivers/misc/genwqe/card_base.c > >> >> index 4cf8f82..4871f69 100644 > >> >> --- a/drivers/misc/genwqe/card_base.c > >> >> +++ b/drivers/misc/genwqe/card_base.c > >> >> @@ -782,17 +782,22 @@ static int genwqe_pci_fundamental_reset(struct pci_dev *pci_dev) > >> >> { > >> >> int rc; > >> >> > >> >> + /* Probe if the device can take the reset */ > >> >> + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 1); > >> >> + if (rc) > >> >> + return rc; > >> >> + > >> >> /* > >> >> * lock pci config space access from userspace, > >> >> * save state and issue PCIe fundamental reset > >> >> */ > >> >> pci_cfg_access_lock(pci_dev); > >> >> pci_save_state(pci_dev); > >> >> - rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset); > >> >> + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 0); > >> >> if (!rc) { > >> >> /* keep PCIe reset asserted for 250ms */ > >> >> msleep(250); > >> >> - pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset); > >> >> + pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset, 0); > >> >> /* Wait for 2s to reload flash and train the link */ > >> >> msleep(2000); > >> >> } > >> >> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > >> >> index 81f06e8..8581a5f 100644 > >> >> --- a/drivers/pci/pci.c > >> >> +++ b/drivers/pci/pci.c > >> >> @@ -1558,28 +1558,31 @@ EXPORT_SYMBOL(pci_disable_device); > >> >> * pcibios_set_pcie_reset_state - set reset state for device dev > >> >> * @dev: the PCIe device reset > >> >> * @state: Reset state to enter into > >> >> - * > >> >> + * @probe: Check if the device can take the reset > >> >> * > >> >> * Sets the PCIe reset state for the device. This is the default > >> >> * implementation. Architecture implementations can override this. > >> >> */ > >> >> int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev, > >> >> - enum pcie_reset_state state) > >> >> + enum pcie_reset_state state, > >> >> + int probe) > >> >> { > >> >> - return -EINVAL; > >> >> + return -ENOTTY; > >> >> } > >> >> > >> >> /** > >> >> * pci_set_pcie_reset_state - set reset state for device dev > >> >> * @dev: the PCIe device reset > >> >> * @state: Reset state to enter into > >> >> - * > >> >> + * @probe: Check if the device can take the reset > >> >> * > >> >> * Sets the PCI reset state for the device. > >> >> */ > >> >> -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) > >> >> +int pci_set_pcie_reset_state(struct pci_dev *dev, > >> >> + enum pcie_reset_state state, > >> >> + int probe) > >> >> { > >> >> - return pcibios_set_pcie_reset_state(dev, state); > >> >> + return pcibios_set_pcie_reset_state(dev, state, probe); > >> >> } > >> >> EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state); > >> >> > >> >> diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c > >> >> index 9219953..89026f4 100644 > >> >> --- a/drivers/scsi/ipr.c > >> >> +++ b/drivers/scsi/ipr.c > >> >> @@ -8317,7 +8317,8 @@ static int ipr_reset_start_bist(struct ipr_cmnd *ipr_cmd) > >> >> static int ipr_reset_slot_reset_done(struct ipr_cmnd *ipr_cmd) > >> >> { > >> >> ENTER; > >> >> - pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, pcie_deassert_reset); > >> >> + pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, > >> >> + pcie_deassert_reset, 0); > >> >> ipr_cmd->job_step = ipr_reset_bist_done; > >> >> ipr_reset_start_timer(ipr_cmd, IPR_WAIT_FOR_BIST_TIMEOUT); > >> >> LEAVE; > >> >> @@ -8339,7 +8340,7 @@ static int ipr_reset_slot_reset(struct ipr_cmnd *ipr_cmd) > >> >> struct pci_dev *pdev = ioa_cfg->pdev; > >> >> > >> >> ENTER; > >> >> - pci_set_pcie_reset_state(pdev, pcie_warm_reset); > >> >> + pci_set_pcie_reset_state(pdev, pcie_warm_reset, 0); > >> >> ipr_cmd->job_step = ipr_reset_slot_reset_done; > >> >> ipr_reset_start_timer(ipr_cmd, IPR_PCI_RESET_TIMEOUT); > >> >> LEAVE; > >> >> diff --git a/include/linux/pci.h b/include/linux/pci.h > >> >> index 4e1f17d..052ac63 100644 > >> >> --- a/include/linux/pci.h > >> >> +++ b/include/linux/pci.h > >> >> @@ -960,7 +960,8 @@ extern unsigned int pcibios_max_latency; > >> >> void pci_set_master(struct pci_dev *dev); > >> >> void pci_clear_master(struct pci_dev *dev); > >> >> > >> >> -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state); > >> >> +int pci_set_pcie_reset_state(struct pci_dev *dev, > >> >> + enum pcie_reset_state state, int probe); > >> >> int pci_set_cacheline_size(struct pci_dev *dev); > >> >> #define HAVE_PCI_SET_MWI > >> >> int __must_check pci_set_mwi(struct pci_dev *dev); > >> >> @@ -1648,7 +1649,7 @@ extern unsigned long pci_hotplug_mem_size; > >> >> void pcibios_disable_device(struct pci_dev *dev); > >> >> void pcibios_set_master(struct pci_dev *dev); > >> >> int pcibios_set_pcie_reset_state(struct pci_dev *dev, > >> >> - enum pcie_reset_state state); > >> >> + enum pcie_reset_state state, int probe); > >> >> int pcibios_add_device(struct pci_dev *dev); > >> >> void pcibios_release_device(struct pci_dev *dev); > >> >> void pcibios_penalize_isa_irq(int irq, int active); > >> > > >> > > >> > > >> > > > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Mar 23, 2015 at 06:40:34AM -0600, Alex Williamson wrote: > On Mon, 2015-03-23 at 15:40 +1100, Gavin Shan wrote: > > On Sun, Mar 22, 2015 at 10:06:01PM -0600, Alex Williamson wrote: > > >On Mon, 2015-03-23 at 14:56 +1100, Gavin Shan wrote: > > >> On Sun, Mar 22, 2015 at 09:34:33PM -0600, Alex Williamson wrote: > > >> >On Mon, 2015-03-23 at 14:02 +1100, Gavin Shan wrote: > > >> >> The patch adds one more parameter ("probe") to pci_set_pcie_reset_state(), > > >> >> which allows to check if one particular PCI device can be resetted by the > > >> >> function. The function will be reused to support PCI device specific methods > > >> >> maintained in pci_dev_reset_methods[] in subsequent patch. > > >> >> > > >> >> Cc: Brian King <brking@us.ibm.com> > > >> >> Cc: Frank Haverkamp <haver@linux.vnet.ibm.com> > > >> >> Cc: Ian Munsie <imunsie@au1.ibm.com> > > >> >> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> > > >> >> --- > > >> >> v3: Fix arguments of pci_set_pcie_reset_state() in cxl driver > > >> >> v2: Reimplemented based on pci_set_pcie_reset_state() > > >> >> --- > > >> >> arch/powerpc/kernel/eeh.c | 14 ++++++++++---- > > >> >> drivers/misc/cxl/pci.c | 2 +- > > >> >> drivers/misc/genwqe/card_base.c | 9 +++++++-- > > >> >> drivers/pci/pci.c | 15 +++++++++------ > > >> >> drivers/scsi/ipr.c | 5 +++-- > > >> >> include/linux/pci.h | 5 +++-- > > >> >> 6 files changed, 33 insertions(+), 17 deletions(-) > > >> > > > >> > > > >> >Argh, you're trying to make pci_set_pcie_reset_state() compatible with > > >> >pci_dev_specific_reset(), so it can be called via pci_reset_function(), > > >> >but the whole point of the pci_reset_function() interface is to reset a > > >> >*single* function without disturbing anything else. These patches make > > >> >no effort at all to limit the set of affected devices to a single > > >> >function and take great liberties using PCI_ANY_ID for vendors. My take > > >> >on the powerpc version of pcibios_set_pcie_reset_state() is that it's > > >> >effectively a slot reset, so why not hook into the > > >> >pci_reset_hotplug_slot() via the hotplug slot ops? Please also use > > >> >cover letters. Thanks, > > >> > > > >> > > >> Yep, that's the point and intention of the patches. pcibios_set_pcie_reset_state() > > >> isn't equal to pci_reset_hotplug_slot(). The later one depends on PCI slot, which > > >> wasn't populated on PowerNV platform yet, but pcibios_set_pcie_reseet_state() doesn't. > > >> > > >> The patchset depends on improved pcibios_set_pcie_reset_state(), which can be seen > > >> from following linked. With it, we don't affect any PCI devices as the config space > > >> is saved/restored accordingly before/after reset: > > >> > > >> https://patchwork.ozlabs.org/patch/438598/ > > > > > >Sorry, that's wrong. pci_reset_function() can be called while other > > >devices in the same multifunction package are actively in use. It > > >doesn't matter that you're saving and restoring the external state of > > >the device, the internal state is lost and operation of the device is > > >interrupted. That is not how pci_reset_function() is supposed to work. > > >Thanks, > > > > > > > pcibios_set_pcie_reset_state() applies hot reset on PCI bus, or PCI > > slot fundamental reset essentially. It's potentially affecting multiple > > PCI devices (not functions). > > > > Yes. It's not safe to call pcibios_set_pcie_reset_state() if some of > > the target functions are actively and in use. I also suspect if it > > works to reset function#0 via pci_reset_function() while function#1 > > is actively in use? I guess the caller of pci_reset_function() perhaps > > has to ensure there are no active functions/devices. > > > > One of the issues the patches try to fix: some of broadcom adapters have > > multile functions, which can't support FLR, AF FLR, PM reset. Also, reset > > on parent PCI bus and the corresponding reset can't be applied because of > > they're multi-function package. In summary, pci_reset_function() doesn't > > work on the adapters. That won't give clean state when passing device from > > host to guest, or return it back to host. Sometimes, the host memory gets > > corrupted when destorying the guest. Occasionally, the patches with improved > > pcibios_set_pcie_reset_state() avoided the issue. > > > > Some adapters might require fundamental reset on the PCI slot, or hot reset > > on parent bus explicitly, in order to successfully reload its firmware after > > reset. > > This is exactly why we have pci_reset_slot() and pci_reset_bus(), so > that the caller can manage the scope of the reset. You cannot change > the semantics of pci_reset_function() simply because it's convenient for > your implementation. This series is wrong and should not be applied. > Thanks, > > Alex > Alex, I agree with you here. I think the bigger issue is that we are not making sure VFIO is secure, allowing functions to be assigned separately to different guests, even when we cannot guarantee we can safely reset a single function, and also ignoring the possibility of internal communication between functions. This second problem is real, since some adapters will allow firmware to be loaded or reset, which will affect other functions. We need to either have in written that this is acceptable and that higher layers should take care of these possibilities, if they care about them, or we need to fix this, by making VFIO only accept a whole group of functions to be assigned to a guest, which will allow the problem described by Gavin to be properly handled, by using slot reset functions, or another way of grouping devices that may be specific to the platform. Does it make sense? Cascardo. > > >> >> diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c > > >> >> index daa68a1..cd85c18 100644 > > >> >> --- a/arch/powerpc/kernel/eeh.c > > >> >> +++ b/arch/powerpc/kernel/eeh.c > > >> >> @@ -726,11 +726,14 @@ static void *eeh_restore_dev_state(void *data, void *userdata) > > >> >> * pcibios_set_pcie_slot_reset - Set PCI-E reset state > > >> >> * @dev: pci device struct > > >> >> * @state: reset state to enter > > >> >> + * @probe: check if the device can take the reset > > >> >> * > > >> >> * Return value: > > >> >> * 0 if success > > >> >> */ > > >> >> -int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) > > >> >> +int pcibios_set_pcie_reset_state(struct pci_dev *dev, > > >> >> + enum pcie_reset_state state, > > >> >> + int probe) > > >> >> { > > >> >> struct eeh_dev *edev = pci_dev_to_eeh_dev(dev); > > >> >> struct eeh_pe *pe = eeh_dev_to_pe(edev); > > >> >> @@ -738,9 +741,12 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat > > >> >> if (!pe) { > > >> >> pr_err("%s: No PE found on PCI device %s\n", > > >> >> __func__, pci_name(dev)); > > >> >> - return -EINVAL; > > >> >> + return -ENOTTY; > > >> >> } > > >> >> > > >> >> + if (probe) > > >> >> + return 0; > > >> >> + > > >> >> switch (state) { > > >> >> case pcie_deassert_reset: > > >> >> eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); > > >> >> @@ -762,8 +768,8 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat > > >> >> break; > > >> >> default: > > >> >> eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED); > > >> >> - return -EINVAL; > > >> >> - }; > > >> >> + return -ENOTTY; > > >> >> + } > > >> >> > > >> >> return 0; > > >> >> } > > >> >> diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c > > >> >> index 1ef0164..3a87bfc 100644 > > >> >> --- a/drivers/misc/cxl/pci.c > > >> >> +++ b/drivers/misc/cxl/pci.c > > >> >> @@ -789,7 +789,7 @@ int cxl_reset(struct cxl *adapter) > > >> >> /* pcie_warm_reset requests a fundamental pci reset which includes a > > >> >> * PERST assert/deassert. PERST triggers a loading of the image > > >> >> * if "user" or "factory" is selected in sysfs */ > > >> >> - if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset))) { > > >> >> + if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset, 0))) { > > >> >> dev_err(&dev->dev, "cxl: pcie_warm_reset failed\n"); > > >> >> return rc; > > >> >> } > > >> >> diff --git a/drivers/misc/genwqe/card_base.c b/drivers/misc/genwqe/card_base.c > > >> >> index 4cf8f82..4871f69 100644 > > >> >> --- a/drivers/misc/genwqe/card_base.c > > >> >> +++ b/drivers/misc/genwqe/card_base.c > > >> >> @@ -782,17 +782,22 @@ static int genwqe_pci_fundamental_reset(struct pci_dev *pci_dev) > > >> >> { > > >> >> int rc; > > >> >> > > >> >> + /* Probe if the device can take the reset */ > > >> >> + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 1); > > >> >> + if (rc) > > >> >> + return rc; > > >> >> + > > >> >> /* > > >> >> * lock pci config space access from userspace, > > >> >> * save state and issue PCIe fundamental reset > > >> >> */ > > >> >> pci_cfg_access_lock(pci_dev); > > >> >> pci_save_state(pci_dev); > > >> >> - rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset); > > >> >> + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 0); > > >> >> if (!rc) { > > >> >> /* keep PCIe reset asserted for 250ms */ > > >> >> msleep(250); > > >> >> - pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset); > > >> >> + pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset, 0); > > >> >> /* Wait for 2s to reload flash and train the link */ > > >> >> msleep(2000); > > >> >> } > > >> >> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > >> >> index 81f06e8..8581a5f 100644 > > >> >> --- a/drivers/pci/pci.c > > >> >> +++ b/drivers/pci/pci.c > > >> >> @@ -1558,28 +1558,31 @@ EXPORT_SYMBOL(pci_disable_device); > > >> >> * pcibios_set_pcie_reset_state - set reset state for device dev > > >> >> * @dev: the PCIe device reset > > >> >> * @state: Reset state to enter into > > >> >> - * > > >> >> + * @probe: Check if the device can take the reset > > >> >> * > > >> >> * Sets the PCIe reset state for the device. This is the default > > >> >> * implementation. Architecture implementations can override this. > > >> >> */ > > >> >> int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev, > > >> >> - enum pcie_reset_state state) > > >> >> + enum pcie_reset_state state, > > >> >> + int probe) > > >> >> { > > >> >> - return -EINVAL; > > >> >> + return -ENOTTY; > > >> >> } > > >> >> > > >> >> /** > > >> >> * pci_set_pcie_reset_state - set reset state for device dev > > >> >> * @dev: the PCIe device reset > > >> >> * @state: Reset state to enter into > > >> >> - * > > >> >> + * @probe: Check if the device can take the reset > > >> >> * > > >> >> * Sets the PCI reset state for the device. > > >> >> */ > > >> >> -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) > > >> >> +int pci_set_pcie_reset_state(struct pci_dev *dev, > > >> >> + enum pcie_reset_state state, > > >> >> + int probe) > > >> >> { > > >> >> - return pcibios_set_pcie_reset_state(dev, state); > > >> >> + return pcibios_set_pcie_reset_state(dev, state, probe); > > >> >> } > > >> >> EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state); > > >> >> > > >> >> diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c > > >> >> index 9219953..89026f4 100644 > > >> >> --- a/drivers/scsi/ipr.c > > >> >> +++ b/drivers/scsi/ipr.c > > >> >> @@ -8317,7 +8317,8 @@ static int ipr_reset_start_bist(struct ipr_cmnd *ipr_cmd) > > >> >> static int ipr_reset_slot_reset_done(struct ipr_cmnd *ipr_cmd) > > >> >> { > > >> >> ENTER; > > >> >> - pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, pcie_deassert_reset); > > >> >> + pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, > > >> >> + pcie_deassert_reset, 0); > > >> >> ipr_cmd->job_step = ipr_reset_bist_done; > > >> >> ipr_reset_start_timer(ipr_cmd, IPR_WAIT_FOR_BIST_TIMEOUT); > > >> >> LEAVE; > > >> >> @@ -8339,7 +8340,7 @@ static int ipr_reset_slot_reset(struct ipr_cmnd *ipr_cmd) > > >> >> struct pci_dev *pdev = ioa_cfg->pdev; > > >> >> > > >> >> ENTER; > > >> >> - pci_set_pcie_reset_state(pdev, pcie_warm_reset); > > >> >> + pci_set_pcie_reset_state(pdev, pcie_warm_reset, 0); > > >> >> ipr_cmd->job_step = ipr_reset_slot_reset_done; > > >> >> ipr_reset_start_timer(ipr_cmd, IPR_PCI_RESET_TIMEOUT); > > >> >> LEAVE; > > >> >> diff --git a/include/linux/pci.h b/include/linux/pci.h > > >> >> index 4e1f17d..052ac63 100644 > > >> >> --- a/include/linux/pci.h > > >> >> +++ b/include/linux/pci.h > > >> >> @@ -960,7 +960,8 @@ extern unsigned int pcibios_max_latency; > > >> >> void pci_set_master(struct pci_dev *dev); > > >> >> void pci_clear_master(struct pci_dev *dev); > > >> >> > > >> >> -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state); > > >> >> +int pci_set_pcie_reset_state(struct pci_dev *dev, > > >> >> + enum pcie_reset_state state, int probe); > > >> >> int pci_set_cacheline_size(struct pci_dev *dev); > > >> >> #define HAVE_PCI_SET_MWI > > >> >> int __must_check pci_set_mwi(struct pci_dev *dev); > > >> >> @@ -1648,7 +1649,7 @@ extern unsigned long pci_hotplug_mem_size; > > >> >> void pcibios_disable_device(struct pci_dev *dev); > > >> >> void pcibios_set_master(struct pci_dev *dev); > > >> >> int pcibios_set_pcie_reset_state(struct pci_dev *dev, > > >> >> - enum pcie_reset_state state); > > >> >> + enum pcie_reset_state state, int probe); > > >> >> int pcibios_add_device(struct pci_dev *dev); > > >> >> void pcibios_release_device(struct pci_dev *dev); > > >> >> void pcibios_penalize_isa_irq(int irq, int active); > > >> > > > >> > > > >> > > > >> > > > > > > > > > > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 2015-03-23 at 17:07 -0300, cascardo@linux.vnet.ibm.com wrote: > On Mon, Mar 23, 2015 at 06:40:34AM -0600, Alex Williamson wrote: > > On Mon, 2015-03-23 at 15:40 +1100, Gavin Shan wrote: > > > On Sun, Mar 22, 2015 at 10:06:01PM -0600, Alex Williamson wrote: > > > >On Mon, 2015-03-23 at 14:56 +1100, Gavin Shan wrote: > > > >> On Sun, Mar 22, 2015 at 09:34:33PM -0600, Alex Williamson wrote: > > > >> >On Mon, 2015-03-23 at 14:02 +1100, Gavin Shan wrote: > > > >> >> The patch adds one more parameter ("probe") to pci_set_pcie_reset_state(), > > > >> >> which allows to check if one particular PCI device can be resetted by the > > > >> >> function. The function will be reused to support PCI device specific methods > > > >> >> maintained in pci_dev_reset_methods[] in subsequent patch. > > > >> >> > > > >> >> Cc: Brian King <brking@us.ibm.com> > > > >> >> Cc: Frank Haverkamp <haver@linux.vnet.ibm.com> > > > >> >> Cc: Ian Munsie <imunsie@au1.ibm.com> > > > >> >> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> > > > >> >> --- > > > >> >> v3: Fix arguments of pci_set_pcie_reset_state() in cxl driver > > > >> >> v2: Reimplemented based on pci_set_pcie_reset_state() > > > >> >> --- > > > >> >> arch/powerpc/kernel/eeh.c | 14 ++++++++++---- > > > >> >> drivers/misc/cxl/pci.c | 2 +- > > > >> >> drivers/misc/genwqe/card_base.c | 9 +++++++-- > > > >> >> drivers/pci/pci.c | 15 +++++++++------ > > > >> >> drivers/scsi/ipr.c | 5 +++-- > > > >> >> include/linux/pci.h | 5 +++-- > > > >> >> 6 files changed, 33 insertions(+), 17 deletions(-) > > > >> > > > > >> > > > > >> >Argh, you're trying to make pci_set_pcie_reset_state() compatible with > > > >> >pci_dev_specific_reset(), so it can be called via pci_reset_function(), > > > >> >but the whole point of the pci_reset_function() interface is to reset a > > > >> >*single* function without disturbing anything else. These patches make > > > >> >no effort at all to limit the set of affected devices to a single > > > >> >function and take great liberties using PCI_ANY_ID for vendors. My take > > > >> >on the powerpc version of pcibios_set_pcie_reset_state() is that it's > > > >> >effectively a slot reset, so why not hook into the > > > >> >pci_reset_hotplug_slot() via the hotplug slot ops? Please also use > > > >> >cover letters. Thanks, > > > >> > > > > >> > > > >> Yep, that's the point and intention of the patches. pcibios_set_pcie_reset_state() > > > >> isn't equal to pci_reset_hotplug_slot(). The later one depends on PCI slot, which > > > >> wasn't populated on PowerNV platform yet, but pcibios_set_pcie_reseet_state() doesn't. > > > >> > > > >> The patchset depends on improved pcibios_set_pcie_reset_state(), which can be seen > > > >> from following linked. With it, we don't affect any PCI devices as the config space > > > >> is saved/restored accordingly before/after reset: > > > >> > > > >> https://patchwork.ozlabs.org/patch/438598/ > > > > > > > >Sorry, that's wrong. pci_reset_function() can be called while other > > > >devices in the same multifunction package are actively in use. It > > > >doesn't matter that you're saving and restoring the external state of > > > >the device, the internal state is lost and operation of the device is > > > >interrupted. That is not how pci_reset_function() is supposed to work. > > > >Thanks, > > > > > > > > > > pcibios_set_pcie_reset_state() applies hot reset on PCI bus, or PCI > > > slot fundamental reset essentially. It's potentially affecting multiple > > > PCI devices (not functions). > > > > > > Yes. It's not safe to call pcibios_set_pcie_reset_state() if some of > > > the target functions are actively and in use. I also suspect if it > > > works to reset function#0 via pci_reset_function() while function#1 > > > is actively in use? I guess the caller of pci_reset_function() perhaps > > > has to ensure there are no active functions/devices. > > > > > > One of the issues the patches try to fix: some of broadcom adapters have > > > multile functions, which can't support FLR, AF FLR, PM reset. Also, reset > > > on parent PCI bus and the corresponding reset can't be applied because of > > > they're multi-function package. In summary, pci_reset_function() doesn't > > > work on the adapters. That won't give clean state when passing device from > > > host to guest, or return it back to host. Sometimes, the host memory gets > > > corrupted when destorying the guest. Occasionally, the patches with improved > > > pcibios_set_pcie_reset_state() avoided the issue. > > > > > > Some adapters might require fundamental reset on the PCI slot, or hot reset > > > on parent bus explicitly, in order to successfully reload its firmware after > > > reset. > > > > This is exactly why we have pci_reset_slot() and pci_reset_bus(), so > > that the caller can manage the scope of the reset. You cannot change > > the semantics of pci_reset_function() simply because it's convenient for > > your implementation. This series is wrong and should not be applied. > > Thanks, > > > > Alex > > > > > Alex, > > I agree with you here. I think the bigger issue is that we are not > making sure VFIO is secure, allowing functions to be assigned separately > to different guests, even when we cannot guarantee we can safely reset a > single function, and also ignoring the possibility of internal > communication between functions. This second problem is real, since some > adapters will allow firmware to be loaded or reset, which will affect > other functions. > > We need to either have in written that this is acceptable and that > higher layers should take care of these possibilities, if they care > about them, or we need to fix this, by making VFIO only accept a whole > group of functions to be assigned to a guest, which will allow the > problem described by Gavin to be properly handled, by using slot reset > functions, or another way of grouping devices that may be specific to > the platform. > > Does it make sense? I don't know what you're doing on POWER, I thought groups were equivalent to PEs, but on x86 we learn about isolation of PCI functions by standard PCI properties. Devices need to tell us that they're isolated via ACS capabilities (or quirks, with vendor approval). Otherwise we assume there is no isolation and multi-function devices will be grouped together, preventing the individual functions from being assigned to separate userspace instances. VFIO does not ignore the problem of internal communication between functions, it uses ACS... at least on most platforms. Firmware shared between functions is an unsolvable problem outside of restricting device assignment only to SR-IOV virtual functions. We cannot know the programming method to block firmware updates of an assigned device nor can we control which functions share the firmware. If you're worried about this level of attack against the hardware, use VFs exclusively. If you're unsatisfied with the grouping of devices on your platform, this is entirely within your control since VFIO relies on IOMMU groups, which are managed via the platform IOMMU driver. If your IOMMU driver is arbitrarily splitting each PCI function into a separate group without testing the isolation, that's a problem with IOMMU groups on your platform. If you would like to add a reset requirement to a group, you have the ability to do that. On x86, I expect this would be far too restrictive. VFIO also knows how to do bus and slot resets, the pci_reset_bus() and pci_reset_slot() interfaces were added by me with vfio-pci as the first user. Resets are generally handled as best effort though and this is sometimes a property of a device that might make it unsuitable for device assignment. The fact that you're implying above that the devices covered by the device specific reset proposed in this series can be assigned separately makes ignoring the scope of pci_reset_function() all the more wrong. If you want to change grouping on POWER to require that a group can be reset, that's an IOMMU driver issue. If you want to make a change to VFIO to require an opt-in/out of allowing access to groups without a reset, then propose something. Just please don't ignore the semantics of existing functions because it's a quicker and easier hack than doing it correctly. Thanks, Alex -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Mar 23, 2015 at 06:40:34AM -0600, Alex Williamson wrote: >On Mon, 2015-03-23 at 15:40 +1100, Gavin Shan wrote: >> On Sun, Mar 22, 2015 at 10:06:01PM -0600, Alex Williamson wrote: >> >On Mon, 2015-03-23 at 14:56 +1100, Gavin Shan wrote: >> >> On Sun, Mar 22, 2015 at 09:34:33PM -0600, Alex Williamson wrote: >> >> >On Mon, 2015-03-23 at 14:02 +1100, Gavin Shan wrote: >> >> >> The patch adds one more parameter ("probe") to pci_set_pcie_reset_state(), >> >> >> which allows to check if one particular PCI device can be resetted by the >> >> >> function. The function will be reused to support PCI device specific methods >> >> >> maintained in pci_dev_reset_methods[] in subsequent patch. >> >> >> >> >> >> Cc: Brian King <brking@us.ibm.com> >> >> >> Cc: Frank Haverkamp <haver@linux.vnet.ibm.com> >> >> >> Cc: Ian Munsie <imunsie@au1.ibm.com> >> >> >> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> >> >> >> --- >> >> >> v3: Fix arguments of pci_set_pcie_reset_state() in cxl driver >> >> >> v2: Reimplemented based on pci_set_pcie_reset_state() >> >> >> --- >> >> >> arch/powerpc/kernel/eeh.c | 14 ++++++++++---- >> >> >> drivers/misc/cxl/pci.c | 2 +- >> >> >> drivers/misc/genwqe/card_base.c | 9 +++++++-- >> >> >> drivers/pci/pci.c | 15 +++++++++------ >> >> >> drivers/scsi/ipr.c | 5 +++-- >> >> >> include/linux/pci.h | 5 +++-- >> >> >> 6 files changed, 33 insertions(+), 17 deletions(-) >> >> > >> >> > >> >> >Argh, you're trying to make pci_set_pcie_reset_state() compatible with >> >> >pci_dev_specific_reset(), so it can be called via pci_reset_function(), >> >> >but the whole point of the pci_reset_function() interface is to reset a >> >> >*single* function without disturbing anything else. These patches make >> >> >no effort at all to limit the set of affected devices to a single >> >> >function and take great liberties using PCI_ANY_ID for vendors. My take >> >> >on the powerpc version of pcibios_set_pcie_reset_state() is that it's >> >> >effectively a slot reset, so why not hook into the >> >> >pci_reset_hotplug_slot() via the hotplug slot ops? Please also use >> >> >cover letters. Thanks, >> >> > >> >> >> >> Yep, that's the point and intention of the patches. pcibios_set_pcie_reset_state() >> >> isn't equal to pci_reset_hotplug_slot(). The later one depends on PCI slot, which >> >> wasn't populated on PowerNV platform yet, but pcibios_set_pcie_reseet_state() doesn't. >> >> >> >> The patchset depends on improved pcibios_set_pcie_reset_state(), which can be seen >> >> from following linked. With it, we don't affect any PCI devices as the config space >> >> is saved/restored accordingly before/after reset: >> >> >> >> https://patchwork.ozlabs.org/patch/438598/ >> > >> >Sorry, that's wrong. pci_reset_function() can be called while other >> >devices in the same multifunction package are actively in use. It >> >doesn't matter that you're saving and restoring the external state of >> >the device, the internal state is lost and operation of the device is >> >interrupted. That is not how pci_reset_function() is supposed to work. >> >Thanks, >> > >> >> pcibios_set_pcie_reset_state() applies hot reset on PCI bus, or PCI >> slot fundamental reset essentially. It's potentially affecting multiple >> PCI devices (not functions). >> >> Yes. It's not safe to call pcibios_set_pcie_reset_state() if some of >> the target functions are actively and in use. I also suspect if it >> works to reset function#0 via pci_reset_function() while function#1 >> is actively in use? I guess the caller of pci_reset_function() perhaps >> has to ensure there are no active functions/devices. >> >> One of the issues the patches try to fix: some of broadcom adapters have >> multile functions, which can't support FLR, AF FLR, PM reset. Also, reset >> on parent PCI bus and the corresponding reset can't be applied because of >> they're multi-function package. In summary, pci_reset_function() doesn't >> work on the adapters. That won't give clean state when passing device from >> host to guest, or return it back to host. Sometimes, the host memory gets >> corrupted when destorying the guest. Occasionally, the patches with improved >> pcibios_set_pcie_reset_state() avoided the issue. >> >> Some adapters might require fundamental reset on the PCI slot, or hot reset >> on parent bus explicitly, in order to successfully reload its firmware after >> reset. > >This is exactly why we have pci_reset_slot() and pci_reset_bus(), so >that the caller can manage the scope of the reset. You cannot change >the semantics of pci_reset_function() simply because it's convenient for >your implementation. This series is wrong and should not be applied. >Thanks, > Alex, thanks for your review. I agree that the patches changed the semantics of pci_reset_function() and it's wrong direction to take. Actually, the PEs are segmented based on PCI buses (except SRIOV VFs), which means all PCI devices attached to one PCI bus forms one PE, which is the minimal unit for passing through. So the case that 0000:00:00.0 is passed to guest#0, while 0000:00:00.1 is assigned to guest#1, can't happen. Thanks, Gavin >Alex > >> >> >> diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c >> >> >> index daa68a1..cd85c18 100644 >> >> >> --- a/arch/powerpc/kernel/eeh.c >> >> >> +++ b/arch/powerpc/kernel/eeh.c >> >> >> @@ -726,11 +726,14 @@ static void *eeh_restore_dev_state(void *data, void *userdata) >> >> >> * pcibios_set_pcie_slot_reset - Set PCI-E reset state >> >> >> * @dev: pci device struct >> >> >> * @state: reset state to enter >> >> >> + * @probe: check if the device can take the reset >> >> >> * >> >> >> * Return value: >> >> >> * 0 if success >> >> >> */ >> >> >> -int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) >> >> >> +int pcibios_set_pcie_reset_state(struct pci_dev *dev, >> >> >> + enum pcie_reset_state state, >> >> >> + int probe) >> >> >> { >> >> >> struct eeh_dev *edev = pci_dev_to_eeh_dev(dev); >> >> >> struct eeh_pe *pe = eeh_dev_to_pe(edev); >> >> >> @@ -738,9 +741,12 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat >> >> >> if (!pe) { >> >> >> pr_err("%s: No PE found on PCI device %s\n", >> >> >> __func__, pci_name(dev)); >> >> >> - return -EINVAL; >> >> >> + return -ENOTTY; >> >> >> } >> >> >> >> >> >> + if (probe) >> >> >> + return 0; >> >> >> + >> >> >> switch (state) { >> >> >> case pcie_deassert_reset: >> >> >> eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); >> >> >> @@ -762,8 +768,8 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat >> >> >> break; >> >> >> default: >> >> >> eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED); >> >> >> - return -EINVAL; >> >> >> - }; >> >> >> + return -ENOTTY; >> >> >> + } >> >> >> >> >> >> return 0; >> >> >> } >> >> >> diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c >> >> >> index 1ef0164..3a87bfc 100644 >> >> >> --- a/drivers/misc/cxl/pci.c >> >> >> +++ b/drivers/misc/cxl/pci.c >> >> >> @@ -789,7 +789,7 @@ int cxl_reset(struct cxl *adapter) >> >> >> /* pcie_warm_reset requests a fundamental pci reset which includes a >> >> >> * PERST assert/deassert. PERST triggers a loading of the image >> >> >> * if "user" or "factory" is selected in sysfs */ >> >> >> - if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset))) { >> >> >> + if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset, 0))) { >> >> >> dev_err(&dev->dev, "cxl: pcie_warm_reset failed\n"); >> >> >> return rc; >> >> >> } >> >> >> diff --git a/drivers/misc/genwqe/card_base.c b/drivers/misc/genwqe/card_base.c >> >> >> index 4cf8f82..4871f69 100644 >> >> >> --- a/drivers/misc/genwqe/card_base.c >> >> >> +++ b/drivers/misc/genwqe/card_base.c >> >> >> @@ -782,17 +782,22 @@ static int genwqe_pci_fundamental_reset(struct pci_dev *pci_dev) >> >> >> { >> >> >> int rc; >> >> >> >> >> >> + /* Probe if the device can take the reset */ >> >> >> + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 1); >> >> >> + if (rc) >> >> >> + return rc; >> >> >> + >> >> >> /* >> >> >> * lock pci config space access from userspace, >> >> >> * save state and issue PCIe fundamental reset >> >> >> */ >> >> >> pci_cfg_access_lock(pci_dev); >> >> >> pci_save_state(pci_dev); >> >> >> - rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset); >> >> >> + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 0); >> >> >> if (!rc) { >> >> >> /* keep PCIe reset asserted for 250ms */ >> >> >> msleep(250); >> >> >> - pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset); >> >> >> + pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset, 0); >> >> >> /* Wait for 2s to reload flash and train the link */ >> >> >> msleep(2000); >> >> >> } >> >> >> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c >> >> >> index 81f06e8..8581a5f 100644 >> >> >> --- a/drivers/pci/pci.c >> >> >> +++ b/drivers/pci/pci.c >> >> >> @@ -1558,28 +1558,31 @@ EXPORT_SYMBOL(pci_disable_device); >> >> >> * pcibios_set_pcie_reset_state - set reset state for device dev >> >> >> * @dev: the PCIe device reset >> >> >> * @state: Reset state to enter into >> >> >> - * >> >> >> + * @probe: Check if the device can take the reset >> >> >> * >> >> >> * Sets the PCIe reset state for the device. This is the default >> >> >> * implementation. Architecture implementations can override this. >> >> >> */ >> >> >> int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev, >> >> >> - enum pcie_reset_state state) >> >> >> + enum pcie_reset_state state, >> >> >> + int probe) >> >> >> { >> >> >> - return -EINVAL; >> >> >> + return -ENOTTY; >> >> >> } >> >> >> >> >> >> /** >> >> >> * pci_set_pcie_reset_state - set reset state for device dev >> >> >> * @dev: the PCIe device reset >> >> >> * @state: Reset state to enter into >> >> >> - * >> >> >> + * @probe: Check if the device can take the reset >> >> >> * >> >> >> * Sets the PCI reset state for the device. >> >> >> */ >> >> >> -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) >> >> >> +int pci_set_pcie_reset_state(struct pci_dev *dev, >> >> >> + enum pcie_reset_state state, >> >> >> + int probe) >> >> >> { >> >> >> - return pcibios_set_pcie_reset_state(dev, state); >> >> >> + return pcibios_set_pcie_reset_state(dev, state, probe); >> >> >> } >> >> >> EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state); >> >> >> >> >> >> diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c >> >> >> index 9219953..89026f4 100644 >> >> >> --- a/drivers/scsi/ipr.c >> >> >> +++ b/drivers/scsi/ipr.c >> >> >> @@ -8317,7 +8317,8 @@ static int ipr_reset_start_bist(struct ipr_cmnd *ipr_cmd) >> >> >> static int ipr_reset_slot_reset_done(struct ipr_cmnd *ipr_cmd) >> >> >> { >> >> >> ENTER; >> >> >> - pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, pcie_deassert_reset); >> >> >> + pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, >> >> >> + pcie_deassert_reset, 0); >> >> >> ipr_cmd->job_step = ipr_reset_bist_done; >> >> >> ipr_reset_start_timer(ipr_cmd, IPR_WAIT_FOR_BIST_TIMEOUT); >> >> >> LEAVE; >> >> >> @@ -8339,7 +8340,7 @@ static int ipr_reset_slot_reset(struct ipr_cmnd *ipr_cmd) >> >> >> struct pci_dev *pdev = ioa_cfg->pdev; >> >> >> >> >> >> ENTER; >> >> >> - pci_set_pcie_reset_state(pdev, pcie_warm_reset); >> >> >> + pci_set_pcie_reset_state(pdev, pcie_warm_reset, 0); >> >> >> ipr_cmd->job_step = ipr_reset_slot_reset_done; >> >> >> ipr_reset_start_timer(ipr_cmd, IPR_PCI_RESET_TIMEOUT); >> >> >> LEAVE; >> >> >> diff --git a/include/linux/pci.h b/include/linux/pci.h >> >> >> index 4e1f17d..052ac63 100644 >> >> >> --- a/include/linux/pci.h >> >> >> +++ b/include/linux/pci.h >> >> >> @@ -960,7 +960,8 @@ extern unsigned int pcibios_max_latency; >> >> >> void pci_set_master(struct pci_dev *dev); >> >> >> void pci_clear_master(struct pci_dev *dev); >> >> >> >> >> >> -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state); >> >> >> +int pci_set_pcie_reset_state(struct pci_dev *dev, >> >> >> + enum pcie_reset_state state, int probe); >> >> >> int pci_set_cacheline_size(struct pci_dev *dev); >> >> >> #define HAVE_PCI_SET_MWI >> >> >> int __must_check pci_set_mwi(struct pci_dev *dev); >> >> >> @@ -1648,7 +1649,7 @@ extern unsigned long pci_hotplug_mem_size; >> >> >> void pcibios_disable_device(struct pci_dev *dev); >> >> >> void pcibios_set_master(struct pci_dev *dev); >> >> >> int pcibios_set_pcie_reset_state(struct pci_dev *dev, >> >> >> - enum pcie_reset_state state); >> >> >> + enum pcie_reset_state state, int probe); >> >> >> int pcibios_add_device(struct pci_dev *dev); >> >> >> void pcibios_release_device(struct pci_dev *dev); >> >> >> void pcibios_penalize_isa_irq(int irq, int active); >> >> > >> >> > >> >> > >> >> >> > >> > >> > >> > > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 2015-03-23 at 17:07 -0300, cascardo@linux.vnet.ibm.com wrote: > > I agree with you here. I think the bigger issue is that we are not > making sure VFIO is secure, allowing functions to be assigned > separately to different guests, even when we cannot guarantee we can > safely reset a single function, and also ignoring the possibility of > internal communication between functions. This second problem is real, > since some adapters will allow firmware to be loaded or reset, which > will affect other functions. We do ... on power. We don't create per-function PEs for that specific reason. Yes it does prevent individual ports of network adapters from being assigned to different guests but the HW cannot be trusted. We might add ways to "relax" this for cases where the user somewhat knows what he is doing, but the problem of the reset will remain. > We need to either have in written that this is acceptable and that > higher layers should take care of these possibilities, if they care > about them, or we need to fix this, by making VFIO only accept a whole > group of functions to be assigned to a guest, which will allow the > problem described by Gavin to be properly handled, by using slot reset > functions, or another way of grouping devices that may be specific to > the platform. > Does it make sense? > > Cascardo. > > > > >> >> diff --git a/arch/powerpc/kernel/eeh.c > b/arch/powerpc/kernel/eeh.c > > > >> >> index daa68a1..cd85c18 100644 > > > >> >> --- a/arch/powerpc/kernel/eeh.c > > > >> >> +++ b/arch/powerpc/kernel/eeh.c > > > >> >> @@ -726,11 +726,14 @@ static void > *eeh_restore_dev_state(void *data, void *userdata) > > > >> >> * pcibios_set_pcie_slot_reset - Set PCI-E reset state > > > >> >> * @dev: pci device struct > > > >> >> * @state: reset state to enter > > > >> >> + * @probe: check if the device can take the reset > > > >> >> * > > > >> >> * Return value: > > > >> >> * 0 if success > > > >> >> */ > > > >> >> -int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum > pcie_reset_state state) > > > >> >> +int pcibios_set_pcie_reset_state(struct pci_dev *dev, > > > >> >> + enum pcie_reset_state state, > > > >> >> + int probe) > > > >> >> { > > > >> >> struct eeh_dev *edev = pci_dev_to_eeh_dev(dev); > > > >> >> struct eeh_pe *pe = eeh_dev_to_pe(edev); > > > >> >> @@ -738,9 +741,12 @@ int pcibios_set_pcie_reset_state(struct > pci_dev *dev, enum pcie_reset_state stat > > > >> >> if (!pe) { > > > >> >> pr_err("%s: No PE found on PCI device %s\n", > > > >> >> __func__, pci_name(dev)); > > > >> >> - return -EINVAL; > > > >> >> + return -ENOTTY; > > > >> >> } > > > >> >> > > > >> >> + if (probe) > > > >> >> + return 0; > > > >> >> + > > > >> >> switch (state) { > > > >> >> case pcie_deassert_reset: > > > >> >> eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); > > > >> >> @@ -762,8 +768,8 @@ int pcibios_set_pcie_reset_state(struct > pci_dev *dev, enum pcie_reset_state stat > > > >> >> break; > > > >> >> default: > > > >> >> eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED); > > > >> >> - return -EINVAL; > > > >> >> - }; > > > >> >> + return -ENOTTY; > > > >> >> + } > > > >> >> > > > >> >> return 0; > > > >> >> } > > > >> >> diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c > > > >> >> index 1ef0164..3a87bfc 100644 > > > >> >> --- a/drivers/misc/cxl/pci.c > > > >> >> +++ b/drivers/misc/cxl/pci.c > > > >> >> @@ -789,7 +789,7 @@ int cxl_reset(struct cxl *adapter) > > > >> >> /* pcie_warm_reset requests a fundamental pci reset > which includes a > > > >> >> * PERST assert/deassert. PERST triggers a loading of > the image > > > >> >> * if "user" or "factory" is selected in sysfs */ > > > >> >> - if ((rc = pci_set_pcie_reset_state(dev, > pcie_warm_reset))) { > > > >> >> + if ((rc = pci_set_pcie_reset_state(dev, > pcie_warm_reset, 0))) { > > > >> >> dev_err(&dev->dev, "cxl: pcie_warm_reset > failed\n"); > > > >> >> return rc; > > > >> >> } > > > >> >> diff --git a/drivers/misc/genwqe/card_base.c > b/drivers/misc/genwqe/card_base.c > > > >> >> index 4cf8f82..4871f69 100644 > > > >> >> --- a/drivers/misc/genwqe/card_base.c > > > >> >> +++ b/drivers/misc/genwqe/card_base.c > > > >> >> @@ -782,17 +782,22 @@ static int > genwqe_pci_fundamental_reset(struct pci_dev *pci_dev) > > > >> >> { > > > >> >> int rc; > > > >> >> > > > >> >> + /* Probe if the device can take the reset */ > > > >> >> + rc = pci_set_pcie_reset_state(pci_dev, > pcie_warm_reset, 1); > > > >> >> + if (rc) > > > >> >> + return rc; > > > >> >> + > > > >> >> /* > > > >> >> * lock pci config space access from userspace, > > > >> >> * save state and issue PCIe fundamental reset > > > >> >> */ > > > >> >> pci_cfg_access_lock(pci_dev); > > > >> >> pci_save_state(pci_dev); > > > >> >> - rc = pci_set_pcie_reset_state(pci_dev, > pcie_warm_reset); > > > >> >> + rc = pci_set_pcie_reset_state(pci_dev, > pcie_warm_reset, 0); > > > >> >> if (!rc) { > > > >> >> /* keep PCIe reset asserted for 250ms */ > > > >> >> msleep(250); > > > >> >> - pci_set_pcie_reset_state(pci_dev, > pcie_deassert_reset); > > > >> >> + pci_set_pcie_reset_state(pci_dev, > pcie_deassert_reset, 0); > > > >> >> /* Wait for 2s to reload flash and train the > link */ > > > >> >> msleep(2000); > > > >> >> } > > > >> >> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > >> >> index 81f06e8..8581a5f 100644 > > > >> >> --- a/drivers/pci/pci.c > > > >> >> +++ b/drivers/pci/pci.c > > > >> >> @@ -1558,28 +1558,31 @@ EXPORT_SYMBOL(pci_disable_device); > > > >> >> * pcibios_set_pcie_reset_state - set reset state for > device dev > > > >> >> * @dev: the PCIe device reset > > > >> >> * @state: Reset state to enter into > > > >> >> - * > > > >> >> + * @probe: Check if the device can take the reset > > > >> >> * > > > >> >> * Sets the PCIe reset state for the device. This is the > default > > > >> >> * implementation. Architecture implementations can > override this. > > > >> >> */ > > > >> >> int __weak pcibios_set_pcie_reset_state(struct pci_dev > *dev, > > > >> >> - enum pcie_reset_state > state) > > > >> >> + enum pcie_reset_state > state, > > > >> >> + int probe) > > > >> >> { > > > >> >> - return -EINVAL; > > > >> >> + return -ENOTTY; > > > >> >> } > > > >> >> > > > >> >> /** > > > >> >> * pci_set_pcie_reset_state - set reset state for device > dev > > > >> >> * @dev: the PCIe device reset > > > >> >> * @state: Reset state to enter into > > > >> >> - * > > > >> >> + * @probe: Check if the device can take the reset > > > >> >> * > > > >> >> * Sets the PCI reset state for the device. > > > >> >> */ > > > >> >> -int pci_set_pcie_reset_state(struct pci_dev *dev, enum > pcie_reset_state state) > > > >> >> +int pci_set_pcie_reset_state(struct pci_dev *dev, > > > >> >> + enum pcie_reset_state state, > > > >> >> + int probe) > > > >> >> { > > > >> >> - return pcibios_set_pcie_reset_state(dev, state); > > > >> >> + return pcibios_set_pcie_reset_state(dev, state, > probe); > > > >> >> } > > > >> >> EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state); > > > >> >> > > > >> >> diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c > > > >> >> index 9219953..89026f4 100644 > > > >> >> --- a/drivers/scsi/ipr.c > > > >> >> +++ b/drivers/scsi/ipr.c > > > >> >> @@ -8317,7 +8317,8 @@ static int ipr_reset_start_bist(struct > ipr_cmnd *ipr_cmd) > > > >> >> static int ipr_reset_slot_reset_done(struct ipr_cmnd > *ipr_cmd) > > > >> >> { > > > >> >> ENTER; > > > >> >> - pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, > pcie_deassert_reset); > > > >> >> + pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, > > > >> >> + pcie_deassert_reset, 0); > > > >> >> ipr_cmd->job_step = ipr_reset_bist_done; > > > >> >> ipr_reset_start_timer(ipr_cmd, > IPR_WAIT_FOR_BIST_TIMEOUT); > > > >> >> LEAVE; > > > >> >> @@ -8339,7 +8340,7 @@ static int ipr_reset_slot_reset(struct > ipr_cmnd *ipr_cmd) > > > >> >> struct pci_dev *pdev = ioa_cfg->pdev; > > > >> >> > > > >> >> ENTER; > > > >> >> - pci_set_pcie_reset_state(pdev, pcie_warm_reset); > > > >> >> + pci_set_pcie_reset_state(pdev, pcie_warm_reset, 0); > > > >> >> ipr_cmd->job_step = ipr_reset_slot_reset_done; > > > >> >> ipr_reset_start_timer(ipr_cmd, IPR_PCI_RESET_TIMEOUT); > > > >> >> LEAVE; > > > >> >> diff --git a/include/linux/pci.h b/include/linux/pci.h > > > >> >> index 4e1f17d..052ac63 100644 > > > >> >> --- a/include/linux/pci.h > > > >> >> +++ b/include/linux/pci.h > > > >> >> @@ -960,7 +960,8 @@ extern unsigned int pcibios_max_latency; > > > >> >> void pci_set_master(struct pci_dev *dev); > > > >> >> void pci_clear_master(struct pci_dev *dev); > > > >> >> > > > >> >> -int pci_set_pcie_reset_state(struct pci_dev *dev, enum > pcie_reset_state state); > > > >> >> +int pci_set_pcie_reset_state(struct pci_dev *dev, > > > >> >> + enum pcie_reset_state state, int > probe); > > > >> >> int pci_set_cacheline_size(struct pci_dev *dev); > > > >> >> #define HAVE_PCI_SET_MWI > > > >> >> int __must_check pci_set_mwi(struct pci_dev *dev); > > > >> >> @@ -1648,7 +1649,7 @@ extern unsigned long > pci_hotplug_mem_size; > > > >> >> void pcibios_disable_device(struct pci_dev *dev); > > > >> >> void pcibios_set_master(struct pci_dev *dev); > > > >> >> int pcibios_set_pcie_reset_state(struct pci_dev *dev, > > > >> >> - enum pcie_reset_state state); > > > >> >> + enum pcie_reset_state state, > int probe); > > > >> >> int pcibios_add_device(struct pci_dev *dev); > > > >> >> void pcibios_release_device(struct pci_dev *dev); > > > >> >> void pcibios_penalize_isa_irq(int irq, int active); > > > >> > > > > >> > > > > >> > > > > >> > > > > > > > > > > > > > > > > > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 2015-03-23 at 15:08 -0600, Alex Williamson wrote: > > I don't know what you're doing on POWER, I thought groups were > equivalent to PEs, but on x86 we learn about isolation of PCI functions > by standard PCI properties. Devices need to tell us that they're > isolated via ACS capabilities (or quirks, with vendor approval). > Otherwise we assume there is no isolation and multi-function devices > will be grouped together, preventing the individual functions from being > assigned to separate userspace instances. VFIO does not ignore the > problem of internal communication between functions, it uses ACS... at > least on most platforms. POWER doesn't allow functions in different PEs today (mostly for a different reason which is the problem we have with MMIO assignment to different PEs, though we are working on ways to fix that in the future in which case we might start using ACS). There's still a potential issue with LSIs though, I haven't looked how you handle it on x86. > Firmware shared between functions is an unsolvable problem outside of > restricting device assignment only to SR-IOV virtual functions. We > cannot know the programming method to block firmware updates of an > assigned device nor can we control which functions share the firmware. > If you're worried about this level of attack against the hardware, use > VFs exclusively. You cannot trust HW :-) > If you're unsatisfied with the grouping of devices on your platform, > this is entirely within your control since VFIO relies on IOMMU groups, > which are managed via the platform IOMMU driver. If your IOMMU driver > is arbitrarily splitting each PCI function into a separate group without > testing the isolation, that's a problem with IOMMU groups on your > platform. If you would like to add a reset requirement to a group, you > have the ability to do that. On x86, I expect this would be far too > restrictive. That means that you cannot recover devices that don't support FLR... > VFIO also knows how to do bus and slot resets, the pci_reset_bus() and > pci_reset_slot() interfaces were added by me with vfio-pci as the first > user. Resets are generally handled as best effort though and this is > sometimes a property of a device that might make it unsuitable for > device assignment. Or unsuitable as a multi-function split assignment, we can still give the whole slot to the guest. > The fact that you're implying above that the devices covered by the > device specific reset proposed in this series can be assigned separately > makes ignoring the scope of pci_reset_function() all the more wrong. If > you want to change grouping on POWER to require that a group can be > reset, that's an IOMMU driver issue. If you want to make a change to > VFIO to require an opt-in/out of allowing access to groups without a > reset, then propose something. Just please don't ignore the semantics > of existing functions because it's a quicker and easier hack than doing > it correctly. Thanks, The IOMMU driver unfortunately cannot know whether the devices support a good reset granularity without quirks ... Oh well. It's a mess, thanks for Intel for not making FLR mandatory since PCI 1.0 .... :-) Cheers, Ben. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c index daa68a1..cd85c18 100644 --- a/arch/powerpc/kernel/eeh.c +++ b/arch/powerpc/kernel/eeh.c @@ -726,11 +726,14 @@ static void *eeh_restore_dev_state(void *data, void *userdata) * pcibios_set_pcie_slot_reset - Set PCI-E reset state * @dev: pci device struct * @state: reset state to enter + * @probe: check if the device can take the reset * * Return value: * 0 if success */ -int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) +int pcibios_set_pcie_reset_state(struct pci_dev *dev, + enum pcie_reset_state state, + int probe) { struct eeh_dev *edev = pci_dev_to_eeh_dev(dev); struct eeh_pe *pe = eeh_dev_to_pe(edev); @@ -738,9 +741,12 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat if (!pe) { pr_err("%s: No PE found on PCI device %s\n", __func__, pci_name(dev)); - return -EINVAL; + return -ENOTTY; } + if (probe) + return 0; + switch (state) { case pcie_deassert_reset: eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); @@ -762,8 +768,8 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state stat break; default: eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED); - return -EINVAL; - }; + return -ENOTTY; + } return 0; } diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c index 1ef0164..3a87bfc 100644 --- a/drivers/misc/cxl/pci.c +++ b/drivers/misc/cxl/pci.c @@ -789,7 +789,7 @@ int cxl_reset(struct cxl *adapter) /* pcie_warm_reset requests a fundamental pci reset which includes a * PERST assert/deassert. PERST triggers a loading of the image * if "user" or "factory" is selected in sysfs */ - if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset))) { + if ((rc = pci_set_pcie_reset_state(dev, pcie_warm_reset, 0))) { dev_err(&dev->dev, "cxl: pcie_warm_reset failed\n"); return rc; } diff --git a/drivers/misc/genwqe/card_base.c b/drivers/misc/genwqe/card_base.c index 4cf8f82..4871f69 100644 --- a/drivers/misc/genwqe/card_base.c +++ b/drivers/misc/genwqe/card_base.c @@ -782,17 +782,22 @@ static int genwqe_pci_fundamental_reset(struct pci_dev *pci_dev) { int rc; + /* Probe if the device can take the reset */ + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 1); + if (rc) + return rc; + /* * lock pci config space access from userspace, * save state and issue PCIe fundamental reset */ pci_cfg_access_lock(pci_dev); pci_save_state(pci_dev); - rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset); + rc = pci_set_pcie_reset_state(pci_dev, pcie_warm_reset, 0); if (!rc) { /* keep PCIe reset asserted for 250ms */ msleep(250); - pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset); + pci_set_pcie_reset_state(pci_dev, pcie_deassert_reset, 0); /* Wait for 2s to reload flash and train the link */ msleep(2000); } diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 81f06e8..8581a5f 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1558,28 +1558,31 @@ EXPORT_SYMBOL(pci_disable_device); * pcibios_set_pcie_reset_state - set reset state for device dev * @dev: the PCIe device reset * @state: Reset state to enter into - * + * @probe: Check if the device can take the reset * * Sets the PCIe reset state for the device. This is the default * implementation. Architecture implementations can override this. */ int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev, - enum pcie_reset_state state) + enum pcie_reset_state state, + int probe) { - return -EINVAL; + return -ENOTTY; } /** * pci_set_pcie_reset_state - set reset state for device dev * @dev: the PCIe device reset * @state: Reset state to enter into - * + * @probe: Check if the device can take the reset * * Sets the PCI reset state for the device. */ -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) +int pci_set_pcie_reset_state(struct pci_dev *dev, + enum pcie_reset_state state, + int probe) { - return pcibios_set_pcie_reset_state(dev, state); + return pcibios_set_pcie_reset_state(dev, state, probe); } EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state); diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c index 9219953..89026f4 100644 --- a/drivers/scsi/ipr.c +++ b/drivers/scsi/ipr.c @@ -8317,7 +8317,8 @@ static int ipr_reset_start_bist(struct ipr_cmnd *ipr_cmd) static int ipr_reset_slot_reset_done(struct ipr_cmnd *ipr_cmd) { ENTER; - pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, pcie_deassert_reset); + pci_set_pcie_reset_state(ipr_cmd->ioa_cfg->pdev, + pcie_deassert_reset, 0); ipr_cmd->job_step = ipr_reset_bist_done; ipr_reset_start_timer(ipr_cmd, IPR_WAIT_FOR_BIST_TIMEOUT); LEAVE; @@ -8339,7 +8340,7 @@ static int ipr_reset_slot_reset(struct ipr_cmnd *ipr_cmd) struct pci_dev *pdev = ioa_cfg->pdev; ENTER; - pci_set_pcie_reset_state(pdev, pcie_warm_reset); + pci_set_pcie_reset_state(pdev, pcie_warm_reset, 0); ipr_cmd->job_step = ipr_reset_slot_reset_done; ipr_reset_start_timer(ipr_cmd, IPR_PCI_RESET_TIMEOUT); LEAVE; diff --git a/include/linux/pci.h b/include/linux/pci.h index 4e1f17d..052ac63 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -960,7 +960,8 @@ extern unsigned int pcibios_max_latency; void pci_set_master(struct pci_dev *dev); void pci_clear_master(struct pci_dev *dev); -int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state); +int pci_set_pcie_reset_state(struct pci_dev *dev, + enum pcie_reset_state state, int probe); int pci_set_cacheline_size(struct pci_dev *dev); #define HAVE_PCI_SET_MWI int __must_check pci_set_mwi(struct pci_dev *dev); @@ -1648,7 +1649,7 @@ extern unsigned long pci_hotplug_mem_size; void pcibios_disable_device(struct pci_dev *dev); void pcibios_set_master(struct pci_dev *dev); int pcibios_set_pcie_reset_state(struct pci_dev *dev, - enum pcie_reset_state state); + enum pcie_reset_state state, int probe); int pcibios_add_device(struct pci_dev *dev); void pcibios_release_device(struct pci_dev *dev); void pcibios_penalize_isa_irq(int irq, int active);
The patch adds one more parameter ("probe") to pci_set_pcie_reset_state(), which allows to check if one particular PCI device can be resetted by the function. The function will be reused to support PCI device specific methods maintained in pci_dev_reset_methods[] in subsequent patch. Cc: Brian King <brking@us.ibm.com> Cc: Frank Haverkamp <haver@linux.vnet.ibm.com> Cc: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> --- v3: Fix arguments of pci_set_pcie_reset_state() in cxl driver v2: Reimplemented based on pci_set_pcie_reset_state() --- arch/powerpc/kernel/eeh.c | 14 ++++++++++---- drivers/misc/cxl/pci.c | 2 +- drivers/misc/genwqe/card_base.c | 9 +++++++-- drivers/pci/pci.c | 15 +++++++++------ drivers/scsi/ipr.c | 5 +++-- include/linux/pci.h | 5 +++-- 6 files changed, 33 insertions(+), 17 deletions(-)