| Message ID | 20200601162934.842648-1-jusual@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | hw/pci/pcie: Move hot plug capability check to pre_plug callback | expand |
On Mon, Jun 01, 2020 at 06:29:34PM +0200, Julia Suvorova wrote: > Check for hot plug capability earlier to avoid removing devices attached > during the initialization process. > > Run qemu with an unattached drive: > -drive file=$FILE,if=none,id=drive0 \ > -device pcie-root-port,id=rp0,slot=3,bus=pcie.0,hotplug=off > Hotplug a block device: > device_add virtio-blk-pci,id=blk0,drive=drive0,bus=rp0 > If hotplug fails on plug_cb, drive0 will be deleted. > > Signed-off-by: Julia Suvorova <jusual@redhat.com> Fixes: 0501e1aa1d32a6 ("hw/pci/pcie: Forbid hot-plug if it's disabled on the slot") correct? > --- > Hard to say if it's a bug or generally acceptable behaviour, but seems like > hotplug_handler_plug should never fail. > > hw/pci/pcie.c | 19 +++++++++++-------- > 1 file changed, 11 insertions(+), 8 deletions(-) > > diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c > index f50e10b8fb..5b9c022d91 100644 > --- a/hw/pci/pcie.c > +++ b/hw/pci/pcie.c > @@ -407,6 +407,17 @@ static void pcie_cap_slot_plug_common(PCIDevice *hotplug_dev, DeviceState *dev, > void pcie_cap_slot_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, > Error **errp) > { > + PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); > + uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; > + uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); > + > + /* Check if hot-plug is disabled on the slot */ > + if (dev->hotplugged && (sltcap & PCI_EXP_SLTCAP_HPC) == 0) { > + error_setg(errp, "Hot-plug failed: unsupported by the port device '%s'", > + DEVICE(hotplug_pdev)->id); > + return; > + } > + > pcie_cap_slot_plug_common(PCI_DEVICE(hotplug_dev), dev, errp); > } > > @@ -415,7 +426,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, > { > PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); > uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; > - uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); > PCIDevice *pci_dev = PCI_DEVICE(dev); > > /* Don't send event when device is enabled during qemu machine creation: > @@ -431,13 +441,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, > return; > } > > - /* Check if hot-plug is disabled on the slot */ > - if ((sltcap & PCI_EXP_SLTCAP_HPC) == 0) { > - error_setg(errp, "Hot-plug failed: unsupported by the port device '%s'", > - DEVICE(hotplug_pdev)->id); > - return; > - } > - > /* To enable multifunction hot-plug, we just ensure the function > * 0 added last. When function 0 is added, we set the sltsta and > * inform OS via event notification. > -- > 2.25.4
On Tue, Jun 2, 2020 at 5:54 AM Michael S. Tsirkin <mst@redhat.com> wrote: > > On Mon, Jun 01, 2020 at 06:29:34PM +0200, Julia Suvorova wrote: > > Check for hot plug capability earlier to avoid removing devices attached > > during the initialization process. > > > > Run qemu with an unattached drive: > > -drive file=$FILE,if=none,id=drive0 \ > > -device pcie-root-port,id=rp0,slot=3,bus=pcie.0,hotplug=off > > Hotplug a block device: > > device_add virtio-blk-pci,id=blk0,drive=drive0,bus=rp0 > > If hotplug fails on plug_cb, drive0 will be deleted. > > > > Signed-off-by: Julia Suvorova <jusual@redhat.com> > > > Fixes: 0501e1aa1d32a6 ("hw/pci/pcie: Forbid hot-plug if it's disabled on the slot") > > correct? Yes. > > --- > > Hard to say if it's a bug or generally acceptable behaviour, but seems like > > hotplug_handler_plug should never fail. > > > > hw/pci/pcie.c | 19 +++++++++++-------- > > 1 file changed, 11 insertions(+), 8 deletions(-) > > > > diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c > > index f50e10b8fb..5b9c022d91 100644 > > --- a/hw/pci/pcie.c > > +++ b/hw/pci/pcie.c > > @@ -407,6 +407,17 @@ static void pcie_cap_slot_plug_common(PCIDevice *hotplug_dev, DeviceState *dev, > > void pcie_cap_slot_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, > > Error **errp) > > { > > + PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); > > + uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; > > + uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); > > + > > + /* Check if hot-plug is disabled on the slot */ > > + if (dev->hotplugged && (sltcap & PCI_EXP_SLTCAP_HPC) == 0) { > > + error_setg(errp, "Hot-plug failed: unsupported by the port device '%s'", > > + DEVICE(hotplug_pdev)->id); > > + return; > > + } > > + > > pcie_cap_slot_plug_common(PCI_DEVICE(hotplug_dev), dev, errp); > > } > > > > @@ -415,7 +426,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, > > { > > PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); > > uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; > > - uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); > > PCIDevice *pci_dev = PCI_DEVICE(dev); > > > > /* Don't send event when device is enabled during qemu machine creation: > > @@ -431,13 +441,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, > > return; > > } > > > > - /* Check if hot-plug is disabled on the slot */ > > - if ((sltcap & PCI_EXP_SLTCAP_HPC) == 0) { > > - error_setg(errp, "Hot-plug failed: unsupported by the port device '%s'", > > - DEVICE(hotplug_pdev)->id); > > - return; > > - } > > - > > /* To enable multifunction hot-plug, we just ensure the function > > * 0 added last. When function 0 is added, we set the sltsta and > > * inform OS via event notification. > > -- > > 2.25.4 >
On Mon, 1 Jun 2020 18:29:34 +0200 Julia Suvorova <jusual@redhat.com> wrote: > Check for hot plug capability earlier to avoid removing devices attached > during the initialization process. > > Run qemu with an unattached drive: > -drive file=$FILE,if=none,id=drive0 \ > -device pcie-root-port,id=rp0,slot=3,bus=pcie.0,hotplug=off > Hotplug a block device: > device_add virtio-blk-pci,id=blk0,drive=drive0,bus=rp0 > If hotplug fails on plug_cb, drive0 will be deleted. > > Signed-off-by: Julia Suvorova <jusual@redhat.com> > --- > Hard to say if it's a bug or generally acceptable behaviour, but seems like > hotplug_handler_plug should never fail. _unplug shouldn't fail the rest are allowed to, but it's hard to unwind intialization cleanly to _plug stage so if it's possible to do checks at _pre_plug time (i.e. before device's realize() is called) we should do so. Acked-by: Igor Mammedov <imammedo@redhat.com> > > hw/pci/pcie.c | 19 +++++++++++-------- > 1 file changed, 11 insertions(+), 8 deletions(-) > > diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c > index f50e10b8fb..5b9c022d91 100644 > --- a/hw/pci/pcie.c > +++ b/hw/pci/pcie.c > @@ -407,6 +407,17 @@ static void pcie_cap_slot_plug_common(PCIDevice *hotplug_dev, DeviceState *dev, > void pcie_cap_slot_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, > Error **errp) > { > + PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); > + uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; > + uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); > + > + /* Check if hot-plug is disabled on the slot */ > + if (dev->hotplugged && (sltcap & PCI_EXP_SLTCAP_HPC) == 0) { > + error_setg(errp, "Hot-plug failed: unsupported by the port device '%s'", > + DEVICE(hotplug_pdev)->id); > + return; > + } > + > pcie_cap_slot_plug_common(PCI_DEVICE(hotplug_dev), dev, errp); > } > > @@ -415,7 +426,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, > { > PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); > uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; > - uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); > PCIDevice *pci_dev = PCI_DEVICE(dev); > > /* Don't send event when device is enabled during qemu machine creation: > @@ -431,13 +441,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, > return; > } > > - /* Check if hot-plug is disabled on the slot */ > - if ((sltcap & PCI_EXP_SLTCAP_HPC) == 0) { > - error_setg(errp, "Hot-plug failed: unsupported by the port device '%s'", > - DEVICE(hotplug_pdev)->id); > - return; > - } > - > /* To enable multifunction hot-plug, we just ensure the function > * 0 added last. When function 0 is added, we set the sltsta and > * inform OS via event notification.
On Thu, Jun 04, 2020 at 12:57:55PM +0200, Igor Mammedov wrote: > On Mon, 1 Jun 2020 18:29:34 +0200 > Julia Suvorova <jusual@redhat.com> wrote: > > > Check for hot plug capability earlier to avoid removing devices attached > > during the initialization process. > > > > Run qemu with an unattached drive: > > -drive file=$FILE,if=none,id=drive0 \ > > -device pcie-root-port,id=rp0,slot=3,bus=pcie.0,hotplug=off > > Hotplug a block device: > > device_add virtio-blk-pci,id=blk0,drive=drive0,bus=rp0 > > If hotplug fails on plug_cb, drive0 will be deleted. > > > > Signed-off-by: Julia Suvorova <jusual@redhat.com> > > --- > > Hard to say if it's a bug or generally acceptable behaviour, but seems like > > hotplug_handler_plug should never fail. > > _unplug shouldn't fail the rest are allowed to, but it's hard to unwind > intialization cleanly to _plug stage so if it's possible to do checks > at _pre_plug time (i.e. before device's realize() is called) we should do so. > > Acked-by: Igor Mammedov <imammedo@redhat.com> Makes sense. Julia could you repost with a tweaked commit log and I'll apply. Thanks! > > > > hw/pci/pcie.c | 19 +++++++++++-------- > > 1 file changed, 11 insertions(+), 8 deletions(-) > > > > diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c > > index f50e10b8fb..5b9c022d91 100644 > > --- a/hw/pci/pcie.c > > +++ b/hw/pci/pcie.c > > @@ -407,6 +407,17 @@ static void pcie_cap_slot_plug_common(PCIDevice *hotplug_dev, DeviceState *dev, > > void pcie_cap_slot_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, > > Error **errp) > > { > > + PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); > > + uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; > > + uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); > > + > > + /* Check if hot-plug is disabled on the slot */ > > + if (dev->hotplugged && (sltcap & PCI_EXP_SLTCAP_HPC) == 0) { > > + error_setg(errp, "Hot-plug failed: unsupported by the port device '%s'", > > + DEVICE(hotplug_pdev)->id); > > + return; > > + } > > + > > pcie_cap_slot_plug_common(PCI_DEVICE(hotplug_dev), dev, errp); > > } > > > > @@ -415,7 +426,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, > > { > > PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); > > uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; > > - uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); > > PCIDevice *pci_dev = PCI_DEVICE(dev); > > > > /* Don't send event when device is enabled during qemu machine creation: > > @@ -431,13 +441,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, > > return; > > } > > > > - /* Check if hot-plug is disabled on the slot */ > > - if ((sltcap & PCI_EXP_SLTCAP_HPC) == 0) { > > - error_setg(errp, "Hot-plug failed: unsupported by the port device '%s'", > > - DEVICE(hotplug_pdev)->id); > > - return; > > - } > > - > > /* To enable multifunction hot-plug, we just ensure the function > > * 0 added last. When function 0 is added, we set the sltsta and > > * inform OS via event notification.
diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c index f50e10b8fb..5b9c022d91 100644 --- a/hw/pci/pcie.c +++ b/hw/pci/pcie.c @@ -407,6 +407,17 @@ static void pcie_cap_slot_plug_common(PCIDevice *hotplug_dev, DeviceState *dev, void pcie_cap_slot_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, Error **errp) { + PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); + uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; + uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); + + /* Check if hot-plug is disabled on the slot */ + if (dev->hotplugged && (sltcap & PCI_EXP_SLTCAP_HPC) == 0) { + error_setg(errp, "Hot-plug failed: unsupported by the port device '%s'", + DEVICE(hotplug_pdev)->id); + return; + } + pcie_cap_slot_plug_common(PCI_DEVICE(hotplug_dev), dev, errp); } @@ -415,7 +426,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, { PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev); uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap; - uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP); PCIDevice *pci_dev = PCI_DEVICE(dev); /* Don't send event when device is enabled during qemu machine creation: @@ -431,13 +441,6 @@ void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, return; } - /* Check if hot-plug is disabled on the slot */ - if ((sltcap & PCI_EXP_SLTCAP_HPC) == 0) { - error_setg(errp, "Hot-plug failed: unsupported by the port device '%s'", - DEVICE(hotplug_pdev)->id); - return; - } - /* To enable multifunction hot-plug, we just ensure the function * 0 added last. When function 0 is added, we set the sltsta and * inform OS via event notification.
Check for hot plug capability earlier to avoid removing devices attached during the initialization process. Run qemu with an unattached drive: -drive file=$FILE,if=none,id=drive0 \ -device pcie-root-port,id=rp0,slot=3,bus=pcie.0,hotplug=off Hotplug a block device: device_add virtio-blk-pci,id=blk0,drive=drive0,bus=rp0 If hotplug fails on plug_cb, drive0 will be deleted. Signed-off-by: Julia Suvorova <jusual@redhat.com> --- Hard to say if it's a bug or generally acceptable behaviour, but seems like hotplug_handler_plug should never fail. hw/pci/pcie.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-)