| Message ID | 1435649834-3148-1-git-send-email-weiyang@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Tue, Jun 30, 2015 at 03:37:14PM +0800, Wei Yang wrote: > VF BARs are RO zero, so updating VF BARs will not take any effect. > See the SR-IOV spec r1.1, sec 3.4.1.11. > > Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com> > --- > drivers/pci/setup-res.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c > index 232f925..334b394 100644 > --- a/drivers/pci/setup-res.c > +++ b/drivers/pci/setup-res.c > @@ -37,6 +37,13 @@ void pci_update_resource(struct pci_dev *dev, int resno) > struct resource *res = dev->resource + resno; > > /* > + * Per SRIOV SPEC 3.4.1.11, VF BARs are RO zero. > + * If this is a VF, just return. > + */ > + if (dev->is_virtfn) > + return; Does this fix a problem? Are you seeing the "BAR %d: error updating" message? I wouldn't think we would even call pci_update_resource() for VFs, except for pci_restore_bars(). Maybe we should check there? If the PCI core is assigning space directly to VF BARs and trying to update them, I'd like to know about that rather than silently ignoring it. > + > + /* > * Ignore resources for unimplemented BARs and unused resource slots > * for 64 bit BARs. > */ > -- > 1.7.9.5 > -- 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 Tue, Jul 14, 2015 at 05:15:11PM -0500, Bjorn Helgaas wrote: >On Tue, Jun 30, 2015 at 03:37:14PM +0800, Wei Yang wrote: >> VF BARs are RO zero, so updating VF BARs will not take any effect. >> See the SR-IOV spec r1.1, sec 3.4.1.11. >> >> Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com> >> --- >> drivers/pci/setup-res.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c >> index 232f925..334b394 100644 >> --- a/drivers/pci/setup-res.c >> +++ b/drivers/pci/setup-res.c >> @@ -37,6 +37,13 @@ void pci_update_resource(struct pci_dev *dev, int resno) >> struct resource *res = dev->resource + resno; >> >> /* >> + * Per SRIOV SPEC 3.4.1.11, VF BARs are RO zero. >> + * If this is a VF, just return. >> + */ >> + if (dev->is_virtfn) >> + return; > >Does this fix a problem? Are you seeing the "BAR %d: error updating" >message? > Yes, I see the "error updating" message when doing vfio pass through. >I wouldn't think we would even call pci_update_resource() for VFs, except >for pci_restore_bars(). Maybe we should check there? > This happens after commit <6eb7018705de> ("vfio-pci: Move idle devices to D3hot power state"). When do vfio, it will set the power state, and which in turn update the BAR. Hmm... yes, maybe the pci_restore_bars() is a good place to check. >If the PCI core is assigning space directly to VF BARs and trying to update >them, I'd like to know about that rather than silently ignoring it. > Ok, so I would add a warning at this place. >> + >> + /* >> * Ignore resources for unimplemented BARs and unused resource slots >> * for 64 bit BARs. >> */ >> -- >> 1.7.9.5 >>
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c index 232f925..334b394 100644 --- a/drivers/pci/setup-res.c +++ b/drivers/pci/setup-res.c @@ -37,6 +37,13 @@ void pci_update_resource(struct pci_dev *dev, int resno) struct resource *res = dev->resource + resno; /* + * Per SRIOV SPEC 3.4.1.11, VF BARs are RO zero. + * If this is a VF, just return. + */ + if (dev->is_virtfn) + return; + + /* * Ignore resources for unimplemented BARs and unused resource slots * for 64 bit BARs. */
VF BARs are RO zero, so updating VF BARs will not take any effect. See the SR-IOV spec r1.1, sec 3.4.1.11. Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com> --- drivers/pci/setup-res.c | 7 +++++++ 1 file changed, 7 insertions(+)