| Message ID | 20241230161054.3674-2-tomitamoeko@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] vfio/pci: update igd matching conditions | expand |
On Tue, 31 Dec 2024 00:10:54 +0800 Tomita Moeko <tomitamoeko@gmail.com> wrote: > igd device can either expose as a VGA controller or display controller > depending on whether it is configured as the primary display device in > BIOS. In both cases, the OpRegion may be present. Also checks if the > device is at bdf 00:02.0 to avoid setting up igd-specific regions on > Intel discrete GPUs. > > Signed-off-by: Tomita Moeko <tomitamoeko@gmail.com> > --- > Changelog: > v2: > Fix misuse of pci_get_domain_bus_and_slot(), now only compares bdf > without touching device reference count. > Link: https://lore.kernel.org/all/20241229155140.7434-1-tomitamoeko@gmail.com/ > > drivers/vfio/pci/vfio_pci.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c > index e727941f589d..906a1db46d15 100644 > --- a/drivers/vfio/pci/vfio_pci.c > +++ b/drivers/vfio/pci/vfio_pci.c > @@ -111,9 +111,11 @@ static int vfio_pci_open_device(struct vfio_device *core_vdev) > if (ret) > return ret; > > - if (vfio_pci_is_vga(pdev) && > - pdev->vendor == PCI_VENDOR_ID_INTEL && > - IS_ENABLED(CONFIG_VFIO_PCI_IGD)) { > + if (IS_ENABLED(CONFIG_VFIO_PCI_IGD) && > + (pdev->vendor == PCI_VENDOR_ID_INTEL) && > + (((pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA) || > + ((pdev->class >> 8) == PCI_CLASS_DISPLAY_OTHER)) && > + (pci_dev_id(pdev) == PCI_DEVID(0, PCI_DEVFN(2, 0)))) { Sorry I wasn't available to reply on previous thread before v2 was posted, but given that we have vfio_pci_is_vga() we should use it rather than duplicate the contents. I think that suggests we should create a similar helper for display_other. Alternatively we should maybe consider if it's sufficient to use just the base class. The DEVID of course does not include the domain, which make it a rather suspect check already. What do the discrete cards report at 0xfc in config space? If it's zero or -1 or points to something that we can't memremap() or points to contents that doesn't include the opregion signature, then we'll already exit out of vfio_pci_igd_init(). Is there actually a case that we're actually configuring IGD specific regions for a discrete card? Thanks, Alex > ret = vfio_pci_igd_init(vdev); > if (ret && ret != -ENODEV) { > pci_warn(pdev, "Failed to setup Intel IGD regions\n");
On 1/4/25 01:44, Alex Williamson wrote: > On Tue, 31 Dec 2024 00:10:54 +0800 > Tomita Moeko <tomitamoeko@gmail.com> wrote: > >> igd device can either expose as a VGA controller or display controller >> depending on whether it is configured as the primary display device in >> BIOS. In both cases, the OpRegion may be present. Also checks if the >> device is at bdf 00:02.0 to avoid setting up igd-specific regions on >> Intel discrete GPUs. >> >> Signed-off-by: Tomita Moeko <tomitamoeko@gmail.com> >> --- >> Changelog: >> v2: >> Fix misuse of pci_get_domain_bus_and_slot(), now only compares bdf >> without touching device reference count. >> Link: https://lore.kernel.org/all/20241229155140.7434-1-tomitamoeko@gmail.com/ >> >> drivers/vfio/pci/vfio_pci.c | 8 +++++--- >> 1 file changed, 5 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c >> index e727941f589d..906a1db46d15 100644 >> --- a/drivers/vfio/pci/vfio_pci.c >> +++ b/drivers/vfio/pci/vfio_pci.c >> @@ -111,9 +111,11 @@ static int vfio_pci_open_device(struct vfio_device *core_vdev) >> if (ret) >> return ret; >> >> - if (vfio_pci_is_vga(pdev) && >> - pdev->vendor == PCI_VENDOR_ID_INTEL && >> - IS_ENABLED(CONFIG_VFIO_PCI_IGD)) { >> + if (IS_ENABLED(CONFIG_VFIO_PCI_IGD) && >> + (pdev->vendor == PCI_VENDOR_ID_INTEL) && >> + (((pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA) || >> + ((pdev->class >> 8) == PCI_CLASS_DISPLAY_OTHER)) && >> + (pci_dev_id(pdev) == PCI_DEVID(0, PCI_DEVFN(2, 0)))) { > > Sorry I wasn't available to reply on previous thread before v2 was > posted, but given that we have vfio_pci_is_vga() we should use it > rather than duplicate the contents. I think that suggests we should > create a similar helper for display_other. Alternatively we should > maybe consider if it's sufficient to use just the base class. I think using the base class is okay here. AFAIK intel doesn't has any devices reported as XGA or 3D controller. > The DEVID of course does not include the domain, which make it a rather > suspect check already. What do the discrete cards report at 0xfc in > config space? If it's zero or -1 or points to something that we can't > memremap() or points to contents that doesn't include the opregion > signature, then we'll already exit out of vfio_pci_igd_init(). Is > there actually a case that we're actually configuring IGD specific > regions for a discrete card? Thanks, > > Alex Checking (pci_domain_nr(pdev->bus) == 0) seems okay. I tried on a discrate Arc A770, there is 0 at 0xFC, so vfio_pci_igd_init() returns with -NODEV and the device is skipped. Shall I remove the BDF check? It seems to be unnecessary, my intention is to ensure it is really an igd since it can only be at 0000:00:02.0. >> ret = vfio_pci_igd_init(vdev); >> if (ret && ret != -ENODEV) { >> pci_warn(pdev, "Failed to setup Intel IGD regions\n"); >
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index e727941f589d..906a1db46d15 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -111,9 +111,11 @@ static int vfio_pci_open_device(struct vfio_device *core_vdev) if (ret) return ret; - if (vfio_pci_is_vga(pdev) && - pdev->vendor == PCI_VENDOR_ID_INTEL && - IS_ENABLED(CONFIG_VFIO_PCI_IGD)) { + if (IS_ENABLED(CONFIG_VFIO_PCI_IGD) && + (pdev->vendor == PCI_VENDOR_ID_INTEL) && + (((pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA) || + ((pdev->class >> 8) == PCI_CLASS_DISPLAY_OTHER)) && + (pci_dev_id(pdev) == PCI_DEVID(0, PCI_DEVFN(2, 0)))) { ret = vfio_pci_igd_init(vdev); if (ret && ret != -ENODEV) { pci_warn(pdev, "Failed to setup Intel IGD regions\n");
igd device can either expose as a VGA controller or display controller depending on whether it is configured as the primary display device in BIOS. In both cases, the OpRegion may be present. Also checks if the device is at bdf 00:02.0 to avoid setting up igd-specific regions on Intel discrete GPUs. Signed-off-by: Tomita Moeko <tomitamoeko@gmail.com> --- Changelog: v2: Fix misuse of pci_get_domain_bus_and_slot(), now only compares bdf without touching device reference count. Link: https://lore.kernel.org/all/20241229155140.7434-1-tomitamoeko@gmail.com/ drivers/vfio/pci/vfio_pci.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)