Thanks for the comments, Ill make a new patch with a `vfio_is_display`
function`,
should I still change all uses of the `vfio_is_vga` function to use that one
even if the other quirks aren't needed in that configuration?
ma 19.5.2025 klo 20.28 Tomita Moeko (tomitamo...@gmail.com) kirjoitti:
> On 5/20/25 01:15, Alex Williamson wrote:
> > [Please Cc maintainers - added here]
> >
> > On Mon, 19 May 2025 18:08:39 +0300
> > Qwinci <qwinci...@gmail.com> wrote:
> >
> >> Change the IGD detection logic to also accept gpus with
> >> PCI_CLASS_DISPLAY_OTHER class which is used if the igpu is not
> >> set as the primary boot gpu.
> >>
> >> Signed-off-by: Qwinci <qwinci...@gmail.com>
> >> ---
> >> hw/vfio/igd.c | 16 +++++++++++++---
> >> 1 file changed, 13 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/hw/vfio/igd.c b/hw/vfio/igd.c
> >> index e7952d15a0..1ddfcc2c17 100644
> >> --- a/hw/vfio/igd.c
> >> +++ b/hw/vfio/igd.c
> >> @@ -454,6 +454,16 @@ static bool vfio_pci_igd_override_gms(int gen,
> uint32_t gms, uint32_t *gmch)
> >> #define IGD_GGC_MMIO_OFFSET 0x108040
> >> #define IGD_BDSM_MMIO_OFFSET 0x1080C0
> >>
> >> +static bool is_igd(VFIOPCIDevice *vdev) {
> >> + if (vfio_is_vga(vdev)) {
> >> + return true;
> >> + }
> >> +
> >> + PCIDevice *pdev = &vdev->pdev;
> >> + uint16_t class = pci_get_word(pdev->config + PCI_CLASS_DEVICE);
> >> + return class == PCI_CLASS_DISPLAY_OTHER;
> >> +}
> >
> > But the function isn't detecting IGD, it's detecting VGA or DISPLAY
> > class devices. So it's misnamed and we might want a new
> > vfio_is_display() and if necessary a wrapper for both that tests
> > vfio_is_vga_or_display(), or maybe a vfio_is_base_display() if we want
> > to test only the base class.
>
> +1, matching the base class is enough here I think.
>
> > More importantly maybe, sure there might be IGD as non-primary
> > configurations, but are the quirks still relevant to those devices?
> > Which ones? Thanks,
> >
> > Alex
>
> Actually this is what I've worked on for a while. Only the OpRegion
> quirk is needed in this configuration, Windows driver requires it.
> Additionally, legacy mode should be disabled when IGD is non-primary as
> VGA ranges are not routed to IGD.
>
> It also requires a more recent version kernel (6.15+) [1] for OpRegion
> support on IGD as non-primary graphics.
>
> [1]
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=41112160ca87d6b5280813ef61f1c35bb9ee2f82
>
> Thanks,
> Moeko
>
> >> void vfio_probe_igd_bar0_quirk(VFIOPCIDevice *vdev, int nr)
> >> {
> >> VFIOQuirk *ggc_quirk, *bdsm_quirk;
> >> @@ -461,7 +471,7 @@ void vfio_probe_igd_bar0_quirk(VFIOPCIDevice *vdev,
> int nr)
> >> int gen;
> >>
> >> if (!vfio_pci_is(vdev, PCI_VENDOR_ID_INTEL, PCI_ANY_ID) ||
> >> - !vfio_is_vga(vdev) || nr != 0) {
> >> + !is_igd(vdev) || nr != 0) {
> >> return;
> >> }
> >>
> >> @@ -519,7 +529,7 @@ static bool vfio_pci_igd_config_quirk(VFIOPCIDevice
> *vdev, Error **errp)
> >> Error *err = NULL;
> >>
> >> if (!vfio_pci_is(vdev, PCI_VENDOR_ID_INTEL, PCI_ANY_ID) ||
> >> - !vfio_is_vga(vdev)) {
> >> + !is_igd(vdev)) {
> >> return true;
> >> }
> >>
> >> @@ -685,7 +695,7 @@ static bool
> vfio_pci_kvmgt_config_quirk(VFIOPCIDevice *vdev, Error **errp)
> >> int gen;
> >>
> >> if (!vfio_pci_is(vdev, PCI_VENDOR_ID_INTEL, PCI_ANY_ID) ||
> >> - !vfio_is_vga(vdev)) {
> >> + !is_igd(vdev)) {
> >> return true;
> >> }
> >>
> >
>
