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;
>> }
>>
>
