motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-07 01:33:56 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

vfio/igd: Restrict legacy mode to Gen6-9 devices

Browse source 
Intel only provides legacy VBIOS for IGD up to Gen9, and there is no
CSM support on later devices. Additionally, Seabios can only handle
32-bit BDSM register used until Gen9. Since legacy mode requires VGA
capability, restrict it to Gen6 through Gen9 devices.

Link: https://lore.kernel.org/qemu-devel/20250325172239.27926-1-tomitamoeko@gmail.com/T/
Signed-off-by: Tomita Moeko <tomitamoeko@gmail.com>
Reviewed-by: Corvin Köhne <c.koehne@beckhoff.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20250505170305.23622-2-tomitamoeko@gmail.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
This commit is contained in:
Tomita Moeko 2025-05-06 01:02:57 +08:00 • committed by Cédric Le Goater
parent 07f86929e5
commit dd69d84604
2 changed files with 6 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

1
docs/igd-assign.txt
View file

@ -47,6 +47,7 @@ Intel document [1] shows how to dump VBIOS to file. For UEFI Option ROM, see
QEMU also provides a "Legacy" mode that implicitly enables full functionality QEMU also provides a "Legacy" mode that implicitly enables full functionality
on IGD, it is automatically enabled when on IGD, it is automatically enabled when
* IGD generation is 6 to 9 (Sandy Bridge to Comet Lake)
* Machine type is i440fx * Machine type is i440fx
* IGD is assigned to guest BDF 00:02.0 * IGD is assigned to guest BDF 00:02.0
* ROM BAR or romfile is present * ROM BAR or romfile is present

6
hw/vfio/igd.c
View file

@ -517,11 +517,13 @@ static bool vfio_pci_igd_config_quirk(VFIOPCIDevice *vdev, Error **errp)
/* /*
* For backward compatibility, enable legacy mode when * For backward compatibility, enable legacy mode when
* - Device geneation is 6 to 9 (including both)
* - Machine type is i440fx (pc_piix) * - Machine type is i440fx (pc_piix)
* - IGD device is at guest BDF 00:02.0 * - IGD device is at guest BDF 00:02.0
* - Not manually disabled by x-igd-legacy-mode=off * - Not manually disabled by x-igd-legacy-mode=off
*/ */
if ((vdev->igd_legacy_mode != ON_OFF_AUTO_OFF) && if ((vdev->igd_legacy_mode != ON_OFF_AUTO_OFF) &&
(gen >= 6 && gen <= 9) &&
!strcmp(MACHINE_GET_CLASS(qdev_get_machine())->family, "pc_piix") && !strcmp(MACHINE_GET_CLASS(qdev_get_machine())->family, "pc_piix") &&
(&vdev->pdev == pci_find_device(pci_device_root_bus(&vdev->pdev), (&vdev->pdev == pci_find_device(pci_device_root_bus(&vdev->pdev),
0, PCI_DEVFN(0x2, 0)))) { 0, PCI_DEVFN(0x2, 0)))) {
@ -566,7 +568,9 @@ static bool vfio_pci_igd_config_quirk(VFIOPCIDevice *vdev, Error **errp)
vdev->features |= VFIO_FEATURE_ENABLE_IGD_LPC; vdev->features |= VFIO_FEATURE_ENABLE_IGD_LPC;
} else if (vdev->igd_legacy_mode == ON_OFF_AUTO_ON) { } else if (vdev->igd_legacy_mode == ON_OFF_AUTO_ON) {
error_setg(&err, error_setg(&err,
"Machine is not i440fx or assigned BDF is not 00:02.0"); "Machine is not i440fx, assigned BDF is not 00:02.0, "
"or device %04x (gen %d) doesn't support legacy mode",
vdev->device_id, gen);
goto error; goto error;
} }