ASLS register represents the base address of OpRegion, and it is programmed with HPA. In IGD passthrough scenario, it needs to be reprogrammed with GPA by guest firmware. To prevent guest accessing wrong memory range, ASLS should always be emulated and cleared.
In GVT-g scenario, emulating ASLS is unnecessary as access is handled by kvmgt backend [1]. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpu/drm/i915/gvt/cfg_space.c?h=v6.14#n295 Signed-off-by: Tomita Moeko <tomitamo...@gmail.com> --- hw/vfio/igd.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/hw/vfio/igd.c b/hw/vfio/igd.c index e06484c911..b1fce76f72 100644 --- a/hw/vfio/igd.c +++ b/hw/vfio/igd.c @@ -182,10 +182,6 @@ static bool vfio_pci_igd_opregion_init(VFIOPCIDevice *vdev, trace_vfio_pci_igd_opregion_enabled(vdev->vbasedev.name); - pci_set_long(vdev->pdev.config + IGD_ASLS, 0); - pci_set_long(vdev->pdev.wmask + IGD_ASLS, ~0); - pci_set_long(vdev->emulated_config_bits + IGD_ASLS, ~0); - return true; } @@ -584,7 +580,15 @@ static bool vfio_pci_igd_config_quirk(VFIOPCIDevice *vdev, Error **errp) if ((vdev->features & VFIO_FEATURE_ENABLE_IGD_LPC) && !vfio_pci_igd_setup_lpc_bridge(vdev, errp)) { goto error; - } + } + + /* + * ASLS (OpRegion address) is read-only, emulated + * It contains HPA, guest firmware need to reprogram it with GPA. + */ + pci_set_long(vdev->pdev.config + IGD_ASLS, 0); + pci_set_long(vdev->pdev.wmask + IGD_ASLS, ~0); + pci_set_long(vdev->emulated_config_bits + IGD_ASLS, ~0); /* * Allow user to override dsm size using x-igd-gms option, in multiples of -- 2.47.2
