From: Chris Wilson <[email protected]> commit 8195400f7ea95399f721ad21f4d663a62c65036f upstream.
If i915.ko is being used as a passthrough device, it does not know if the host is using intel_iommu. Mixing the iommu and gfx causes a few issues (such as scanout overfetch) which we need to workaround inside the driver, so if we detect we are running under a hypervisor, also assume the device access is being virtualised. Reported-by: Stefan Fritsch <[email protected]> Suggested-by: Stefan Fritsch <[email protected]> Signed-off-by: Chris Wilson <[email protected]> Cc: Zhenyu Wang <[email protected]> Cc: Joonas Lahtinen <[email protected]> Cc: Stefan Fritsch <[email protected]> Cc: [email protected] Tested-by: Stefan Fritsch <[email protected]> Reviewed-by: Zhenyu Wang <[email protected]> Link: https://patchwork.freedesktop.org/patch/msgid/[email protected] (cherry picked from commit f566fdcd6cc49a9d5b5d782f56e3e7cb243f01b8) Signed-off-by: Rodrigo Vivi <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/gpu/drm/i915/i915_drv.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -33,6 +33,8 @@ #include <uapi/drm/i915_drm.h> #include <uapi/drm/drm_fourcc.h> +#include <asm/hypervisor.h> + #include <linux/io-mapping.h> #include <linux/i2c.h> #include <linux/i2c-algo-bit.h> @@ -1716,7 +1718,9 @@ static inline bool intel_vtd_active(void if (intel_iommu_gfx_mapped) return true; #endif - return false; + + /* Running as a guest, we assume the host is enforcing VT'd */ + return !hypervisor_is_type(X86_HYPER_NATIVE); } static inline bool intel_scanout_needs_vtd_wa(struct drm_i915_private *dev_priv)
