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authorChris Wilson <chris@chris-wilson.co.uk>2020-10-19 11:15:23 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-11-05 11:07:01 +0100
commit1e066477433b1a6451abda0307c13a06a23cdaa2 (patch)
treeac6578076f3a6ffcf44efc85fa7b7b5f266f5fde
parent72b3bcab2003ddf755f275fa2cfbc3de479d3db3 (diff)
downloadlinux-stable-rc-1e066477433b1a6451abda0307c13a06a23cdaa2.tar.gz
drm/i915: Force VT'd workarounds when running as a guest OS
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 <sf@sfritsch.de> Suggested-by: Stefan Fritsch <sf@sfritsch.de> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Zhenyu Wang <zhenyuw@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Stefan Fritsch <sf@sfritsch.de> Cc: stable@vger.kernel.org Tested-by: Stefan Fritsch <sf@sfritsch.de> Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20201019101523.4145-1-chris@chris-wilson.co.uk (cherry picked from commit f566fdcd6cc49a9d5b5d782f56e3e7cb243f01b8) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/gpu/drm/i915/i915_drv.h6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index a5fb7404b29ea..816781f209d66 100644
--- 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>
@@ -3141,7 +3143,9 @@ 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)