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authorChris Wilson <chris@chris-wilson.co.uk>2020-10-19 11:15:23 +0100
committerRodrigo Vivi <rodrigo.vivi@intel.com>2020-10-21 08:32:30 -0400
commit8195400f7ea95399f721ad21f4d663a62c65036f (patch)
tree8620d1616fb07e2da14fc1f9ba27b9decc735e71 /drivers
parent3da3c5c1c9825c24168f27b021339e90af37e969 (diff)
drm/i915: Force VT'd workarounds when running as a guest OS
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>
Diffstat (limited to 'drivers')
-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 eef9a821c49c..8426d5974669 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>
@@ -1760,7 +1762,9 @@ 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)