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 causing 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 --- drivers/gpu/drm/i915/i915_drv.h | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 1a5729932c81..02a3dac412d8 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> @@ -1760,6 +1762,13 @@ static inline bool intel_vtd_active(void) if (intel_iommu_gfx_mapped) return true; #endif + +#ifdef CONFIG_HYPERVISOR_GUEST + /* Running as a guest, we assume the host is enforcing VT'd */ + if (x86_hyper_type != X86_HYPER_NATIVE) + return true; +#endif + return false; }
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 causing 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 --- drivers/gpu/drm/i915/i915_drv.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 1a5729932c81..bcd8650603d8 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)
Works for me and makes the fault messages disappear. Thanks.
Tested-by: Stefan Fritsch sf@sfritsch.de
On Mon, 19 Oct 2020, Chris Wilson wrote:
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 causing 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
drivers/gpu/drm/i915/i915_drv.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 1a5729932c81..bcd8650603d8 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)
Quoting Stefan Fritsch (2020-10-19 14:08:17)
Works for me and makes the fault messages disappear. Thanks.
Tested-by: Stefan Fritsch sf@sfritsch.de
Thanks for the report and testing. In hindsight, this should have been obvious.
Pushed, -Chris
On 2020.10.19 11:15:23 +0100, Chris Wilson wrote:
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 causing 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
drivers/gpu/drm/i915/i915_drv.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 1a5729932c81..bcd8650603d8 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) --
Reviewed-by: Zhenyu Wang zhenyuw@linux.intel.com
linux-stable-mirror@lists.linaro.org
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Chris Wilson -
Stefan Fritsch -
Zhenyu Wang