drm/i915/gvt: Disable access to stolen memory as a guest

BugLink: http://bugs.launchpad.net/bugs/1673118
commit ddd09373628adcbdc3f7b9098d22328834f8d772 upstream.

Explicitly disable stolen memory when running as a guest in a virtual
machine, since the memory is not mediated between clients and reserved
entirely for the host. The actual size should be reported as zero, but
like every other quirk we want to tell the user what is happening.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99028
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>
Link: http://patchwork.freedesktop.org/patch/msgid/20161109103905.17860-1-chris@chris-wilson.co.uk
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
(cherry picked from commit 04a68a35ce6d7b54749989f943993020f48fed62)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index abc78bbfc1dcd0fbc6373222c3801929d1dfd2d4..7325230fff028c73007a9510cf62e78637b64230 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -414,6 +414,11 @@ int i915_gem_init_stolen(struct drm_i915_private *dev_priv)
 
        mutex_init(&dev_priv->mm.stolen_lock);
 
+       if (intel_vgpu_active(dev_priv)) {
+               DRM_INFO("iGVT-g active, disabling use of stolen memory\n");
+               return 0;
+       }
+
 #ifdef CONFIG_INTEL_IOMMU
        if (intel_iommu_gfx_mapped && INTEL_GEN(dev_priv) < 8) {
                DRM_INFO("DMAR active, disabling use of stolen memory\n");