drm/i915/gvt: set shadow entry to scratch page while p2m failed

Sometimes guest driver will only update partial of the GGTT entry then
access it. In this situation a failure will happen while translating
the gpa to hpa.
Now in this situation we let the corresponding shadow entry pointing
to a scratch page.

Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Xiaoguang Chen <xiaoguang.chen@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
This commit is contained in:
Xiaoguang Chen 2017-03-21 10:54:21 +08:00 committed by Zhenyu Wang
parent 14f5ba26aa
commit 359b693100

View File

@ -1837,11 +1837,15 @@ static int emulate_gtt_mmio_write(struct intel_vgpu *vgpu, unsigned int off,
ret = gtt_entry_p2m(vgpu, &e, &m);
if (ret) {
gvt_vgpu_err("fail to translate guest gtt entry\n");
return ret;
/* guest driver may read/write the entry when partial
* update the entry in this situation p2m will fail
* settting the shadow entry to point to a scratch page
*/
ops->set_pfn(&m, gvt->gtt.scratch_ggtt_mfn);
}
} else {
m = e;
m.val64 = 0;
ops->set_pfn(&m, gvt->gtt.scratch_ggtt_mfn);
}
ggtt_set_shadow_entry(ggtt_mm, &m, g_gtt_index);