drm/i915/gvt: Handle special sequence on PDE IPS bit

If the guest update the 64K gtt entry before changing IPS bit of PDE, we
need to re-shadow the whole page table. Because we have ignored all
updates to unused entries.

Signed-off-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
index 5a66d0f..b40c615 100644 (file)
--- a/drivers/gpu/drm/i915/gvt/gtt.c
+++ b/drivers/gpu/drm/i915/gvt/gtt.c
@@ -1045,14 +1045,24 @@ static struct intel_vgpu_ppgtt_spt *ppgtt_populate_spt_by_guest_entry(
 
        GEM_BUG_ON(!gtt_type_is_pt(get_next_pt_type(we->type)));
 
+       if (we->type == GTT_TYPE_PPGTT_PDE_ENTRY)
+               ips = vgpu_ips_enabled(vgpu) && ops->test_ips(we);
+
        spt = intel_vgpu_find_spt_by_gfn(vgpu, ops->get_pfn(we));
-       if (spt)
+       if (spt) {
                ppgtt_get_spt(spt);
-       else {
-               int type = get_next_pt_type(we->type);
 
-               if (we->type == GTT_TYPE_PPGTT_PDE_ENTRY)
-                       ips = vgpu_ips_enabled(vgpu) && ops->test_ips(we);
+               if (ips != spt->guest_page.pde_ips) {
+                       spt->guest_page.pde_ips = ips;
+
+                       gvt_dbg_mm("reshadow PDE since ips changed\n");
+                       clear_page(spt->shadow_page.vaddr);
+                       ret = ppgtt_populate_spt(spt);
+                       if (ret)
+                               goto fail;
+               }
+       } else {
+               int type = get_next_pt_type(we->type);
 
                spt = ppgtt_alloc_spt_gfn(vgpu, type, ops->get_pfn(we), ips);
                if (IS_ERR(spt)) {