Merge tag 'gvt-fixes-2021-07-15' of https://github.com/intel/gvt-linux into drm-intel-fixes

gvt-fixes-2021-07-15

- Fix shadow ppgtt invalidation with proper D3 state tracking (Colin)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
From: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210715022237.GX12150@zhen-hp.sh.intel.com

drivers/gpu/drm/i915/gvt/handlers.c

@@ -1977,6 +1977,21 @@ static int elsp_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
 	if (drm_WARN_ON(&i915->drm, !engine))
 		return -EINVAL;
 
+	/*
+	 * Due to d3_entered is used to indicate skipping PPGTT invalidation on
+	 * vGPU reset, it's set on D0->D3 on PCI config write, and cleared after
+	 * vGPU reset if in resuming.
+	 * In S0ix exit, the device power state also transite from D3 to D0 as
+	 * S3 resume, but no vGPU reset (triggered by QEMU devic model). After
+	 * S0ix exit, all engines continue to work. However the d3_entered
+	 * remains set which will break next vGPU reset logic (miss the expected
+	 * PPGTT invalidation).
+	 * Engines can only work in D0. Thus the 1st elsp write gives GVT a
+	 * chance to clear d3_entered.
+	 */
+	if (vgpu->d3_entered)
+		vgpu->d3_entered = false;
+
 	execlist = &vgpu->submission.execlist[engine->id];
 
 	execlist->elsp_dwords.data[3 - execlist->elsp_dwords.index] = data;