[PATCH] drm/i915/gvt: Fix GFX_MODE handling

[Colin Xu]

Enter failsafe if vgpu tries to change GFX_MODE controlled by host.

Signed-off-by: Colin Xu<colin.xu at intel.com>
---
  drivers/gpu/drm/i915/gvt/handlers.c | 14 ++++++++++++++
  1 file changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/i915/gvt/handlers.c b/drivers/gpu/drm/i915/gvt/handlers.c
index b4fc7f95cbe1..edb1416585f5 100644
--- a/drivers/gpu/drm/i915/gvt/handlers.c
+++ b/drivers/gpu/drm/i915/gvt/handlers.c
@@ -1692,8 +1692,22 @@ static int ring_mode_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
  	bool enable_execlist;
  	int ret;
  
+	(*(u32 *)p_data) &= ~_MASKED_BIT_ENABLE(1);
+	if (IS_COFFEELAKE(vgpu->gvt->dev_priv))
+		(*(u32 *)p_data) &= ~_MASKED_BIT_ENABLE(2);
  	write_vreg(vgpu, offset, p_data, bytes);
  
+	if (data & _MASKED_BIT_ENABLE(1)) {
+		enter_failsafe_mode(vgpu, GVT_FAILSAFE_UNSUPPORTED_GUEST);
+		return 0;
+	}
+
+	if (IS_COFFEELAKE(vgpu->gvt->dev_priv) &&
+	    data & _MASKED_BIT_ENABLE(2)) {
+		enter_failsafe_mode(vgpu, GVT_FAILSAFE_UNSUPPORTED_GUEST);
+		return 0;
+	}
+
  	/* when PPGTT mode enabled, we will check if guest has called
  	 * pvinfo, if not, we will treat this guest as non-gvtg-aware
  	 * guest, and stop emulating its cfg space, mmio, gtt, etc.

-- 
2.21.0