[Intel-gfx] [PATCH] drm/i915/gtt: Revert "Disable read-only support under GVT"

[hang.yuan at linux.intel.com]

From: Hang Yuan <hang.yuan at linux.intel.com>

This reverts commit c9e666880de5a1fed04dc412b046916d542b72dd.

Checked GVT codes that guest PPGTT PTE flag bits are propagated
to shadow PTE. Read/write bit is not changed. Further tested by
i915 self-test case "igt_ctx_readonly". No error or GPU hang was
detected. So enable read-only support under GVT.

Signed-off-by: Hang Yuan <hang.yuan at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_gem_gtt.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 19b2d99..bdf9f9f 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -1602,12 +1602,8 @@ static struct i915_hw_ppgtt *gen8_ppgtt_create(struct drm_i915_private *i915)
 		1ULL << 48 :
 		1ULL << 32;
 
-	/*
-	 * From bdw, there is support for read-only pages in the PPGTT.
-	 *
-	 * XXX GVT is not honouring the lack of RW in the PTE bits.
-	 */
-	ppgtt->vm.has_read_only = !intel_vgpu_active(i915);
+	/* From bdw, there is support for read-only pages in the PPGTT. */
+	ppgtt->vm.has_read_only = true;
 
 	i915_address_space_init(&ppgtt->vm, i915);
 
-- 
2.7.4