drm/i915: fix TLB invalidation for Gen12 video and compute engines

Origin: https://git.kernel.org/linus/04aa64375f48a5d430b5550d9271f8428883e550
Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2022-4139

In case of Gen12 video and compute engines, TLB_INV registers are masked -
to modify one bit, corresponding bit in upper half of the register must
be enabled, otherwise nothing happens.

CVE: CVE-2022-4139
Suggested-by: Chris Wilson <chris.p.wilson@intel.com>
Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Fixes: 7938d61591d3 ("drm/i915: Flush TLBs before releasing backing store")
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Gbp-Pq: Topic bugfix/x86
Gbp-Pq: Name drm-i915-fix-TLB-invalidation-for-Gen12-video-and-co.patch

diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
index f435e06125aab0b99d79a842b857c6cffdfab068..f158f6a08e75719e415f98420ea14ab50d3c39bc 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_gt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt.c
@@ -961,6 +961,11 @@ static void mmio_invalidate_full(struct intel_gt *gt)
                if (!i915_mmio_reg_offset(rb.reg))
                        continue;
 
+               if (GRAPHICS_VER(i915) == 12 && (engine->class == VIDEO_DECODE_CLASS ||
+                   engine->class == VIDEO_ENHANCEMENT_CLASS ||
+                   engine->class == COMPUTE_CLASS))
+                       rb.bit = _MASKED_BIT_ENABLE(rb.bit);
+
                intel_uncore_write_fw(uncore, rb.reg, rb.bit);
                awake |= engine->mask;
        }