drm/i915/gvt: save RING_HEAD into vreg when vgpu switched out
Save RING_HEAD into vgpu reg when vgpu switched out and report
it's value back to guest.
v6: addressed comment for ring head wrap count support. (Zhenyu)
v5: ring head wrap count support.
v4: updated HEAD/TAIL with guest value, not host value. (Yan Zhao)
v3: save RING HEAD/TAIL vgpu reg in save_ring_hw_state. (Zhenyu Wang)
v2: save RING_TAIL as well during vgpu mmio switch to meet ring_is_idle
condition. (Fred Gao)
v1: based on input from Weinan. (Weinan Li)
[zhenyuw: Include this fix for possible future guest kernel that
would utilize RING_HEAD for hangcheck.]
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Xiaolin Zhang <xiaolin.zhang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
diff --git a/drivers/gpu/drm/i915/gvt/reg.h b/drivers/gpu/drm/i915/gvt/reg.h
index 33aaa14..5b66e14 100644
--- a/drivers/gpu/drm/i915/gvt/reg.h
+++ b/drivers/gpu/drm/i915/gvt/reg.h
@@ -102,6 +102,8 @@
#define FORCEWAKE_ACK_MEDIA_GEN9_REG 0x0D88
#define FORCEWAKE_ACK_HSW_REG 0x130044
+#define RB_HEAD_WRAP_CNT_MAX ((1 << 11) - 1)
+#define RB_HEAD_WRAP_CNT_OFF 21
#define RB_HEAD_OFF_MASK ((1U << 21) - (1U << 2))
#define RB_TAIL_OFF_MASK ((1U << 21) - (1U << 3))
#define RB_TAIL_SIZE_MASK ((1U << 21) - (1U << 12))