drm/vmwgfx: Implement virtual crc generation

crc checksums are used to validate the output. Normally they're part
of the actual display hardware but on virtual stack there's nothing
to automatically generate them.

Implement crc generation for the vmwgfx stack. This works only on
screen targets, where it's possibly to easily make sure that the
guest side contents of the surface matches the host sides output.

Just like the vblank support, crc generation can only be enabled via:
guestinfo.vmwgfx.vkms_enable = "TRUE"
option in the vmx file.

Makes IGT's kms_pipe_crc_basic pass and allows a huge number of other
IGT tests which require CRC generation of the output to actually run
on vmwgfx. Makes it possible to actually validate a lof of the kms and
drm functionality with vmwgfx.

Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>
Acked-by: Martin Krastev <martin.krastev@broadcom.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240412025511.78553-3-zack.rusin@broadcom.com

1 files changed, 20 insertions, 12 deletions

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
index ca300c7427d2..848dba09981b 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
@@ -1064,6 +1064,22 @@ void vmw_resource_dirty_update(struct vmw_resource *res, pgoff_t start,
 					   end << PAGE_SHIFT);
 }
 
+int vmw_resource_clean(struct vmw_resource *res)
+{
+	int ret = 0;
+
+	if (res->res_dirty) {
+		if (!res->func->clean)
+			return -EINVAL;
+
+		ret = res->func->clean(res);
+		if (ret)
+			return ret;
+		res->res_dirty = false;
+	}
+	return ret;
+}
+
 /**
  * vmw_resources_clean - Clean resources intersecting a mob range
  * @vbo: The mob buffer object
@@ -1080,6 +1096,7 @@ int vmw_resources_clean(struct vmw_bo *vbo, pgoff_t start,
 	unsigned long res_start = start << PAGE_SHIFT;
 	unsigned long res_end = end << PAGE_SHIFT;
 	unsigned long last_cleaned = 0;
+	int ret;
 
 	/*
 	 * Find the resource with lowest backup_offset that intersects the
@@ -1106,18 +1123,9 @@ int vmw_resources_clean(struct vmw_bo *vbo, pgoff_t start,
 	 * intersecting the range.
 	 */
 	while (found) {
-		if (found->res_dirty) {
-			int ret;
-
-			if (!found->func->clean)
-				return -EINVAL;
-
-			ret = found->func->clean(found);
-			if (ret)
-				return ret;
-
-			found->res_dirty = false;
-		}
+		ret = vmw_resource_clean(found);
+		if (ret)
+			return ret;
 		last_cleaned = found->guest_memory_offset + found->guest_memory_size;
 		cur = rb_next(&found->mob_node);
 		if (!cur)