Add VIRTGPU_PARAM_HOST_SHM_PAGE_SIZE as a param that can be read with
VIRTGPU_GETPARAM by userspace applications running in the guest to
obtain the host's page size and find out the right alignment to be used
in shared memory allocations.
Signed-off-by: Sergio Lopez <slp@xxxxxxxxxx>
---
drivers/gpu/drm/virtio/virtgpu_ioctl.c | 5 +++++
include/uapi/drm/virtgpu_drm.h | 1 +
2 files changed, 6 insertions(+)
diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index c33c057365f85a2ace536f91655c903036827312..4b49635b4fe1d4256f219823341cef8e5fa8f029 100644
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -117,6 +117,11 @@ static int virtio_gpu_getparam_ioctl(struct drm_device *dev, void *data,
case VIRTGPU_PARAM_EXPLICIT_DEBUG_NAME:
value = vgdev->has_context_init ? 1 : 0;
break;
+ case VIRTGPU_PARAM_HOST_SHM_PAGE_SIZE:
+ if (!vgdev->has_host_visible)
+ return -EINVAL;
+ value = vgdev->host_visible_region.page_size;
+ break;
default:
return -EINVAL;
}
diff --git a/include/uapi/drm/virtgpu_drm.h b/include/uapi/drm/virtgpu_drm.h
index c2ce71987e9bb816d13a300679336cb756f1cbcf..72db6b3339e0dcaf550acbf5ac4381a6e5c2216d 100644
--- a/include/uapi/drm/virtgpu_drm.h
+++ b/include/uapi/drm/virtgpu_drm.h
@@ -98,6 +98,7 @@ struct drm_virtgpu_execbuffer {
#define VIRTGPU_PARAM_CONTEXT_INIT 6 /* DRM_VIRTGPU_CONTEXT_INIT */
#define VIRTGPU_PARAM_SUPPORTED_CAPSET_IDs 7 /* Bitmask of supported capability set ids */
#define VIRTGPU_PARAM_EXPLICIT_DEBUG_NAME 8 /* Ability to set debug name from userspace */
+#define VIRTGPU_PARAM_HOST_SHM_PAGE_SIZE 9 /* Host SHM page size, with format PAGE_SIZE >> 12 */
struct drm_virtgpu_getparam {
__u64 param;
--
2.48.1
