Add a userptr address field so userspace can request a blob backed by an existing process mapping. A non-zero userptr selects that path; probe VIRTGPU_PARAM_USERPTR before using the field.
GPU-readonly backing is requested with the virtio CREATE_BLOB wire flag VIRTIO_GPU_BLOB_FLAG_USE_READONLY (also VIRTGPU_BLOB_FLAG_USE_READONLY). The device MUST NOT write such a resource. The guest pins without FOLL_WRITE only when the device advertised VIRTIO_GPU_F_BLOB_READONLY (VIRTGPU_PARAM_BLOB_READONLY). Signed-off-by: Honglei Huang <[email protected]> --- include/uapi/drm/virtgpu_drm.h | 13 +++++++++++++ include/uapi/linux/virtio_gpu.h | 6 ++++++ 2 files changed, 19 insertions(+) diff --git a/include/uapi/drm/virtgpu_drm.h b/include/uapi/drm/virtgpu_drm.h index 95587e12ae..80f73b3276 100644 --- a/include/uapi/drm/virtgpu_drm.h +++ b/include/uapi/drm/virtgpu_drm.h @@ -99,6 +99,8 @@ struct drm_virtgpu_execbuffer { #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_BLOB_ALIGNMENT 9 /* Device alignment requirements for blobs */ +#define VIRTGPU_PARAM_USERPTR 10 /* CREATE_BLOB userptr field is supported */ +#define VIRTGPU_PARAM_BLOB_READONLY 11 /* VIRTGPU_BLOB_FLAG_USE_READONLY is honored */ struct drm_virtgpu_getparam { __u64 param; @@ -186,6 +188,10 @@ struct drm_virtgpu_resource_create_blob { #define VIRTGPU_BLOB_FLAG_USE_MAPPABLE 0x0001 #define VIRTGPU_BLOB_FLAG_USE_SHAREABLE 0x0002 #define VIRTGPU_BLOB_FLAG_USE_CROSS_DEVICE 0x0004 +/* Wire flag: device MUST NOT write. Guest pins without FOLL_WRITE. + * Rejected unless VIRTGPU_PARAM_BLOB_READONLY is 1. + */ +#define VIRTGPU_BLOB_FLAG_USE_READONLY 0x0008 /* zero is invalid blob_mem */ __u32 blob_mem; __u32 blob_flags; @@ -205,6 +211,13 @@ struct drm_virtgpu_resource_create_blob { #define DRM_VIRTGPU_BLOB_FLAG_HINT_DEFER_MAPPING 0x0001 __u32 blob_hints; __u32 pad2; + + /* + * Guest VA to pin as blob backing. Non-zero selects the userptr + * path and is valid only with VIRTGPU_BLOB_MEM_GUEST. Must be 0 + * otherwise. Probe VIRTGPU_PARAM_USERPTR before using this field. + */ + __u64 userptr; }; #define VIRTGPU_CONTEXT_PARAM_CAPSET_ID 0x0001 diff --git a/include/uapi/linux/virtio_gpu.h b/include/uapi/linux/virtio_gpu.h index 3d4dfadc9d..33f5332e59 100644 --- a/include/uapi/linux/virtio_gpu.h +++ b/include/uapi/linux/virtio_gpu.h @@ -72,6 +72,10 @@ * must be aligned to that value. */ #define VIRTIO_GPU_F_BLOB_ALIGNMENT 5 +/* + * VIRTIO_GPU_BLOB_FLAG_USE_READONLY + */ +#define VIRTIO_GPU_F_BLOB_READONLY 6 enum virtio_gpu_ctrl_type { VIRTIO_GPU_UNDEFINED = 0, @@ -415,6 +419,8 @@ struct virtio_gpu_resource_create_blob { #define VIRTIO_GPU_BLOB_FLAG_USE_MAPPABLE 0x0001 #define VIRTIO_GPU_BLOB_FLAG_USE_SHAREABLE 0x0002 #define VIRTIO_GPU_BLOB_FLAG_USE_CROSS_DEVICE 0x0004 +/* Device MUST NOT write. Driver may pin read-only guest pages. */ +#define VIRTIO_GPU_BLOB_FLAG_USE_READONLY 0x0008 /* zero is invalid blob mem */ __le32 blob_mem; __le32 blob_flags; -- 2.34.1
