virgl: rework blob support

Replace virgl_context::get_blob_pipe by virgl_context::get_blob,
which supports fd-based blobs.  There is also optional
virgl_context::get_blob_done to give the context a chance to
associate a resource with a blob.

Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>

src/virgl_context.h

@@ -29,10 +29,22 @@
 #include <stddef.h>
 #include <stdint.h>
 
-struct virgl_resource;
+#include "virgl_resource.h"
+
 struct vrend_transfer_info;
 struct pipe_resource;
 
+struct virgl_context_blob {
+   /* valid fd or pipe resource */
+   enum virgl_resource_fd_type type;
+   union {
+      int fd;
+      struct pipe_resource *pipe_resource;
+   } u;
+
+   void *renderer_data;
+};
+
 /**
  * Base class for renderer contexts.  For example, vrend_decode_ctx is a
  * subclass of virgl_context.
@@ -52,12 +64,26 @@ struct virgl_context {
                       const struct vrend_transfer_info *info,
                       int transfer_mode);
 
+   /* These are used to create a virgl_resource from a context object.
+    *
+    * get_blob returns a virgl_context_blob from which a virgl_resource can be
+    * created.  get_blob_done is optional and allows the context to associate
+    * the newly created resource with the context object.
+    *
+    * Note that get_blob is a one-time thing.  The context object might be
+    * destroyed or reject subsequent get_blob calls.
+    */
+   int (*get_blob)(struct virgl_context *ctx,
+                   uint64_t blob_id,
+                   uint32_t blob_flags,
+                   struct virgl_context_blob *blob);
+   void (*get_blob_done)(struct virgl_context *ctx,
+                         uint32_t res_id,
+                         struct virgl_context_blob *blob);
+
    int (*submit_cmd)(struct virgl_context *ctx,
                      const void *buffer,
                      size_t size);
-
-   struct pipe_resource *(*get_blob_pipe)(struct virgl_context *ctx,
-                                          uint64_t blob_id);
 };
 
 struct virgl_context_foreach_args {

src/virglrenderer.c

@@ -647,7 +647,7 @@ int virgl_renderer_execute(void *execute_args, uint32_t execute_size)
 int virgl_renderer_resource_create_blob(const struct virgl_renderer_resource_create_blob_args *args)
 {
    struct virgl_context *ctx;
-   struct pipe_resource *pipe_res;
+   struct virgl_context_blob blob;
    bool has_host_storage;
    bool has_guest_storage;
    int ret;
@@ -694,18 +694,33 @@ int virgl_renderer_resource_create_blob(const struct virgl_renderer_resource_cre
    if (!ctx)
       return -EINVAL;
 
-   pipe_res = ctx->get_blob_pipe(ctx, args->blob_id);
-   if (!pipe_res)
-      return -EINVAL;
+   ret = ctx->get_blob(ctx, args->blob_id, args->blob_flags, &blob);
+   if (ret)
+      return ret;
 
+   if (blob.type != VIRGL_RESOURCE_FD_INVALID) {
+      ret = virgl_resource_create_from_fd(args->res_handle,
+                                          blob.type,
+                                          blob.u.fd,
+                                          args->iovecs,
+                                          args->num_iovs);
+      if (ret) {
+         close(blob.u.fd);
+         return ret;
+      }
+   } else {
       ret = virgl_resource_create_from_pipe(args->res_handle,
-                                         pipe_res,
+                                            blob.u.pipe_resource,
                                             args->iovecs,
                                             args->num_iovs);
       if (ret) {
-      vrend_renderer_resource_destroy((struct vrend_resource *)pipe_res);
+         vrend_renderer_resource_destroy((struct vrend_resource *)blob.u.pipe_resource);
          return ret;
       }
+   }
+
+   if (ctx->get_blob_done)
+      ctx->get_blob_done(ctx, args->res_handle, &blob);
 
    return 0;
 }

src/vrend_decode.c

@@ -1502,6 +1502,20 @@ static int vrend_decode_ctx_transfer_3d(struct virgl_context *ctx,
                                       transfer_mode);
 }
 
+static int vrend_decode_ctx_get_blob(struct virgl_context *ctx,
+                                     uint64_t blob_id,
+                                     UNUSED uint32_t blob_flags,
+                                     struct virgl_context_blob *blob)
+{
+   struct vrend_decode_ctx *dctx = (struct vrend_decode_ctx *)ctx;
+
+   blob->type = VIRGL_RESOURCE_FD_INVALID;
+   /* this transfers ownership and blob_id is no longer valid */
+   blob->u.pipe_resource = vrend_get_blob_pipe(dctx->grctx, blob_id);
+
+   return blob->u.pipe_resource ? 0 : EINVAL;
+}
+
 static int vrend_decode_ctx_submit_cmd(struct virgl_context *ctx,
                                        const void *buffer,
                                        size_t size)
@@ -1694,13 +1708,6 @@ static int vrend_decode_ctx_submit_cmd(struct virgl_context *ctx,
    return ret;
 }
 
-static struct pipe_resource *vrend_decode_get_blob_pipe(struct virgl_context *ctx,
-                                                        uint64_t blob_id)
-{
-   struct vrend_decode_ctx *dctx = (struct vrend_decode_ctx *)ctx;
-   return vrend_get_blob_pipe(dctx->grctx, blob_id);
-}
-
 static void vrend_decode_ctx_init_base(struct vrend_decode_ctx *dctx,
                                        uint32_t ctx_id)
 {
@@ -1711,8 +1718,9 @@ static void vrend_decode_ctx_init_base(struct vrend_decode_ctx *dctx,
    ctx->attach_resource = vrend_decode_ctx_attach_resource;
    ctx->detach_resource = vrend_decode_ctx_detach_resource;
    ctx->transfer_3d = vrend_decode_ctx_transfer_3d;
+   ctx->get_blob = vrend_decode_ctx_get_blob;
+   ctx->get_blob_done = NULL;
    ctx->submit_cmd = vrend_decode_ctx_submit_cmd;
-   ctx->get_blob_pipe = vrend_decode_get_blob_pipe;
 }
 
 void vrend_decode_reset(void)