virtio-gpu: Add virtio_gpu_resource_create_blob

This API allows Qemu to register the blob allocated by the Guest
as a new resource and map its backing storage.

Based-on-patch-by: Gerd Hoffmann <kraxel@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Message-Id: <20210526231429.1045476-10-vivek.kasireddy@intel.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

hw/display/trace-events

@@ -32,6 +32,7 @@ virtio_gpu_cmd_get_edid(uint32_t scanout) "scanout %d"
 virtio_gpu_cmd_set_scanout(uint32_t id, uint32_t res, uint32_t w, uint32_t h, uint32_t x, uint32_t y) "id %d, res 0x%x, w %d, h %d, x %d, y %d"
 virtio_gpu_cmd_res_create_2d(uint32_t res, uint32_t fmt, uint32_t w, uint32_t h) "res 0x%x, fmt 0x%x, w %d, h %d"
 virtio_gpu_cmd_res_create_3d(uint32_t res, uint32_t fmt, uint32_t w, uint32_t h, uint32_t d) "res 0x%x, fmt 0x%x, w %d, h %d, d %d"
+virtio_gpu_cmd_res_create_blob(uint32_t res, uint64_t size) "res 0x%x, size %" PRId64
 virtio_gpu_cmd_res_unref(uint32_t res) "res 0x%x"
 virtio_gpu_cmd_res_back_attach(uint32_t res) "res 0x%x"
 virtio_gpu_cmd_res_back_detach(uint32_t res) "res 0x%x"

hw/display/virtio-gpu.c

@@ -137,7 +137,7 @@ virtio_gpu_find_check_resource(VirtIOGPU *g, uint32_t resource_id,
     }
 
     if (require_backing) {
-        if (!res->iov || !res->image) {
+        if (!res->iov || (!res->image && !res->blob)) {
             qemu_log_mask(LOG_GUEST_ERROR, "%s: no backing storage %d\n",
                           caller, resource_id);
             if (error) {
@@ -313,6 +313,62 @@ static void virtio_gpu_resource_create_2d(VirtIOGPU *g,
     g->hostmem += res->hostmem;
 }
 
+static void virtio_gpu_resource_create_blob(VirtIOGPU *g,
+                                            struct virtio_gpu_ctrl_command *cmd)
+{
+    struct virtio_gpu_simple_resource *res;
+    struct virtio_gpu_resource_create_blob cblob;
+    int ret;
+
+    VIRTIO_GPU_FILL_CMD(cblob);
+    virtio_gpu_create_blob_bswap(&cblob);
+    trace_virtio_gpu_cmd_res_create_blob(cblob.resource_id, cblob.size);
+
+    if (cblob.resource_id == 0) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: resource id 0 is not allowed\n",
+                      __func__);
+        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
+        return;
+    }
+
+    res = virtio_gpu_find_resource(g, cblob.resource_id);
+    if (res) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: resource already exists %d\n",
+                      __func__, cblob.resource_id);
+        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
+        return;
+    }
+
+    res = g_new0(struct virtio_gpu_simple_resource, 1);
+    res->resource_id = cblob.resource_id;
+    res->blob_size = cblob.size;
+
+    if (cblob.blob_mem != VIRTIO_GPU_BLOB_MEM_GUEST &&
+        cblob.blob_flags != VIRTIO_GPU_BLOB_FLAG_USE_SHAREABLE) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid memory type\n",
+                      __func__);
+        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_PARAMETER;
+        g_free(res);
+        return;
+    }
+
+    if (res->iov) {
+        cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
+        return;
+    }
+
+    ret = virtio_gpu_create_mapping_iov(g, cblob.nr_entries, sizeof(cblob),
+                                        cmd, &res->addrs, &res->iov,
+                                        &res->iov_cnt);
+    if (ret != 0) {
+        cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
+        return;
+    }
+
+    virtio_gpu_init_udmabuf(res);
+    QTAILQ_INSERT_HEAD(&g->reslist, res, next);
+}
+
 static void virtio_gpu_disable_scanout(VirtIOGPU *g, int scanout_id)
 {
     struct virtio_gpu_scanout *scanout = &g->parent_obj.scanout[scanout_id];
@@ -390,7 +446,7 @@ static void virtio_gpu_transfer_to_host_2d(VirtIOGPU *g,
 
     res = virtio_gpu_find_check_resource(g, t2d.resource_id, true,
                                          __func__, &cmd->error);
-    if (!res) {
+    if (!res || res->blob) {
         return;
     }
 
@@ -446,7 +502,7 @@ static void virtio_gpu_resource_flush(VirtIOGPU *g,
 
     res = virtio_gpu_find_check_resource(g, rf.resource_id, false,
                                          __func__, &cmd->error);
-    if (!res) {
+    if (!res || res->blob) {
         return;
     }
 
@@ -715,6 +771,10 @@ static void virtio_gpu_cleanup_mapping(VirtIOGPU *g,
     res->iov_cnt = 0;
     g_free(res->addrs);
     res->addrs = NULL;
+
+    if (res->blob) {
+        virtio_gpu_fini_udmabuf(res);
+    }
 }
 
 static void
@@ -785,6 +845,13 @@ void virtio_gpu_simple_process_cmd(VirtIOGPU *g,
     case VIRTIO_GPU_CMD_RESOURCE_CREATE_2D:
         virtio_gpu_resource_create_2d(g, cmd);
         break;
+    case VIRTIO_GPU_CMD_RESOURCE_CREATE_BLOB:
+        if (!virtio_gpu_blob_enabled(g->parent_obj.conf)) {
+            cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_PARAMETER;
+            break;
+        }
+        virtio_gpu_resource_create_blob(g, cmd);
+        break;
     case VIRTIO_GPU_CMD_RESOURCE_UNREF:
         virtio_gpu_resource_unref(g, cmd);
         break;

include/hw/virtio/virtio-gpu-bswap.h

@@ -59,4 +59,13 @@ virtio_gpu_t2d_bswap(struct virtio_gpu_transfer_to_host_2d *t2d)
     le32_to_cpus(&t2d->padding);
 }
 
+static inline void
+virtio_gpu_create_blob_bswap(struct virtio_gpu_resource_create_blob *cblob)
+{
+    virtio_gpu_ctrl_hdr_bswap(&cblob->hdr);
+    le32_to_cpus(&cblob->resource_id);
+    le32_to_cpus(&cblob->blob_flags);
+    le64_to_cpus(&cblob->size);
+}
+
 #endif