gfxstream: guest: support blobCmd + blobCmdSize

This is useful for trying to hook into gfxstream's
ColorBuffer handlers, without creating shadow guest
memory associated with RESOURCE_CREATE_3D.

Reviewed-by: Aaron Ruby <aruby@blackberry.com>
Acked-by: Yonggang Luo <luoyonggang@gmail.com>
Acked-by: Adam Jackson <ajax@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27246>

src/gfxstream/guest/platform/include/VirtGpu.h

@@ -117,6 +117,9 @@ struct VirtGpuCreateBlob {
     enum VirtGpuResourceFlags flags;
     enum VirtGpuResourceMem blobMem;
     uint64_t blobId;
+
+    uint8_t* blobCmd;
+    uint32_t blobCmdSize;
 };
 
 struct VirtGpuCaps {

src/gfxstream/guest/platform/linux/LinuxVirtGpuDevice.cpp

@@ -184,6 +184,8 @@ VirtGpuResourcePtr LinuxVirtGpuDevice::createBlob(const struct VirtGpuCreateBlob
     create.blob_mem = blobCreate.blobMem;
     create.blob_flags = blobCreate.flags;
     create.blob_id = blobCreate.blobId;
+    create.cmd = (uint64_t)(uintptr_t)blobCreate.blobCmd;
+    create.cmd_size = blobCreate.blobCmdSize;
 
     ret = drmIoctl(mDeviceHandle, DRM_IOCTL_VIRTGPU_RESOURCE_CREATE_BLOB, &create);
     if (ret < 0) {