vdrm+tu+fd: Make cross-device optional

Similar to commit 087e9a96d1 ("venus: make cross-device optional"),
make VIRTGPU_BLOB_FLAG_USE_CROSS_DEVICE use optional, because qemu does
not support this.

Fixes: 06e57e3231 ("virtio: Add vdrm native-context helper")
Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32392>
(cherry picked from commit dfd519ed80)

.pick_status.json

@@ -1694,7 +1694,7 @@
         "description": "vdrm+tu+fd: Make cross-device optional",
         "nominated": true,
         "nomination_type": 2,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": "06e57e32310f51e752d7798e287400e8edc10312",
         "notes": null

src/freedreno/drm/virtio/virtio_bo.c

@@ -316,8 +316,9 @@ virtio_bo_new(struct fd_device *dev, uint32_t size, uint32_t flags)
 
    uint32_t blob_flags = 0;
    if (flags & (FD_BO_SHARED | FD_BO_SCANOUT)) {
-      blob_flags = VIRTGPU_BLOB_FLAG_USE_CROSS_DEVICE |
-            VIRTGPU_BLOB_FLAG_USE_SHAREABLE;
+      blob_flags = VIRTGPU_BLOB_FLAG_USE_SHAREABLE;
+      if (virtio_dev->vdrm->supports_cross_device)
+         blob_flags |= VIRTGPU_BLOB_FLAG_USE_CROSS_DEVICE;
    }
 
    if (!(flags & FD_BO_NOMAP)) {

src/freedreno/vulkan/tu_knl_drm_virtio.cc

@@ -667,8 +667,9 @@ virtio_bo_init(struct tu_device *dev,
    }
 
    if (!(mem_property & VK_MEMORY_PROPERTY_LAZILY_ALLOCATED_BIT)) {
-      blob_flags |= VIRTGPU_BLOB_FLAG_USE_CROSS_DEVICE |
-            VIRTGPU_BLOB_FLAG_USE_SHAREABLE;
+      blob_flags |= VIRTGPU_BLOB_FLAG_USE_SHAREABLE;
+      if (vdev->vdrm->supports_cross_device)
+         blob_flags |= VIRTGPU_BLOB_FLAG_USE_CROSS_DEVICE;
    }
 
    if (flags & TU_BO_ALLOC_GPU_READ_ONLY)

src/virtio/vdrm/vdrm.h

@@ -54,6 +54,7 @@ struct vdrm_device {
    const struct vdrm_device_funcs *funcs;
 
    struct virgl_renderer_capset_drm caps;
+   bool supports_cross_device;
    struct vdrm_shmem *shmem;
    uint8_t *rsp_mem;
    uint32_t rsp_mem_len;

src/virtio/vdrm/vdrm_virtgpu.c

@@ -350,6 +350,20 @@ init_shmem(struct virtgpu_device *vgdev)
    return 0;
 }
 
+static uint64_t
+get_param(int fd, uint64_t param)
+{
+   /* val must be zeroed because kernel only writes the lower 32 bits */
+   uint64_t val = 0;
+   struct drm_virtgpu_getparam args = {
+      .param = param,
+      .value = (uintptr_t)&val,
+   };
+
+   const int ret = virtgpu_ioctl(fd, VIRTGPU_GETPARAM, &args);
+   return ret ? 0 : val;
+}
+
 struct vdrm_device * vdrm_virtgpu_connect(int fd, uint32_t context_type);
 
 struct vdrm_device *
@@ -395,5 +409,12 @@ vdrm_virtgpu_connect(int fd, uint32_t context_type)
    vdev->caps = caps;
    vdev->funcs = &funcs;
 
+   /* Cross-device feature is optional.  It enables sharing dma-bufs
+    * with other virtio devices, like virtio-wl or virtio-video used
+    * by ChromeOS VMs.  Qemu doesn't support cross-device sharing.
+    */
+   if (get_param(fd, VIRTGPU_PARAM_CROSS_DEVICE))
+      vdev->supports_cross_device = true;
+
    return vdev;
 }