An interrupted dma_fence_wait() becomes an -ERESTARTSYS returned
to userspace ioctl(DRM_IOCTL_VIRTGPU_EXECBUFFER) calls, prompting to
retry the ioctl(), but the passed exbuf->fence_fd has been reset to -1,
making the retry attempt fail at sync_file_get_fence().
The uapi for DRM_IOCTL_VIRTGPU_EXECBUFFER is changed to retain the
passed value for exbuf->fence_fd when returning ERESTARTSYS or EINTR.
Fixes: 2cd7b6f08bc4 ("drm/virtio: add in/out fence support for explicit synchronization")
Signed-off-by: Ryan Neph <ryanneph@xxxxxxxxxxxx>
---
drivers/gpu/drm/virtio/virtgpu_ioctl.c | 9 ++++++---
include/uapi/drm/virtgpu_drm.h | 3 +++
2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index 9f4a90493aea..ffce4e2a409a 100644
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -132,6 +132,8 @@ static int virtio_gpu_execbuffer_ioctl(struct drm_device *dev, void *data,
uint64_t fence_ctx;
uint32_t ring_idx;
+ exbuf->fence_fd = -1;
+
fence_ctx = vgdev->fence_drv.context;
ring_idx = 0;
@@ -152,8 +154,6 @@ static int virtio_gpu_execbuffer_ioctl(struct drm_device *dev, void *data,
ring_idx = exbuf->ring_idx;
}
- exbuf->fence_fd = -1;
-
virtio_gpu_create_context(dev, file);
if (exbuf->flags & VIRTGPU_EXECBUF_FENCE_FD_IN) {
struct dma_fence *in_fence;
@@ -173,7 +173,7 @@ static int virtio_gpu_execbuffer_ioctl(struct drm_device *dev, void *data,
dma_fence_put(in_fence);
if (ret)
- return ret;
+ goto out_err;
}
if (exbuf->flags & VIRTGPU_EXECBUF_FENCE_FD_OUT) {
@@ -259,6 +259,9 @@ static int virtio_gpu_execbuffer_ioctl(struct drm_device *dev, void *data,
if (out_fence_fd >= 0)
put_unused_fd(out_fence_fd);
+out_err:
+ if (ret == -EINTR || ret == -ERESTARTSYS)
+ exbuf->fence_fd = in_fence_fd;
return ret;
}
diff --git a/include/uapi/drm/virtgpu_drm.h b/include/uapi/drm/virtgpu_drm.h
index 0512fde5e697..ac8d1eed12ab 100644
--- a/include/uapi/drm/virtgpu_drm.h
+++ b/include/uapi/drm/virtgpu_drm.h
@@ -64,6 +64,9 @@ struct drm_virtgpu_map {
__u32 pad;
};
+/* For ioctl() returning ERESTARTSYS or EINTR, fence_fd is unmodified.
+ * For all other errors it is set to -1.
+ */
struct drm_virtgpu_execbuffer {
__u32 flags;
__u32 size;
--
2.39.1.456.gfc5497dd1b-goog
