Rob Clark
2023-Jan-27 15:44 UTC
[PATCH] drm/virtio: exbuf->fence_fd unmodified on interrupted wait
On Fri, Jan 27, 2023 at 12:31 AM Ryan Neph <ryanneph at chromium.org> wrote:> > 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 at chromium.org>Reviewed-by: Rob Clark <robdclark at gmail.com>> --- > > 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 >