A little typo in the title: s/EAGIAN/EAGAIN
Thanks,
Stefano
On Wed, Jul 31, 2019 at 04:46:55AM -0400, Jason Wang wrote:
> Instead of returning -EAGAIN unconditionally, we'd better do that only
> we're sure the range is overlapped with the metadata area.
>
> Reported-by: Jason Gunthorpe <jgg@xxxxxxxx>
> Fixes: 7f466032dc9e ("vhost: access vq metadata through kernel virtual address")
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> ---
> drivers/vhost/vhost.c | 32 +++++++++++++++++++-------------
> 1 file changed, 19 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index fc2da8a0c671..96c6aeb1871f 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -399,16 +399,19 @@ static void inline vhost_vq_sync_access(struct vhost_virtqueue *vq)
> smp_mb();
> }
>
> -static void vhost_invalidate_vq_start(struct vhost_virtqueue *vq,
> - int index,
> - unsigned long start,
> - unsigned long end)
> +static int vhost_invalidate_vq_start(struct vhost_virtqueue *vq,
> + int index,
> + unsigned long start,
> + unsigned long end,
> + bool blockable)
> {
> struct vhost_uaddr *uaddr = &vq->uaddrs[index];
> struct vhost_map *map;
>
> if (!vhost_map_range_overlap(uaddr, start, end))
> - return;
> + return 0;
> + else if (!blockable)
> + return -EAGAIN;
>
> spin_lock(&vq->mmu_lock);
> ++vq->invalidate_count;
> @@ -423,6 +426,8 @@ static void vhost_invalidate_vq_start(struct vhost_virtqueue *vq,
> vhost_set_map_dirty(vq, map, index);
> vhost_map_unprefetch(map);
> }
> +
> + return 0;
> }
>
> static void vhost_invalidate_vq_end(struct vhost_virtqueue *vq,
> @@ -443,18 +448,19 @@ static int vhost_invalidate_range_start(struct mmu_notifier *mn,
> {
> struct vhost_dev *dev = container_of(mn, struct vhost_dev,
> mmu_notifier);
> - int i, j;
> -
> - if (!mmu_notifier_range_blockable(range))
> - return -EAGAIN;
> + bool blockable = mmu_notifier_range_blockable(range);
> + int i, j, ret;
>
> for (i = 0; i < dev->nvqs; i++) {
> struct vhost_virtqueue *vq = dev->vqs[i];
>
> - for (j = 0; j < VHOST_NUM_ADDRS; j++)
> - vhost_invalidate_vq_start(vq, j,
> - range->start,
> - range->end);
> + for (j = 0; j < VHOST_NUM_ADDRS; j++) {
> + ret = vhost_invalidate_vq_start(vq, j,
> + range->start,
> + range->end, blockable);
> + if (ret)
> + return ret;
> + }
> }
>
> return 0;
> --
> 2.18.1
>
--
