[1/3] hw/virtio: Document virtio_queue_packed_empty_rcu is called within RCU

Commit Message

Philippe Mathieu-Daudé Aug. 26, 2021, 5:26 p.m. UTC

While virtio_queue_packed_empty_rcu() uses the '_rcu' suffix,
it is not obvious it is called within rcu_read_lock(). All other
functions from this file called with the RCU locked have a comment
describing it. Document this one similarly for consistency.

Signed-off-by: Philippe Mathieu-Daudé <[e-mail]>
---
 hw/virtio/virtio.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Stefano Garzarella Sept. 1, 2021, 3:56 p.m. UTC | #1

On Thu, Aug 26, 2021 at 07:26:56PM +0200, Philippe Mathieu-Daudé wrote:
>While virtio_queue_packed_empty_rcu() uses the '_rcu' suffix,
>it is not obvious it is called within rcu_read_lock(). All other
>functions from this file called with the RCU locked have a comment
>describing it. Document this one similarly for consistency.
>
>Signed-off-by: Philippe Mathieu-Daudé <[e-mail]>
>---
> hw/virtio/virtio.c | 1 +
> 1 file changed, 1 insertion(+)
>
>diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
>index 874377f37a7..a5214bca612 100644
>--- a/hw/virtio/virtio.c
>+++ b/hw/virtio/virtio.c
>@@ -634,6 +634,7 @@ static int virtio_queue_split_empty(VirtQueue *vq)
>     return empty;
> }
>
>+/* Called within rcu_read_lock().  */
> static int virtio_queue_packed_empty_rcu(VirtQueue *vq)
> {
>     struct VRingPackedDesc desc;
>-- 
>2.31.1
>
>

Reviewed-by: Stefano Garzarella <[e-mail]>

Stefan Hajnoczi Sept. 2, 2021, 12:07 p.m. UTC | #2

On Thu, Aug 26, 2021 at 07:26:56PM +0200, Philippe Mathieu-Daudé wrote:
> While virtio_queue_packed_empty_rcu() uses the '_rcu' suffix,
> it is not obvious it is called within rcu_read_lock(). All other
> functions from this file called with the RCU locked have a comment
> describing it. Document this one similarly for consistency.
> 
> Signed-off-by: Philippe Mathieu-Daudé <[e-mail]>
> ---
>  hw/virtio/virtio.c | 1 +
>  1 file changed, 1 insertion(+)

Reviewed-by: Stefan Hajnoczi <[e-mail]>

Patch

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 874377f37a7..a5214bca612 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -634,6 +634,7 @@  static int virtio_queue_split_empty(VirtQueue *vq)
     return empty;
 }
 
+/* Called within rcu_read_lock().  */
 static int virtio_queue_packed_empty_rcu(VirtQueue *vq)
 {
     struct VRingPackedDesc desc;