[v3] Abstract page from net stack

[PATCH net-next v3 1/3] vsock/virtio: use skb_frag_*() helpers

Posted by Mina Almasry 1 year, 12 months ago

Minor fix for virtio: code wanting to access the fields inside an skb
frag should use the skb_frag_*() helpers, instead of accessing the
fields directly. This allows for extensions where the underlying
memory is not a page.

Signed-off-by: Mina Almasry <almasrymina@google.com>

---

v2:

- Also fix skb_frag_off() + skb_frag_size() (David)
- Did not apply the reviewed-by from Stefano since the patch changed
relatively much.

---
 net/vmw_vsock/virtio_transport.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index f495b9e5186b..1748268e0694 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -153,10 +153,10 @@ virtio_transport_send_pkt_work(struct work_struct *work)
 				 * 'virt_to_phys()' later to fill the buffer descriptor.
 				 * We don't touch memory at "virtual" address of this page.
 				 */
-				va = page_to_virt(skb_frag->bv_page);
+				va = page_to_virt(skb_frag_page(skb_frag));
 				sg_init_one(sgs[out_sg],
-					    va + skb_frag->bv_offset,
-					    skb_frag->bv_len);
+					    va + skb_frag_off(skb_frag),
+					    skb_frag_size(skb_frag));
 				out_sg++;
 			}
 		}
-- 
2.43.0.472.g3155946c3a-goog

Re: [PATCH net-next v3 1/3] vsock/virtio: use skb_frag_*() helpers

Posted by Stefano Garzarella 1 year, 11 months ago

On Wed, Dec 20, 2023 at 01:45:00PM -0800, Mina Almasry wrote:
>Minor fix for virtio: code wanting to access the fields inside an skb
>frag should use the skb_frag_*() helpers, instead of accessing the
>fields directly. This allows for extensions where the underlying
>memory is not a page.
>
>Signed-off-by: Mina Almasry <almasrymina@google.com>
>
>---
>
>v2:
>
>- Also fix skb_frag_off() + skb_frag_size() (David)
>- Did not apply the reviewed-by from Stefano since the patch changed
>relatively much.

Sorry for the delay, I was off.

LGTM!

Acked-by: Stefano Garzarella <sgarzare@redhat.com>

Possibly we can also send this patch alone if the series is still under
discussion because it's definitely an improvement to the current code.

Thanks,
Stefano

>
>---
> net/vmw_vsock/virtio_transport.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
>diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
>index f495b9e5186b..1748268e0694 100644
>--- a/net/vmw_vsock/virtio_transport.c
>+++ b/net/vmw_vsock/virtio_transport.c
>@@ -153,10 +153,10 @@ virtio_transport_send_pkt_work(struct work_struct *work)
> 				 * 'virt_to_phys()' later to fill the buffer descriptor.
> 				 * We don't touch memory at "virtual" address of this page.
> 				 */
>-				va = page_to_virt(skb_frag->bv_page);
>+				va = page_to_virt(skb_frag_page(skb_frag));
> 				sg_init_one(sgs[out_sg],
>-					    va + skb_frag->bv_offset,
>-					    skb_frag->bv_len);
>+					    va + skb_frag_off(skb_frag),
>+					    skb_frag_size(skb_frag));
> 				out_sg++;
> 			}
> 		}
>-- 
>2.43.0.472.g3155946c3a-goog
>

Re: [PATCH net-next v3 1/3] vsock/virtio: use skb_frag_*() helpers

Posted by Shakeel Butt 1 year, 12 months ago

On Wed, Dec 20, 2023 at 1:45 PM Mina Almasry <almasrymina@google.com> wrote:
>
> Minor fix for virtio: code wanting to access the fields inside an skb
> frag should use the skb_frag_*() helpers, instead of accessing the
> fields directly. This allows for extensions where the underlying
> memory is not a page.
>
> Signed-off-by: Mina Almasry <almasrymina@google.com>

Reviewed-by: Shakeel Butt <shakeelb@google.com>

Re: [PATCH net-next v3 1/3] vsock/virtio: use skb_frag_*() helpers

Posted by Willem de Bruijn 1 year, 12 months ago

Mina Almasry wrote:
> Minor fix for virtio: code wanting to access the fields inside an skb
> frag should use the skb_frag_*() helpers, instead of accessing the
> fields directly. This allows for extensions where the underlying
> memory is not a page.
> 
> Signed-off-by: Mina Almasry <almasrymina@google.com>
> 
> ---
> 
> v2:
> 
> - Also fix skb_frag_off() + skb_frag_size() (David)
> - Did not apply the reviewed-by from Stefano since the patch changed
> relatively much.
> 
> ---
>  net/vmw_vsock/virtio_transport.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
> index f495b9e5186b..1748268e0694 100644
> --- a/net/vmw_vsock/virtio_transport.c
> +++ b/net/vmw_vsock/virtio_transport.c
> @@ -153,10 +153,10 @@ virtio_transport_send_pkt_work(struct work_struct *work)
>  				 * 'virt_to_phys()' later to fill the buffer descriptor.
>  				 * We don't touch memory at "virtual" address of this page.
>  				 */
> -				va = page_to_virt(skb_frag->bv_page);
> +				va = page_to_virt(skb_frag_page(skb_frag));
>  				sg_init_one(sgs[out_sg],
> -					    va + skb_frag->bv_offset,
> -					    skb_frag->bv_len);
> +					    va + skb_frag_off(skb_frag),
> +					    skb_frag_size(skb_frag));
>  				out_sg++;
>  			}
>  		}

If there are requests for further revision in the series, can send
this virtio cleanup on its own to get it off the stack.

> -- 
> 2.43.0.472.g3155946c3a-goog
>