Re: [PATCH v2 5/8] vsock/virtio: Add vsock helper for linear SKB allocation

[Will Deacon <will@kernel.org>]

On Wed, Jul 02, 2025 at 06:40:17PM +0200, Stefano Garzarella wrote:
> On Tue, Jul 01, 2025 at 05:45:04PM +0100, Will Deacon wrote:
> > In preparation for nonlinear allocations for large SKBs, introduce a
> > new virtio_vsock_alloc_linear_skb() helper to return linear SKBs
> > unconditionally and switch all callers over to this new interface for
> > now.
> > 
> > No functional change.
> > 
> > Signed-off-by: Will Deacon <will@kernel.org>
> > ---
> > drivers/vhost/vsock.c                   | 2 +-
> > include/linux/virtio_vsock.h            | 6 ++++++
> > net/vmw_vsock/virtio_transport.c        | 2 +-
> > net/vmw_vsock/virtio_transport_common.c | 2 +-
> > 4 files changed, 9 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
> > index 66a0f060770e..b13f6be452ba 100644
> > --- a/drivers/vhost/vsock.c
> > +++ b/drivers/vhost/vsock.c
> > @@ -348,7 +348,7 @@ vhost_vsock_alloc_skb(struct vhost_virtqueue *vq,
> > 		return NULL;
> > 
> > 	/* len contains both payload and hdr */
> > -	skb = virtio_vsock_alloc_skb(len, GFP_KERNEL);
> > +	skb = virtio_vsock_alloc_linear_skb(len, GFP_KERNEL);
> > 	if (!skb)
> > 		return NULL;
> > 
> > diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
> > index 1b5731186095..6d4a933c895a 100644
> > --- a/include/linux/virtio_vsock.h
> > +++ b/include/linux/virtio_vsock.h
> > @@ -70,6 +70,12 @@ static inline struct sk_buff *virtio_vsock_alloc_skb(unsigned int size, gfp_t ma
> > 	return skb;
> > }
> > 
> > +static inline struct sk_buff *
> > +virtio_vsock_alloc_linear_skb(unsigned int size, gfp_t mask)
> > +{
> > +	return virtio_vsock_alloc_skb(size, mask);
> 
> Why not just renaming virtio_vsock_alloc_skb in this patch?
> 
> In that way we are sure when building this patch we don't leave any "old"
> virtio_vsock_alloc_skb() around.

We'll be bringing virtio_vsock_alloc_skb() back almost immediately, but
I can do that if you like.

Will