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

Will Deacon posted 8 patches 5 months, 2 weeks ago
There is a newer version of this series
[PATCH v2 5/8] vsock/virtio: Add vsock helper for linear SKB allocation
Posted by Will Deacon 5 months, 2 weeks ago 
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);
+}
+
 static inline void
 virtio_vsock_skb_queue_head(struct sk_buff_head *list, struct sk_buff *skb)
 {
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index 3daba06ed499..2959db0404ed 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -321,7 +321,7 @@ static void virtio_vsock_rx_fill(struct virtio_vsock *vsock)
 	vq = vsock->vqs[VSOCK_VQ_RX];
 
 	do {
-		skb = virtio_vsock_alloc_skb(total_len, GFP_KERNEL);
+		skb = virtio_vsock_alloc_linear_skb(total_len, GFP_KERNEL);
 		if (!skb)
 			break;
 
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 1b5d9896edae..c9eb7f7ac00d 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -261,7 +261,7 @@ static struct sk_buff *virtio_transport_alloc_skb(struct virtio_vsock_pkt_info *
 	if (!zcopy)
 		skb_len += payload_len;
 
-	skb = virtio_vsock_alloc_skb(skb_len, GFP_KERNEL);
+	skb = virtio_vsock_alloc_linear_skb(skb_len, GFP_KERNEL);
 	if (!skb)
 		return NULL;
 
-- 
2.50.0.727.gbf7dc18ff4-goog
Re: [PATCH v2 5/8] vsock/virtio: Add vsock helper for linear SKB allocation
Posted by Stefano Garzarella 5 months, 2 weeks ago 
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.

Thanks,
Stefano

>+}
>+
> static inline void
> virtio_vsock_skb_queue_head(struct sk_buff_head *list, struct sk_buff *skb)
> {
>diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
>index 3daba06ed499..2959db0404ed 100644
>--- a/net/vmw_vsock/virtio_transport.c
>+++ b/net/vmw_vsock/virtio_transport.c
>@@ -321,7 +321,7 @@ static void virtio_vsock_rx_fill(struct virtio_vsock *vsock)
> 	vq = vsock->vqs[VSOCK_VQ_RX];
>
> 	do {
>-		skb = virtio_vsock_alloc_skb(total_len, GFP_KERNEL);
>+		skb = virtio_vsock_alloc_linear_skb(total_len, GFP_KERNEL);
> 		if (!skb)
> 			break;
>
>diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
>index 1b5d9896edae..c9eb7f7ac00d 100644
>--- a/net/vmw_vsock/virtio_transport_common.c
>+++ b/net/vmw_vsock/virtio_transport_common.c
>@@ -261,7 +261,7 @@ static struct sk_buff *virtio_transport_alloc_skb(struct virtio_vsock_pkt_info *
> 	if (!zcopy)
> 		skb_len += payload_len;
>
>-	skb = virtio_vsock_alloc_skb(skb_len, GFP_KERNEL);
>+	skb = virtio_vsock_alloc_linear_skb(skb_len, GFP_KERNEL);
> 	if (!skb)
> 		return NULL;
>
>-- 
>2.50.0.727.gbf7dc18ff4-goog
>
Re: [PATCH v2 5/8] vsock/virtio: Add vsock helper for linear SKB allocation
Posted by Will Deacon 5 months ago 
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

Patchew 2.1-devel-b67e4c2

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