From: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
To: Stefan Hajnoczi <stefanha@redhat.com>,
Stefano Garzarella <sgarzare@redhat.com>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
Jason Wang <jasowang@redhat.com>,
Bobby Eshleman <bobby.eshleman@bytedance.com>
Cc: <kvm@vger.kernel.org>,
<virtualization@lists.linux-foundation.org>,
<netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<kernel@sberdevices.ru>, <oxffffaa@gmail.com>,
<avkrasnov@sberdevices.ru>,
Arseniy Krasnov <AVKrasnov@sberdevices.ru>
Subject: [PATCH net-next v3 2/4] vsock/virtio: support to send non-linear skb
Date: Fri, 21 Jul 2023 00:42:43 +0300 [thread overview]
Message-ID: <20230720214245.457298-3-AVKrasnov@sberdevices.ru> (raw)
In-Reply-To: <20230720214245.457298-1-AVKrasnov@sberdevices.ru>
For non-linear skb use its pages from fragment array as buffers in
virtio tx queue. These pages are already pinned by 'get_user_pages()'
during such skb creation.
Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
---
Changelog:
v2 -> v3:
* Comment about 'page_to_virt()' is updated. I don't remove R-b,
as this change is quiet small I guess.
net/vmw_vsock/virtio_transport.c | 41 +++++++++++++++++++++++++++-----
1 file changed, 35 insertions(+), 6 deletions(-)
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index e95df847176b..7bbcc8093e51 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -100,7 +100,9 @@ virtio_transport_send_pkt_work(struct work_struct *work)
vq = vsock->vqs[VSOCK_VQ_TX];
for (;;) {
- struct scatterlist hdr, buf, *sgs[2];
+ /* +1 is for packet header. */
+ struct scatterlist *sgs[MAX_SKB_FRAGS + 1];
+ struct scatterlist bufs[MAX_SKB_FRAGS + 1];
int ret, in_sg = 0, out_sg = 0;
struct sk_buff *skb;
bool reply;
@@ -111,12 +113,39 @@ virtio_transport_send_pkt_work(struct work_struct *work)
virtio_transport_deliver_tap_pkt(skb);
reply = virtio_vsock_skb_reply(skb);
+ sg_init_one(&bufs[out_sg], virtio_vsock_hdr(skb),
+ sizeof(*virtio_vsock_hdr(skb)));
+ sgs[out_sg] = &bufs[out_sg];
+ out_sg++;
+
+ if (!skb_is_nonlinear(skb)) {
+ if (skb->len > 0) {
+ sg_init_one(&bufs[out_sg], skb->data, skb->len);
+ sgs[out_sg] = &bufs[out_sg];
+ out_sg++;
+ }
+ } else {
+ struct skb_shared_info *si;
+ int i;
+
+ si = skb_shinfo(skb);
+
+ for (i = 0; i < si->nr_frags; i++) {
+ skb_frag_t *skb_frag = &si->frags[i];
+ void *va;
- sg_init_one(&hdr, virtio_vsock_hdr(skb), sizeof(*virtio_vsock_hdr(skb)));
- sgs[out_sg++] = &hdr;
- if (skb->len > 0) {
- sg_init_one(&buf, skb->data, skb->len);
- sgs[out_sg++] = &buf;
+ /* We will use 'page_to_virt()' for the userspace page
+ * here, because virtio or dma-mapping layers will call
+ * '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);
+ sg_init_one(&bufs[out_sg],
+ va + skb_frag->bv_offset,
+ skb_frag->bv_len);
+ sgs[out_sg] = &bufs[out_sg];
+ out_sg++;
+ }
}
ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, skb, GFP_KERNEL);
--
2.25.1
next prev parent reply other threads:[~2023-07-20 21:48 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-20 21:42 [PATCH net-next v3 0/4] vsock/virtio/vhost: MSG_ZEROCOPY preparations Arseniy Krasnov
2023-07-20 21:42 ` [PATCH net-next v3 1/4] vsock/virtio/vhost: read data from non-linear skb Arseniy Krasnov
2023-07-20 21:42 ` Arseniy Krasnov [this message]
2023-07-25 8:17 ` [PATCH net-next v3 2/4] vsock/virtio: support to send " Stefano Garzarella
2023-07-20 21:42 ` [PATCH net-next v3 3/4] vsock/virtio: non-linear skb handling for tap Arseniy Krasnov
2023-07-20 21:42 ` [PATCH net-next v3 4/4] vsock/virtio: MSG_ZEROCOPY flag support Arseniy Krasnov
2023-07-21 5:09 ` Arseniy Krasnov
2023-07-25 8:43 ` Stefano Garzarella
2023-07-25 8:46 ` Arseniy Krasnov
2023-07-25 9:16 ` Arseniy Krasnov
2023-07-25 12:28 ` Stefano Garzarella
2023-07-25 12:39 ` Michael S. Tsirkin
2023-07-25 12:45 ` Stefano Garzarella
2023-07-27 8:32 ` Arseniy Krasnov
2023-07-27 8:54 ` Stefano Garzarella
2023-07-25 11:50 ` Michael S. Tsirkin
2023-07-25 12:53 ` Stefano Garzarella
2023-07-25 13:06 ` Michael S. Tsirkin
2023-07-25 13:21 ` Stefano Garzarella
2023-07-25 13:04 ` Arseniy Krasnov
2023-07-25 13:22 ` Michael S. Tsirkin
2023-07-25 13:28 ` Arseniy Krasnov
2023-07-25 13:36 ` Michael S. Tsirkin
2023-07-25 13:35 ` Arseniy Krasnov
2023-07-25 8:25 ` Michael S. Tsirkin
2023-07-25 8:39 ` Arseniy Krasnov
2023-07-25 11:59 ` Michael S. Tsirkin
2023-07-25 13:10 ` Arseniy Krasnov
2023-07-25 13:23 ` Michael S. Tsirkin
2023-07-25 13:30 ` Arseniy Krasnov
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