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vsock/virtio: refactor virtio_transport_send_pkt_work

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Preliminary patch to introduce an optimization to the
enqueue system.

All the code used to enqueue a packet into the virtqueue
is removed from virtio_transport_send_pkt_work()
and moved to the new virtio_transport_send_skb() function.

Co-developed-by: Luigi Leonardi <luigi.leonardi@outlook.com>
Signed-off-by: Luigi Leonardi <luigi.leonardi@outlook.com>
Signed-off-by: Marco Pinna <marco.pinn95@gmail.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20240730-pinna-v4-1-5c9179164db5@outlook.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Marco Pinna 2024-07-30 21:47:31 +02:00 committed by Michael S. Tsirkin
parent 4a21d31d7b
commit 26618da3b2
1 changed files with 59 additions and 46 deletions
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105
net/vmw_vsock/virtio_transport.c
View file

@ -94,6 +94,63 @@ static u32 virtio_transport_get_local_cid(void)
return ret;
}
/* Caller need to hold vsock->tx_lock on vq */
static int virtio_transport_send_skb(struct sk_buff *skb, struct virtqueue *vq,
struct virtio_vsock *vsock)
{
int ret, in_sg = 0, out_sg = 0;
struct scatterlist **sgs;
sgs = vsock->out_sgs;
sg_init_one(sgs[out_sg], virtio_vsock_hdr(skb),
sizeof(*virtio_vsock_hdr(skb)));
out_sg++;
if (!skb_is_nonlinear(skb)) {
if (skb->len > 0) {
sg_init_one(sgs[out_sg], skb->data, skb->len);
out_sg++;
}
} else {
struct skb_shared_info *si;
int i;
/* If skb is nonlinear, then its buffer must contain
* only header and nothing more. Data is stored in
* the fragged part.
*/
WARN_ON_ONCE(skb_headroom(skb) != sizeof(*virtio_vsock_hdr(skb)));
si = skb_shinfo(skb);
for (i = 0; i < si->nr_frags; i++) {
skb_frag_t *skb_frag = &si->frags[i];
void *va;
/* 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_page(skb_frag));
sg_init_one(sgs[out_sg],
va + skb_frag_off(skb_frag),
skb_frag_size(skb_frag));
out_sg++;
}
}
ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, skb, GFP_KERNEL);
/* Usually this means that there is no more space available in
* the vq
*/
if (ret < 0)
return ret;
virtio_transport_deliver_tap_pkt(skb);
return 0;
}
static void
virtio_transport_send_pkt_work(struct work_struct *work)
{
@ -111,66 +168,22 @@ virtio_transport_send_pkt_work(struct work_struct *work)
vq = vsock->vqs[VSOCK_VQ_TX];
for (;;) {
int ret, in_sg = 0, out_sg = 0;
struct scatterlist **sgs;
struct sk_buff *skb;
bool reply;
int ret;
skb = virtio_vsock_skb_dequeue(&vsock->send_pkt_queue);
if (!skb)
break;
reply = virtio_vsock_skb_reply(skb);
sgs = vsock->out_sgs;
sg_init_one(sgs[out_sg], virtio_vsock_hdr(skb),
sizeof(*virtio_vsock_hdr(skb)));
out_sg++;
if (!skb_is_nonlinear(skb)) {
if (skb->len > 0) {
sg_init_one(sgs[out_sg], skb->data, skb->len);
out_sg++;
}
} else {
struct skb_shared_info *si;
int i;
/* If skb is nonlinear, then its buffer must contain
* only header and nothing more. Data is stored in
* the fragged part.
*/
WARN_ON_ONCE(skb_headroom(skb) != sizeof(*virtio_vsock_hdr(skb)));
si = skb_shinfo(skb);
for (i = 0; i < si->nr_frags; i++) {
skb_frag_t *skb_frag = &si->frags[i];
void *va;
/* 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_page(skb_frag));
sg_init_one(sgs[out_sg],
va + skb_frag_off(skb_frag),
skb_frag_size(skb_frag));
out_sg++;
}
}
ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, skb, GFP_KERNEL);
/* Usually this means that there is no more space available in
* the vq
*/
ret = virtio_transport_send_skb(skb, vq, vsock);
if (ret < 0) {
virtio_vsock_skb_queue_head(&vsock->send_pkt_queue, skb);
break;
}
virtio_transport_deliver_tap_pkt(skb);
if (reply) {
struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
int val;