On Thu, Jul 11, 2024 at 04:58:46PM GMT, Luigi Leonardi via B4 Relay wrote:
From: Marco Pinna <marco.pinn95@xxxxxxxxx> 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@xxxxxxxxxxx> Signed-off-by: Luigi Leonardi <luigi.leonardi@xxxxxxxxxxx> Signed-off-by: Marco Pinna <marco.pinn95@xxxxxxxxx> --- net/vmw_vsock/virtio_transport.c | 105 ++++++++++++++++++++++----------------- 1 file changed, 59 insertions(+), 46 deletions(-)
LGTM Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.cindex 43d405298857..c4205c22f40b 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -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; -- 2.45.2
