On Fri, Apr 03, 2026 at 06:38:04PM +0200, Laurent Vivier wrote:
Every caller of vu_flush() was calling vu_set_vnethdr() beforehand with the same pattern. Move it into vu_flush().
Remove vu_queue_notify() from vu_flush() and let callers invoke it explicitly. This allows paths that perform multiple flushes, such as tcp_vu_send_flag() and tcp_vu_data_from_sock(), to issue a single guest notification at the end.
Signed-off-by: Laurent Vivier
Reviewed-by: David Gibson
--- tcp_vu.c | 19 ++++++++----------- udp_vu.c | 3 +-- vu_common.c | 9 +++++---- vu_common.h | 1 - 4 files changed, 14 insertions(+), 18 deletions(-)
diff --git a/tcp_vu.c b/tcp_vu.c index dc0e17c0f03f..0cd01190d612 100644 --- a/tcp_vu.c +++ b/tcp_vu.c @@ -82,7 +82,6 @@ int tcp_vu_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags) struct ethhdr *eh; uint32_t seq; int elem_cnt; - int nb_ack; int ret;
hdrlen = tcp_vu_hdrlen(CONN_V6(conn)); @@ -97,8 +96,6 @@ int tcp_vu_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags) assert(flags_elem[0].in_sg[0].iov_len >= MAX(hdrlen + sizeof(*opts), ETH_ZLEN + VNET_HLEN));
- vu_set_vnethdr(flags_elem[0].in_sg[0].iov_base, 1); - eh = vu_eth(flags_elem[0].in_sg[0].iov_base);
memcpy(eh->h_dest, c->guest_mac, sizeof(eh->h_dest)); @@ -143,9 +140,10 @@ int tcp_vu_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags) l2len = optlen + hdrlen - VNET_HLEN; vu_pad(&flags_elem[0].in_sg[0], l2len);
+ vu_flush(vdev, vq, flags_elem, 1); + if (*c->pcap) pcap_iov(&flags_elem[0].in_sg[0], 1, VNET_HLEN); - nb_ack = 1;
if (flags & DUP_ACK) { elem_cnt = vu_collect(vdev, vq, &flags_elem[1], 1, @@ -157,14 +155,14 @@ int tcp_vu_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags) memcpy(flags_elem[1].in_sg[0].iov_base, flags_elem[0].in_sg[0].iov_base, flags_elem[0].in_sg[0].iov_len); - nb_ack++; + + vu_flush(vdev, vq, &flags_elem[1], 1);
if (*c->pcap) pcap_iov(&flags_elem[1].in_sg[0], 1, VNET_HLEN); } } - - vu_flush(vdev, vq, flags_elem, nb_ack); + vu_queue_notify(vdev, vq);
return 0; } @@ -451,7 +449,6 @@ int tcp_vu_data_from_sock(const struct ctx *c, struct tcp_tap_conn *conn) assert(frame_size >= hdrlen);
dlen = frame_size - hdrlen; - vu_set_vnethdr(iov->iov_base, buf_cnt);
/* The IPv4 header checksum varies only with dlen */ if (previous_dlen != dlen) @@ -464,14 +461,14 @@ int tcp_vu_data_from_sock(const struct ctx *c, struct tcp_tap_conn *conn) l2len = dlen + hdrlen - VNET_HLEN; vu_pad(iov, l2len);
+ vu_flush(vdev, vq, &elem[head[i]], buf_cnt); + if (*c->pcap) pcap_iov(iov, buf_cnt, VNET_HLEN);
conn->seq_to_tap += dlen; } - - /* send packets */ - vu_flush(vdev, vq, elem, iov_cnt); + vu_queue_notify(vdev, vq);
conn_flag(c, conn, ACK_FROM_TAP_DUE);
diff --git a/udp_vu.c b/udp_vu.c index cc69654398f0..f8629af58ab5 100644 --- a/udp_vu.c +++ b/udp_vu.c @@ -124,8 +124,6 @@ static int udp_vu_sock_recv(const struct ctx *c, struct vu_virtq *vq, int s, l2len = *dlen + hdrlen - VNET_HLEN; vu_pad(&iov_vu[0], l2len);
- vu_set_vnethdr(iov_vu[0].iov_base, elem_used); - /* release unused buffers */ vu_queue_rewind(vq, elem_cnt - elem_used);
@@ -230,6 +228,7 @@ void udp_vu_sock_to_tap(const struct ctx *c, int s, int n, flow_sidx_t tosidx) pcap_iov(iov_vu, iov_used, VNET_HLEN); } vu_flush(vdev, vq, elem, iov_used); + vu_queue_notify(vdev, vq); } } } diff --git a/vu_common.c b/vu_common.c index 13b1e51001d4..57949ca32309 100644 --- a/vu_common.c +++ b/vu_common.c @@ -118,7 +118,8 @@ int vu_collect(const struct vu_dev *vdev, struct vu_virtq *vq, * @vnethdr: Address of the header to set * @num_buffers: Number of guest buffers of the frame */ -void vu_set_vnethdr(struct virtio_net_hdr_mrg_rxbuf *vnethdr, int num_buffers) +static void vu_set_vnethdr(struct virtio_net_hdr_mrg_rxbuf *vnethdr, + int num_buffers) { vnethdr->hdr = VU_HEADER; /* Note: if VIRTIO_NET_F_MRG_RXBUF is not negotiated, @@ -139,6 +140,8 @@ void vu_flush(const struct vu_dev *vdev, struct vu_virtq *vq, { int i;
+ vu_set_vnethdr(elem[0].in_sg[0].iov_base, elem_cnt); + for (i = 0; i < elem_cnt; i++) { size_t elem_size = iov_size(elem[i].in_sg, elem[i].in_num);
@@ -146,7 +149,6 @@ void vu_flush(const struct vu_dev *vdev, struct vu_virtq *vq, }
vu_queue_flush(vdev, vq, elem_cnt); - vu_queue_notify(vdev, vq); }
/** @@ -260,8 +262,6 @@ int vu_send_single(const struct ctx *c, const void *buf, size_t size) goto err; }
- vu_set_vnethdr(in_sg[0].iov_base, elem_cnt); - total -= VNET_HLEN;
/* copy data from the buffer to the iovec */ @@ -271,6 +271,7 @@ int vu_send_single(const struct ctx *c, const void *buf, size_t size) pcap_iov(in_sg, in_total, VNET_HLEN);
vu_flush(vdev, vq, elem, elem_cnt); + vu_queue_notify(vdev, vq);
trace("vhost-user sent %zu", total);
diff --git a/vu_common.h b/vu_common.h index 7b060eb6184f..4037ab765b7d 100644 --- a/vu_common.h +++ b/vu_common.h @@ -39,7 +39,6 @@ int vu_collect(const struct vu_dev *vdev, struct vu_virtq *vq, struct vu_virtq_element *elem, int max_elem, struct iovec *in_sg, size_t max_in_sg, size_t *in_total, size_t size, size_t *collected); -void vu_set_vnethdr(struct virtio_net_hdr_mrg_rxbuf *vnethdr, int num_buffers); void vu_flush(const struct vu_dev *vdev, struct vu_virtq *vq, struct vu_virtq_element *elem, int elem_cnt); void vu_kick_cb(struct vu_dev *vdev, union epoll_ref ref, -- 2.53.0
-- David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson