On Fri, Apr 03, 2026 at 06:38:06PM +0200, Laurent Vivier wrote:
udp_vu_sock_recv(), udp_vu_prepare(), and udp_vu_csum() all operated on the file-scoped iov_vu[] array directly. Pass iov and count as explicit parameters instead, and move iov_vu[] and elem[] to function-local statics in udp_vu_sock_to_tap(), the only function that needs them.
Signed-off-by: Laurent Vivier
Reviewed-by: David Gibson
--- udp_vu.c | 64 +++++++++++++++++++++++++++++--------------------------- 1 file changed, 33 insertions(+), 31 deletions(-)
diff --git a/udp_vu.c b/udp_vu.c index 34f39e1256f8..9688fe1fdc5c 100644 --- a/udp_vu.c +++ b/udp_vu.c @@ -33,9 +33,6 @@ #include "udp_vu.h" #include "vu_common.h"
-static struct iovec iov_vu [VIRTQUEUE_MAX_SIZE]; -static struct vu_virtq_element elem [VIRTQUEUE_MAX_SIZE]; - /** * udp_vu_hdrlen() - Sum size of all headers, from UDP to virtio-net * @v6: Set for IPv6 packet @@ -58,14 +55,14 @@ static size_t udp_vu_hdrlen(bool v6)
/** * udp_vu_sock_recv() - Receive datagrams from socket into vhost-user buffers + * @iov: IO vector for the frame (in/out) + * @cnt: Number of IO vector entries (in/out)
Nit: this new description loses some details about the value of *@cnt on output.
* @s: Socket to receive from * @v6: Set for IPv6 connections - * @iov_cnt: Number of collected iov in iov_vu (input) - * Number of iov entries used to store the datagram (output) * * Return: size of received data, -1 on error */ -static ssize_t udp_vu_sock_recv(int s, bool v6, size_t *iov_cnt) +static ssize_t udp_vu_sock_recv(struct iovec *iov, size_t *cnt, int s, bool v6) { struct msghdr msg = { 0 }; size_t hdrlen, l2len; @@ -75,27 +72,27 @@ static ssize_t udp_vu_sock_recv(int s, bool v6, size_t *iov_cnt) hdrlen = udp_vu_hdrlen(v6);
/* reserve space for the headers */ - assert(iov_vu[0].iov_len >= MAX(hdrlen, ETH_ZLEN + VNET_HLEN)); - iov_vu[0].iov_base = (char *)iov_vu[0].iov_base + hdrlen; - iov_vu[0].iov_len -= hdrlen; + assert(iov[0].iov_len >= MAX(hdrlen, ETH_ZLEN + VNET_HLEN)); + iov[0].iov_base = (char *)iov[0].iov_base + hdrlen; + iov[0].iov_len -= hdrlen;
/* read data from the socket */ - msg.msg_iov = iov_vu; - msg.msg_iovlen = *iov_cnt; + msg.msg_iov = iov; + msg.msg_iovlen = *cnt;
dlen = recvmsg(s, &msg, 0); if (dlen < 0) return -1;
/* restore the pointer to the headers address */ - iov_vu[0].iov_base = (char *)iov_vu[0].iov_base - hdrlen; - iov_vu[0].iov_len += hdrlen; + iov[0].iov_base = (char *)iov[0].iov_base - hdrlen; + iov[0].iov_len += hdrlen;
- *iov_cnt = iov_truncate(iov_vu, *iov_cnt, dlen + hdrlen); + *cnt = iov_truncate(iov, *cnt, dlen + hdrlen);
/* pad frame to 60 bytes: first buffer is at least ETH_ZLEN long */ l2len = dlen + hdrlen - VNET_HLEN; - vu_pad(&iov_vu[0], l2len); + vu_pad(&iov[0], l2len);
return dlen; } @@ -103,27 +100,28 @@ static ssize_t udp_vu_sock_recv(int s, bool v6, size_t *iov_cnt) /** * udp_vu_prepare() - Prepare the packet header * @c: Execution context + * @iov: IO vector for the frame (including vnet header) * @toside: Address information for one side of the flow * @dlen: Packet data length * * Return: Layer-4 length */ -static size_t udp_vu_prepare(const struct ctx *c, +static size_t udp_vu_prepare(const struct ctx *c, const struct iovec *iov, const struct flowside *toside, ssize_t dlen) { struct ethhdr *eh; size_t l4len;
/* ethernet header */ - eh = vu_eth(iov_vu[0].iov_base); + eh = vu_eth(iov[0].iov_base);
memcpy(eh->h_dest, c->guest_mac, sizeof(eh->h_dest)); memcpy(eh->h_source, c->our_tap_mac, sizeof(eh->h_source));
/* initialize header */ if (inany_v4(&toside->eaddr) && inany_v4(&toside->oaddr)) { - struct iphdr *iph = vu_ip(iov_vu[0].iov_base); - struct udp_payload_t *bp = vu_payloadv4(iov_vu[0].iov_base); + struct iphdr *iph = vu_ip(iov[0].iov_base); + struct udp_payload_t *bp = vu_payloadv4(iov[0].iov_base);
eh->h_proto = htons(ETH_P_IP);
@@ -131,8 +129,8 @@ static size_t udp_vu_prepare(const struct ctx *c,
l4len = udp_update_hdr4(iph, bp, toside, dlen, true); } else { - struct ipv6hdr *ip6h = vu_ip(iov_vu[0].iov_base); - struct udp_payload_t *bp = vu_payloadv6(iov_vu[0].iov_base); + struct ipv6hdr *ip6h = vu_ip(iov[0].iov_base); + struct udp_payload_t *bp = vu_payloadv6(iov[0].iov_base);
eh->h_proto = htons(ETH_P_IPV6);
@@ -147,23 +145,25 @@ static size_t udp_vu_prepare(const struct ctx *c, /** * udp_vu_csum() - Calculate and set checksum for a UDP packet * @toside: Address information for one side of the flow - * @iov_used: Number of used iov_vu items + * @iov: IO vector for the frame + * @cnt: Number of IO vector entries */ -static void udp_vu_csum(const struct flowside *toside, int iov_used) +static void udp_vu_csum(const struct flowside *toside, const struct iovec *iov, + size_t cnt) { const struct in_addr *src4 = inany_v4(&toside->oaddr); const struct in_addr *dst4 = inany_v4(&toside->eaddr); - char *base = iov_vu[0].iov_base; + char *base = iov[0].iov_base; struct udp_payload_t *bp; struct iov_tail data;
if (src4 && dst4) { bp = vu_payloadv4(base); - data = IOV_TAIL(iov_vu, iov_used, (char *)&bp->data - base); + data = IOV_TAIL(iov, cnt, (char *)&bp->data - base); csum_udp4(&bp->uh, *src4, *dst4, &data); } else { bp = vu_payloadv6(base); - data = IOV_TAIL(iov_vu, iov_used, (char *)&bp->data - base); + data = IOV_TAIL(iov, cnt, (char *)&bp->data - base); csum_udp6(&bp->uh, &toside->oaddr.a6, &toside->eaddr.a6, &data); } } @@ -178,7 +178,9 @@ static void udp_vu_csum(const struct flowside *toside, int iov_used) void udp_vu_sock_to_tap(const struct ctx *c, int s, int n, flow_sidx_t tosidx) { const struct flowside *toside = flowside_at_sidx(tosidx); + static struct vu_virtq_element elem[VIRTQUEUE_MAX_SIZE]; bool v6 = !(inany_v4(&toside->eaddr) && inany_v4(&toside->oaddr)); + static struct iovec iov_vu[VIRTQUEUE_MAX_SIZE]; struct vu_dev *vdev = c->vdev; struct vu_virtq *vq = &vdev->vq[VHOST_USER_RX_QUEUE]; int i; @@ -211,9 +213,9 @@ void udp_vu_sock_to_tap(const struct ctx *c, int s, int n, flow_sidx_t tosidx)
assert((size_t)elem_cnt == iov_cnt); /* one iovec per element */
- dlen = udp_vu_sock_recv(s, v6, &iov_cnt); + dlen = udp_vu_sock_recv(iov_vu, &iov_cnt, s, v6); if (dlen < 0) { - vu_queue_rewind(vq, iov_cnt); + vu_queue_rewind(vq, elem_cnt); break; }
@@ -223,12 +225,12 @@ void udp_vu_sock_to_tap(const struct ctx *c, int s, int n, flow_sidx_t tosidx) vu_queue_rewind(vq, elem_cnt - elem_used);
if (iov_cnt > 0) { - udp_vu_prepare(c, toside, dlen); + udp_vu_prepare(c, iov_vu, toside, dlen); if (*c->pcap) { - udp_vu_csum(toside, iov_cnt); + udp_vu_csum(toside, iov_vu, iov_cnt); pcap_iov(iov_vu, iov_cnt, VNET_HLEN); } <> - vu_flush(vdev, vq, elem, iov_cnt); + vu_flush(vdev, vq, elem, elem_used); vu_queue_notify(vdev, vq); } } -- 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