From bad78b4b8b23412f6007efd034de04b35c663a6f Mon Sep 17 00:00:00 2001 From: Tiwei Bie Date: Tue, 12 Mar 2019 15:13:07 +0800 Subject: [PATCH] net/virtio-user: fix multiqueue with vhost kernel The multiqueue support in virtio-user with vhost kernel backend is broken when tap name isn't specified by users explicitly, because the tap name returned by ioctl(TUNSETIFF) isn't saved properly, and multiple tap interfaces will be created in this case. Fix this by saving the dynamically allocated tap name first before reusing the ifr structure. Besides, also make it possible to support the format string in tap name (e.g. foo%d) specified by users explicitly. Fixes: 791b43e08842 ("net/virtio-user: specify MAC of the tap") Cc: stable@dpdk.org Reported-by: Stephen Hemminger Signed-off-by: Tiwei Bie Reviewed-by: Maxime Coquelin Reviewed-by: Stephen Hemminger --- drivers/net/virtio/virtio_user/vhost_kernel_tap.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/net/virtio/virtio_user/vhost_kernel_tap.c b/drivers/net/virtio/virtio_user/vhost_kernel_tap.c index a3faf1d0c4..fbd9e979d7 100644 --- a/drivers/net/virtio/virtio_user/vhost_kernel_tap.c +++ b/drivers/net/virtio/virtio_user/vhost_kernel_tap.c @@ -62,6 +62,7 @@ vhost_kernel_open_tap(char **p_ifname, int hdr_size, int req_mq, const char *mac, uint64_t features) { unsigned int tap_features; + char *tap_name = NULL; int sndbuf = INT_MAX; struct ifreq ifr; int tapfd; @@ -112,6 +113,12 @@ vhost_kernel_open_tap(char **p_ifname, int hdr_size, int req_mq, goto error; } + tap_name = strdup(ifr.ifr_name); + if (!tap_name) { + PMD_DRV_LOG(ERR, "strdup ifname failed: %s", strerror(errno)); + goto error; + } + fcntl(tapfd, F_SETFL, O_NONBLOCK); if (ioctl(tapfd, TUNSETVNETHDRSZ, &hdr_size) < 0) { @@ -134,11 +141,12 @@ vhost_kernel_open_tap(char **p_ifname, int hdr_size, int req_mq, goto error; } - if (!(*p_ifname)) - *p_ifname = strdup(ifr.ifr_name); + free(*p_ifname); + *p_ifname = tap_name; return tapfd; error: + free(tap_name); close(tapfd); return -1; } -- 2.20.1