[PATCH 19.11] net/virtio-user: fix socket non-blocking mode
Christian Ehrhardt
christian.ehrhardt at canonical.com
Wed Aug 3 11:50:57 CEST 2022
On Thu, Jul 14, 2022 at 11:22 AM Yuan Wang <yuanx.wang at intel.com> wrote:
>
> [ upstream commit 41f9a1757ffc010cc3debaad9a56af8ad88d0c6d ]
Thank you,
your patch was in time, but sadly a few fell through the cracks on my side.
(and many more just arrived too late).
Your patch is applied to the WIP branch now, but currently testing of
-rc1 is going on which I do not want to disrupt.
If we need an -rc2 anyway or generally have the time to do an -rc2
without too much disruption it will be in 19.11.13, otherwise it is
already queued for 19.11.14
> The virtio-user initialization requires unix socket to receive backend
> messages in block mode. However, virtio_user_read_dev_config() sets
> the same socket to nonblocking via fcntl, which affects all threads.
> Enabling the rxq interrupt can causes both of these behaviors to occur
> concurrently, with the result that the initialization may fail
> because no messages are received in nonblocking socket.
>
> Fix that by replacing O_NONBLOCK with the recv per-call option
> MSG_DONTWAIT.
>
> Fixes: ef53b6030039 ("net/virtio-user: support LSC")
>
> Signed-off-by: Yuan Wang <yuanx.wang at intel.com>
> Acked-by: Stephen Hemminger <stephen at networkplumber.org>
> Reviewed-by: Chenbo Xia <chenbo.xia at intel.com>
> ---
> drivers/net/virtio/virtio_user_ethdev.c | 15 ++-------------
> 1 file changed, 2 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
> index 2fccf9fce..1c07caeb5 100644
> --- a/drivers/net/virtio/virtio_user_ethdev.c
> +++ b/drivers/net/virtio/virtio_user_ethdev.c
> @@ -211,15 +211,9 @@ virtio_user_read_dev_config(struct virtio_hw *hw, size_t offset,
>
> if (dev->vhostfd >= 0) {
> int r;
> - int flags;
>
> - flags = fcntl(dev->vhostfd, F_GETFL);
> - if (fcntl(dev->vhostfd, F_SETFL,
> - flags | O_NONBLOCK) == -1) {
> - PMD_DRV_LOG(ERR, "error setting O_NONBLOCK flag");
> - return;
> - }
> - r = recv(dev->vhostfd, buf, 128, MSG_PEEK);
> + r = recv(dev->vhostfd, buf, 128,
> + MSG_PEEK | MSG_DONTWAIT);
> if (r == 0 || (r < 0 && errno != EAGAIN)) {
> dev->net_status &= (~VIRTIO_NET_S_LINK_UP);
> PMD_DRV_LOG(ERR, "virtio-user port %u is down",
> @@ -235,11 +229,6 @@ virtio_user_read_dev_config(struct virtio_hw *hw, size_t offset,
> } else {
> dev->net_status |= VIRTIO_NET_S_LINK_UP;
> }
> - if (fcntl(dev->vhostfd, F_SETFL,
> - flags & ~O_NONBLOCK) == -1) {
> - PMD_DRV_LOG(ERR, "error clearing O_NONBLOCK flag");
> - return;
> - }
> } else if (dev->is_server) {
> dev->net_status &= (~VIRTIO_NET_S_LINK_UP);
> if (virtio_user_server_reconnect(dev) >= 0)
> --
> 2.25.1
>
--
Christian Ehrhardt
Senior Staff Engineer, Ubuntu Server
Canonical Ltd
More information about the stable
mailing list