From: Stephen Hemminger <stephen@networkplumber.org>
To: Yuan Wang <yuanx.wang@intel.com>
Cc: maxime.coquelin@redhat.com, chenbo.xia@intel.com, dev@dpdk.org,
jiayu.hu@intel.com, xingguang.he@intel.com, stable@dpdk.org
Subject: Re: [PATCH] net/virtio: fix socket nonblocking mode affects initialization
Date: Thu, 16 Jun 2022 20:05:09 -0700 [thread overview]
Message-ID: <20220616200509.111a9686@hermes.local> (raw)
In-Reply-To: <20220617024229.706826-1-yuanx.wang@intel.com>
On Fri, 17 Jun 2022 10:42:29 +0800
Yuan Wang <yuanx.wang@intel.com> wrote:
> The virtio-user initialization requires unix socket to receive backend
> messages in block mode. However, vhost_user_update_link_state() 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.
>
> Thread 1:
> virtio_init_device()
> --> virtio_user_start_device()
> --> vhost_user_set_memory_table()
> --> vhost_user_check_reply_ack()
>
> Thread 2:
> virtio_interrupt_handler()
> --> vhost_user_update_link_state()
>
> Fix that by replacing O_NONBLOCK with the recv per-call option
> MSG_DONTWAIT.
>
> Fixes: ef53b6030039 ("net/virtio-user: support LSC")
> Cc: stable@dpdk.org
>
> Signed-off-by: Yuan Wang <yuanx.wang@intel.com>
Looks good and saves a few system calls.
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
next prev parent reply other threads:[~2022-06-17 3:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-17 2:42 Yuan Wang
2022-06-17 3:05 ` Stephen Hemminger [this message]
2022-07-01 10:11 ` Xia, Chenbo
2022-07-01 13:53 ` Maxime Coquelin
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