On 02/24/2017 04:31 PM, Paolo Bonzini wrote:
>
> On 24/02/2017 15:46, Marc-André Lureau wrote:
>>>> + if (ret < 0 && errno != EAGAIN) {
>>>> + if (tcp_chr_read_poll(chr) <= 0) {
>>>> + tcp_chr_disconnect(chr);
>>>> + return len;
>>>>
>>> This change breaks a number of assumption in vhost-user code. Until now, a
>>> vhost-user function assumed that dev->vhost_ops would remain as long as the
>>> function is running, so it may call vhost_ops callbacks several time, which
>>> may eventually fail to do io, but no crash would occur. The disconnection
>>> would be handled later with the HUP handler. Now, vhost_ops may be cleared
>>> during a write (chr_disconnect -> CHR_EVENT_CLOSED in
>>> net_vhost_user_event). This can be randomly reproduced with
>>> vhost-user-test -p /x86_64/vhost-user/flags-mismatch/subprocess
> Would it work to call tcp_chr_disconnect from an idle source (and
> destroy the source on the next connect)?
>
> Paolo
I think no, but will think more on Monday. Unfortunately
today is official holiday in Russia :(
Right now the code loops forever. May be we should notify the
guest that the problem really happens.
Den
