Re: [Qemu-devel] [PATCH] qemu-char: another io_add_watch_poll fix

[Paolo Bonzini]

Il 12/04/2013 11:24, Amit Shah ha scritto:
> Can you try multiple writes from the guest?  At least 3-4?  QEMU
> doesn't detect a backend getting closed right away (another bug), so
> the freeze doesn't trigger til qemu detects there's no chardev
> anymore.

All writes after the second will hang and ^C will return

bash: echo: write error: Interrupted system call

Same for "yes > /dev/vport0p1".  The writes hang as soon as I exit nc on
the host, and ^C exits cleanly to the shell.

I think this patch is obvious.  You might be seeing another bug that
should be fixed separately.

Paolo

>>> There's a slight difference in my old qemu tree, I have Hans's
>>> "virtio-console: Remove any pending watches on close" patch applied,
>>> which makes use of the tag obtained on adding the watch.  That patch
>>> hasn't found its way to master yet, but it should go in soon.
>>
>> I don't have that patch in my (new) tree.  It's vanilla upstream QEMU.
> 
> Yep, I tested upstream QEMU from master as well.  (It's just my 'old'
> qemu tree which has Hans's patches too.)
> 
>               Amit
> 
>