Re: bug disabling guest interface

Wei Liu
Wed, 06 Mar 2013 18:17:20 -0000

On Tue, 2013-03-05 at 22:51 +0000, Jacek Milewicz wrote:
> Hi all
>
> We have recently encountered a bug in xen causing guest interface to be
> disabled in certain conditions:
> - dom0 with this patch https://patchwork.kernel.org/patch/2164311/
> - guest kernel built in way that makes guest MAX_SKB_FRAGS larger than
> MAX_SKB_FRAGS on dom0

I''m interested in knowing more information. Have you always been using
MAX_SKB_FRAGS > default_value (16 or 17) for you DomUs?

If it is this case, you''re likely to be hitting this error path all the
time. It is just that XSA-39 chooses to shutdown vif if there is
something wrong. So my further questions is, do you notice any
performance problem in the case that netback silently drops your
packets?


Wei.