[Lguest] Virtio block problems on newer kernels

[Sakari Ailus]

Hi,

Has anyone else noticed problems with virtio block devices on 3.13.6 (or 
such)? 3.10.10 still works. The guest kernel version seems to matter, 
3.13.6 on the host appears to be working fine whereas that same kernel 
on the guest did not.

Sometimes there's a lot of latency (minutes rather than seconds!); I've 
had a guest hung waiting for I/O for hours. No log messages on the guest 
console or on the host. There are no block device issues on the host and 
at the same time other guests run just fine.

I haven't had time to debug this further and bisecting will be painful 
as this isn't that easy to reproduce: I first noticed after running 
3.13.6 for a day but first thought it was a network issue. The problem 
appeared between the two above versions (3.10.10 and 3.13.6).

-- 
Kind regards,

Sakari Ailus
sakari.ailus at iki.fi