Re: [Qemu-devel] [PATCH V3 WIP 3/3] disable vhost_verify_ring_mappings check

[Nicholas A. Bellinger]

On Thu, 2013-03-28 at 06:13 -0400, Paolo Bonzini wrote:
> > I think it's the right thing to do, but maybe not the right place
> > to do this, need to reset after all IO is done, before
> > ring memory is write protected.
> 
> Our emails are crossing each other unfortunately, but I want to
> reinforce this: ring memory is not write protected.

Understood.  However, AFAICT the act of write protecting these ranges
for ROM generates the offending callbacks to vhost_set_memory().

The part that I'm missing is if ring memory is not being write protected
by make_bios_readonly_intel(), why are the vhost_set_memory() calls
being invoked..?

> Remember that
> SeaBIOS can even provide virtio-scsi access to DOS, so you must
> not reset the device.  It must remain functional all the time,
> and the OS's own driver will reset it when it's started.
> 

Mmmm, so a vp_reset() is out of the question then..

--nab