Re: [Qemu-devel] [PATCH] virtio: Introduce virtio-testdev

[Gleb Natapov]

On Tue, Oct 15, 2013 at 11:14:12AM +0100, Peter Maydell wrote:
> On 15 October 2013 10:47, Anup Patel <address@hidden> wrote:
> > On Tue, Oct 15, 2013 at 2:06 PM, Andrew Jones <address@hidden> wrote:
> >> I'm not opposed to it, but at the moment I'm not sure how we would
> >> utilize it within kvm-unit-tests. Maybe it would be useful for another
> >> application though? So maybe we can add it as an add-on patch at the
> >> time we come up with its use case?
> >
> > I suggested it because we have "machvirt" machine in QEMU for
> > KVM ARM/ARM64 which has only VirtIO devices. In "machvirt", we
> > don't have mechanism to reset the system because none of the
> > VirtIO devices have such a mechanism. Now since you are introducing
> > a "testdev", we can have a RESET command in VirtIO and implement
> > VirtIO REBOOT driver in Linux kernel to use it.
> >
> > Currently, due to no RESET support in "machvirt" we are not able
> > to reboot Guest Linux from Guest console.
> 
> We shouldn't be abusing a device intended for testing to
> provide necessary features. If we need guest reboot support
> (which seems like an obvious thing to want) then we need
> to implement a sensible mechanism for it.
> 
Definitely. Test device is only for use by unit tests. It does not normally
present and may contain hacks not suitable for human consumption.

--
                        Gleb.