Re: [Qemu-devel] [PATCH RFC V2 4/4] Add virtv2 machine that uses GIC-500

[Pavel Fedin <p.fedin@samsung.com>]

 Hello!

> I accept that virtv2 is not needed and I'm currently using Pavel's patch
> https://lists.gnu.org/archive/html/qemu-devel/2015-05/msg02930.html with small
> modifications.
> However If there is a consensus I'll move to Ashok's virt instead of Pavel's one.
> 
> I'm looking forward for a decision regarding which virt is to be used.

 I have just tried Ashok's approach and unfortunately it does not work well. The problem
is mc->max_cpus. Ashok's patch does not do anything with it because he seemed to be
satisfied with the maximum of 8. And it looks like CPU number limitation is evaluated
before machine is instantiated and properties are evaluated. I tried to change this value
inside virt_set_gic_version() (see Ashok's code), but it simply does not work, and i still
get " Maximum CPUs greater than specified machine type limit" from qemu.
 I believe there can be some fix, but it seems to require much more changes than simply
subclassing a machine. Does it worth that? And, by the way, libvirt has now added
recognition of "virt-" prefix too.

Kind regards,
Pavel Fedin
Expert Engineer
Samsung Electronics Research center Russia