Re: [PATCH 1/6] accel: Introduce 'query-accels' QMP command
On 12/03/21 10:17, Andrew Jones wrote:
On Fri, Mar 12, 2021 at 10:01:43AM +0100, Paolo Bonzini wrote:
> On 12/03/21 09:48, Andrew Jones wrote:
>>> I think we definitely need the additional data section here: For KVM on
>>> POWER, it would be good to know whether it's KVM-HV or KVM-PR, for KVM
on
>>> MIPS it would be good to know whether it's KVM_VM_MIPS_VZ or
KVM_VM_MIPS_TE,
>>> for KVM on x86 whether it's the AMD flavor or Intel, ...
>>
>> Could also pre-expand all of these and list them individually.
>
> That seems worse (in general) because in a lot of cases you don't care; the
> basic query-accels output should match the argument to "-accel".
>
For these special subtypes, what's the property/state that indicates it
when just using '-accel kvm' on the command line? Because if this qmp
list matches the '-accel' parameter list, then qtest and other qmp clients
may need to query that other information too, in order for this accel
query to be useful. And, do we need an accel-specific qmp query for it?
Or, is that information already available?
It depends.
On PPC (if I remember/understand correctly) only pseries supports both
HV and PR, while all other machines only support KVM-PR. So in that
case it's a kvm-type machine property that is defined only for the
pseries machine.
On MIPS instead there's no option and VZ always wins over TE. I think
it could be made an option on -accel, but I'm not familiar with MIPS
machine types.
Something like "name: 'kvm', types: ['book3s-hv', 'pr']"
would work
nicely for KVM-PPC, and likewise for MIPS.
Paolo