On 1 August 2016 at 14:26, Andrea Bolognani <abolo...@redhat.com> wrote: > On Mon, 2016-08-01 at 15:08 +0200, Andrew Jones wrote: >> > I'm not sure a warning is enough: if I start a guest and >> > explicitly ask for a PMU, I expect it to be there, or for >> > the guest not to start at all. How does x86 behave in this >> > regard? >> >> Peter had a good suggestion for this. We need to wrap the property >> addition in an arm_feature check like the has_el3 property. That will >> remove it from all cpu types that don't support it. > > Wouldn't that mean that you'd be unable to use > > -cpu foo,pmu=off > > if CPU model 'foo' doesn't support a PMU? I'd expect that > to work.
The current precedent (has_el3) doesn't work like that: if foo isn't a CPU which can support EL3 then the property doesn't exist, and it's an error to try to set it. thanks -- PMM
