On Fri, Oct 23, 2020 at 2:07 AM Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote: > > On 22/10/20 19:13, Jim Mattson wrote: > > We don't actually use KVM_GET_SUPPORTED_CPUID at all today. If it's > > commonly being misinterpreted as you say, perhaps we should add a > > KVM_GET_TRUE_SUPPORTED_CPUID ioctl. Or, perhaps we can just fix this > > in the documentation? > > Yes, I think we should fix the documentation and document the best > practices around MSRs and CPUID bits. Mostly documenting what QEMU > does, perhaps without all the quirks it has to support old kernels that > messed things up even more. > > Paolo I'd really like to be able to call an ioctl that will help me determine whether the host can support the guest CPUID information that I already have (e.g. on the target of a live migration). At first glance, KVM_GET_SUPPORTED_CPUID appeared to be that ioctl. Sadly, it appears that no such ioctl exists.
