> > On 20/02/2017 10:19, Gonglei (Arei) wrote: > > Hi Paolo, > > > >> > >> > >> On 16/02/2017 02:31, Gonglei (Arei) wrote: > >>> And the below patch works for me, I can support max 255 vcpus for > WS2012 > >>> with hyper-v enlightenments. > >>> > >>> diff --git a/target/i386/kvm.c b/target/i386/kvm.c > >>> index 27fd050..efe3cbc 100644 > >>> --- a/target/i386/kvm.c > >>> +++ b/target/i386/kvm.c > >>> @@ -772,7 +772,7 @@ int kvm_arch_init_vcpu(CPUState *cs) > >>> > >>> c = &cpuid_data.entries[cpuid_i++]; > >>> c->function = HYPERV_CPUID_IMPLEMENT_LIMITS; > >>> - c->eax = 0x40; > >>> + c->eax = -1; > >>> c->ebx = 0x40; > >>> > >>> kvm_base = KVM_CPUID_SIGNATURE_NEXT; > >> > >> This needs to depend on the machine type, but apart from that I think > > > > I don't know why. Because the negative effects for this change don't exist > > on current QEMU IIUC, and we don't have compatible problems for live > migration. > > CPUID should never change with the same machine type and command line. > OK, then how do we add compat code for the CPUID change? It's not a visible property.
Thanks, -Gonglei > Paolo > > >> you should submit the patch for 2.9. > >> > > > > Thanks, > > -Gonglei > >
