| Message ID | 1242378078-1908-2-git-send-email-agraf@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Alexander Graf wrote: > When using nested SVM we usually want the guest to see the exact CPUID values > we gave it and not some mangled ones. > That would triggered by -cpu host, not nesting. > @@ -1506,7 +1506,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, > *edx = env->cpuid_features; > > /* "Hypervisor present" bit required for Microsoft SVVP */ > - if (kvm_enabled()) > + if (kvm_enabled() && !kvm_nested) > *ecx |= (1 << 31); > break; > -cpu host,-hypervisor
On 15.05.2009, at 13:09, Avi Kivity wrote: > Alexander Graf wrote: >> When using nested SVM we usually want the guest to see the exact >> CPUID values >> we gave it and not some mangled ones. >> > > That would triggered by -cpu host, not nesting. Oh we have -cpu host already? If so, we don't need that hackery of course :-) >> @@ -1506,7 +1506,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t >> index, uint32_t count, >> *edx = env->cpuid_features; >> /* "Hypervisor present" bit required for Microsoft SVVP */ >> - if (kvm_enabled()) >> + if (kvm_enabled() && !kvm_nested) >> *ecx |= (1 << 31); >> break; >> > > -cpu host,-hypervisor hm - treating the hypervisor bit like any other cpuid bit sounds like a good idea. I'm wondering though which way should be preferred. I usually don't want to have the hypervisor bit set - but maybe I'm the minority. Alex -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Alexander Graf wrote: >>> When using nested SVM we usually want the guest to see the exact >>> CPUID values >>> we gave it and not some mangled ones. >>> >> >> That would triggered by -cpu host, not nesting. > > Oh we have -cpu host already? No, we don't :) > hm - treating the hypervisor bit like any other cpuid bit sounds like > a good idea. I'm wondering though which way should be preferred. I > usually don't want to have the hypervisor bit set - but maybe I'm the > minority. > Windows requires the hypervisor bit to set in order to pass some testing program.
diff --git a/target-i386/helper.c b/target-i386/helper.c index 24fcea8..5f56698 100644 --- a/target-i386/helper.c +++ b/target-i386/helper.c @@ -1496,7 +1496,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, * isn't supported in compatibility mode on Intel. so advertise the * actuall cpu, and say goodbye to migration between different vendors * is you use compatibility mode. */ - if (kvm_enabled()) + if (kvm_enabled() && !kvm_nested) host_cpuid(0, 0, NULL, ebx, ecx, edx); break; case 1: @@ -1506,7 +1506,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, *edx = env->cpuid_features; /* "Hypervisor present" bit required for Microsoft SVVP */ - if (kvm_enabled()) + if (kvm_enabled() && !kvm_nested) *ecx |= (1 << 31); break; case 2:
When using nested SVM we usually want the guest to see the exact CPUID values we gave it and not some mangled ones. Hyper-V for example doesn't even start when the "hypervisor present" bit is set. Signed-off-by: Alexander Graf <agraf@suse.de> --- target-i386/helper.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-)