KVM: nVMX: Add VMX to list of supported cpuid features

If the "nested" module option is enabled, add the "VMX" CPU feature to the
list of CPU features KVM advertises with the KVM_GET_SUPPORTED_CPUID ioctl.

Qemu uses this ioctl, and intersects KVM's list with its own list of desired
cpu features (depending on the -cpu option given to qemu) to determine the
final list of features presented to the guest.

Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index afc1f06907ce340cb0c5cc570941cda140d8bc67..a600fd7795f15c7ca862e74dc7fbbceb8d38b46e 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6299,6 +6299,8 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
 
 static void vmx_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry)
 {
+       if (func == 1 && nested)
+               entry->ecx |= bit(X86_FEATURE_VMX);
 }
 
 /*