KVM: Mask KVM_GET_SUPPORTED_CPUID data with Linux cpuid info

This allows Linux to mask cpuid bits if, for example, nx is enabled on only
some cpus.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c673e72..651cf90 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2227,6 +2227,11 @@ out:
        return r;
 }
 
+static void cpuid_mask(u32 *word, int wordnum)
+{
+       *word &= boot_cpu_data.x86_capability[wordnum];
+}
+
 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
                           u32 index)
 {
@@ -2301,7 +2306,9 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
                break;
        case 1:
                entry->edx &= kvm_supported_word0_x86_features;
+               cpuid_mask(&entry->edx, 0);
                entry->ecx &= kvm_supported_word4_x86_features;
+               cpuid_mask(&entry->ecx, 4);
                /* we support x2apic emulation even if host does not support
                 * it since we emulate x2apic in software */
                entry->ecx |= F(X2APIC);
@@ -2392,7 +2399,9 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
                break;
        case 0x80000001:
                entry->edx &= kvm_supported_word1_x86_features;
+               cpuid_mask(&entry->edx, 1);
                entry->ecx &= kvm_supported_word6_x86_features;
+               cpuid_mask(&entry->ecx, 6);
                break;
        }