KVM: Sanitize cpuid

Instead of blacklisting known-unsupported cpuid leaves, whitelist known-
supported leaves.  This is more conservative and prevents us from reporting
features we don't support.  Also whitelist a few more leaves while at it.

Signed-off-by: Avi Kivity <avi@redhat.com>
Acked-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0b08986..da48622 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2283,6 +2283,13 @@ static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
        entry->flags = 0;
 }
 
+static bool supported_xcr0_bit(unsigned bit)
+{
+       u64 mask = ((u64)1 << bit);
+
+       return mask & (XSTATE_FP | XSTATE_SSE | XSTATE_YMM) & host_xcr0;
+}
+
 #define F(x) bit(X86_FEATURE_##x)
 
 static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
@@ -2393,6 +2400,8 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
                }
                break;
        }
+       case 9:
+               break;
        case 0xb: {
                int i, level_type;
 
@@ -2414,7 +2423,7 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 
                entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
                for (i = 1; *nent < maxnent && i < 64; ++i) {
-                       if (entry[i].eax == 0)
+                       if (entry[i].eax == 0 || !supported_xcr0_bit(i))
                                continue;
                        do_cpuid_1_ent(&entry[i], function, i);
                        entry[i].flags |=
@@ -2451,6 +2460,24 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
                entry->ecx &= kvm_supported_word6_x86_features;
                cpuid_mask(&entry->ecx, 6);
                break;
+       case 0x80000008: {
+               unsigned g_phys_as = (entry->eax >> 16) & 0xff;
+               unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
+               unsigned phys_as = entry->eax & 0xff;
+
+               if (!g_phys_as)
+                       g_phys_as = phys_as;
+               entry->eax = g_phys_as | (virt_as << 8);
+               entry->ebx = entry->edx = 0;
+               break;
+       }
+       case 0x80000019:
+               entry->ecx = entry->edx = 0;
+               break;
+       case 0x8000001a:
+               break;
+       case 0x8000001d:
+               break;
        /*Add support for Centaur's CPUID instruction*/
        case 0xC0000000:
                /*Just support up to 0xC0000004 now*/
@@ -2460,10 +2487,16 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
                entry->edx &= kvm_supported_word5_x86_features;
                cpuid_mask(&entry->edx, 5);
                break;
+       case 3: /* Processor serial number */
+       case 5: /* MONITOR/MWAIT */
+       case 6: /* Thermal management */
+       case 0xA: /* Architectural Performance Monitoring */
+       case 0x80000007: /* Advanced power management */
        case 0xC0000002:
        case 0xC0000003:
        case 0xC0000004:
-               /*Now nothing to do, reserved for the future*/
+       default:
+               entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
                break;
        }