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* KVM: x86: expose invariant tsc cpuid bit
@ 2014-04-25 22:15 Marcelo Tosatti
  2014-04-27  1:30 ` KVM: x86: expose invariant tsc cpuid bit (v2) Marcelo Tosatti
  0 siblings, 1 reply; 3+ messages in thread
From: Marcelo Tosatti @ 2014-04-25 22:15 UTC (permalink / raw)
  To: kvm-devel; +Cc: Paolo Bonzini


Invariant TSC is a property of TSC, no additional 
support code necessary.

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

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index f47a104..4f076d7 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -495,6 +495,11 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 		entry->ecx &= kvm_supported_word6_x86_features;
 		cpuid_mask(&entry->ecx, 6);
 		break;
+	case 0x80000007: /* Advanced power management */
+		/* invariant TSC is CPUID.80000007H:EDX[8] */
+		entry->edx &= (1 << 8);
+		entry->eax = entry->ebx = entry->ecx = 0;
+		break;
 	case 0x80000008: {
 		unsigned g_phys_as = (entry->eax >> 16) & 0xff;
 		unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
@@ -525,7 +530,6 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 	case 3: /* Processor serial number */
 	case 5: /* MONITOR/MWAIT */
 	case 6: /* Thermal management */
-	case 0x80000007: /* Advanced power management */
 	case 0xC0000002:
 	case 0xC0000003:
 	case 0xC0000004:

^ permalink raw reply related	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2014-04-29 13:13 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-04-25 22:15 KVM: x86: expose invariant tsc cpuid bit Marcelo Tosatti
2014-04-27  1:30 ` KVM: x86: expose invariant tsc cpuid bit (v2) Marcelo Tosatti
2014-04-29 13:12   ` Paolo Bonzini

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