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KVM: x86: expose invariant tsc cpuid bit

PATCH Marcelo Tosatti 2 participants 3 messages Apr 25, 2014 – Apr 29, 2014

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x86 KVM KVM x86
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Marcelo Tosatti

author
#0 lore raw

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

Signed-off-by Marcelo Tosatti <[email protected]>
arch/x86/kvm/cpuid.c +5 -1
index f47a104..4f076d7 100644
@@ -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:
author
#1 lore raw

KVM: x86: expose invariant tsc cpuid bit (v2)

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

Signed-off-by Marcelo Tosatti <[email protected]>
arch/x86/kvm/cpuid.c +7 -1
index f47a104..333b88d 100644
@@ -495,6 +495,13 @@ 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);
+		/* mask against host */
+		entry->edx &= boot_cpu_data.x86_power;
+		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 +532,6 @@ 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:
maintainer
#2 lore raw

Re: KVM: x86: expose invariant tsc cpuid bit (v2)

Il 27/04/2014 03:30, Marcelo Tosatti ha scritto:

Quoted 26 lines

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

Signed-off-by Marcelo Tosatti <[email protected]>
arch/x86/kvm/cpuid.c +7 -0
index f47a104..333b88d 100644
@@ -495,6 +495,13 @@ 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);
+		/* mask against host */
+		entry->edx &= boot_cpu_data.x86_power;
+		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);

arch/x86/kvm/cpuid.c static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, · line 537

Quoted 7 lines
arch/x86/kvm/cpuid.c +0 -1
@@ -525,7 +532,6 @@ 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:

Applying to kvm/queue, thanks.

Paolo