From: Marcelo Tosatti <mtosa...@redhat.com>
Invariant TSC documentation mentions that "invariant TSC will run at a
constant rate in all ACPI P-, C-. and T-states".
This is not the case if migration to a host with different TSC frequency
is allowed, or if savevm is performed. So block migration/savevm.
Also do not expose invariant tsc flag by default.
Cc: Juan Quintela <quint...@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosa...@redhat.com>
Reviewed-by: Eduardo Habkost <ehabk...@redhat.com>
Signed-off-by: Eduardo Habkost <ehabk...@redhat.com>
---
target-i386/cpu-qom.h | 2 +-
target-i386/kvm.c | 13 +++++++++++++
target-i386/machine.c | 2 +-
3 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/target-i386/cpu-qom.h b/target-i386/cpu-qom.h
index 016f90d..473d803 100644
--- a/target-i386/cpu-qom.h
+++ b/target-i386/cpu-qom.h
@@ -121,7 +121,7 @@ static inline X86CPU *x86_env_get_cpu(CPUX86State *env)
#define ENV_OFFSET offsetof(X86CPU, env)
#ifndef CONFIG_USER_ONLY
-extern const struct VMStateDescription vmstate_x86_cpu;
+extern struct VMStateDescription vmstate_x86_cpu;
#endif
/**
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 4389959..99cc7e3 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -33,6 +33,8 @@
#include "exec/ioport.h"
#include <asm/hyperv.h>
#include "hw/pci/pci.h"
+#include "migration/migration.h"
+#include "qapi/qmp/qerror.h"
//#define DEBUG_KVM
@@ -447,6 +449,8 @@ static bool hyperv_enabled(X86CPU *cpu)
cpu->hyperv_relaxed_timing);
}
+Error *invtsc_mig_blocker;
+
#define KVM_MAX_CPUID_ENTRIES 100
int kvm_arch_init_vcpu(CPUState *cs)
@@ -702,6 +706,15 @@ int kvm_arch_init_vcpu(CPUState *cs)
!!(c->ecx & CPUID_EXT_SMX);
}
+ c = cpuid_find_entry(&cpuid_data.cpuid, 0x80000007, 0);
+ if (c && (c->edx & 1<<8) && invtsc_mig_blocker == NULL) {
+ /* for migration */
+ error_set(&invtsc_mig_blocker, QERR_MIGRATION_NOT_SUPPORTED, "cpu");
+ migrate_add_blocker(invtsc_mig_blocker);
+ /* for savevm */
+ vmstate_x86_cpu.unmigratable = 1;
+ }
+
cpuid_data.cpuid.padding = 0;
r = kvm_vcpu_ioctl(cs, KVM_SET_CPUID2, &cpuid_data);
if (r) {
diff --git a/target-i386/machine.c b/target-i386/machine.c
index 168cab6..4d4c023 100644
--- a/target-i386/machine.c
+++ b/target-i386/machine.c
@@ -613,7 +613,7 @@ static const VMStateDescription vmstate_msr_hyperv_time = {
}
};
-const VMStateDescription vmstate_x86_cpu = {
+VMStateDescription vmstate_x86_cpu = {
.name = "cpu",
.version_id = 12,
.minimum_version_id = 3,
--
1.9.0
