commit 6389c45441269baa2873e6feafebd17105ddeaf6 Author: Jan Kiszka <jan.kis...@siemens.com> Date: Mon Mar 1 18:17:26 2010 +0100
qemu-kvm: Cleanup/fix TSC and PV clock writeback Signed-off-by: Marcelo Tosatti <mtosa...@redhat.com> --- target-i386/kvm.c | 10 +++++++++- 1 files changed, 9 insertions(+), 1 deletions(-) diff --git a/target-i386/kvm.c b/target-i386/kvm.c index 06474d6..e2f7e2e 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -817,7 +817,15 @@ static int kvm_put_msrs(CPUState *env, int level) kvm_msr_entry_set(&msrs[n++], MSR_LSTAR, env->lstar); #endif if (level == KVM_PUT_FULL_STATE) { - kvm_msr_entry_set(&msrs[n++], MSR_IA32_TSC, env->tsc); + /* + * KVM is yet unable to synchronize TSC values of multiple VCPUs on + * writeback. Until this is fixed, we only write the offset to SMP + * guests after migration, desynchronizing the VCPUs, but avoiding + * huge jump-backs that would occur without any writeback at all. + */ + if (smp_cpus == 1 || env->tsc != 0) { + kvm_msr_entry_set(&msrs[n++], MSR_IA32_TSC, env->tsc); + } kvm_msr_entry_set(&msrs[n++], MSR_KVM_SYSTEM_TIME, env->system_time_msr); kvm_msr_entry_set(&msrs[n++], MSR_KVM_WALL_CLOCK, env->wall_clock_msr); -- 1.7.2.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html