diff options
| -rw-r--r-- | hw/i386/kvm/clock.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/hw/i386/kvm/clock.c b/hw/i386/kvm/clock.c index 1ac60d6cdd..58be2bda27 100644 --- a/hw/i386/kvm/clock.c +++ b/hw/i386/kvm/clock.c @@ -127,7 +127,21 @@ static void kvmclock_vm_state_change(void *opaque, int running, } cpu_synchronize_all_states(); + /* In theory, the cpu_synchronize_all_states() call above wouldn't + * affect the rest of the code, as the VCPU state inside CPUState + * is supposed to always match the VCPU state on the kernel side. + * + * In practice, calling cpu_synchronize_state() too soon will load the + * kernel-side APIC state into X86CPU.apic_state too early, APIC state + * won't be reloaded later because CPUState.vcpu_dirty==true, and + * outdated APIC state may be migrated to another host. + * + * The real fix would be to make sure outdated APIC state is read + * from the kernel again when necessary. While this is not fixed, we + * need the cpu_clean_all_dirty() call below. + */ cpu_clean_all_dirty(); + ret = kvm_vm_ioctl(kvm_state, KVM_GET_CLOCK, &data); if (ret < 0) { fprintf(stderr, "KVM_GET_CLOCK failed: %s\n", strerror(ret)); |