Hypervisor Function Specification(HFS) doesn't require to disable SynIC timer at timer config write if timer->count = 0.
So drop this check, this allow to load timers MSR's during migration restore, because config are set before count in QEMU side. Also fix condition according to HFS doc(15.3.1): "It is not permitted to set the SINTx field to zero for an enabled timer. If attempted, the timer will be marked disabled (that is, bit 0 cleared) immediately." Signed-off-by: Andrey Smetanin <asmeta...@virtuozzo.com> Reviewed-by: Roman Kagan <rka...@virtuozzo.com> CC: Gleb Natapov <g...@kernel.org> CC: Paolo Bonzini <pbonz...@redhat.com> CC: Roman Kagan <rka...@virtuozzo.com> CC: Denis V. Lunev <d...@openvz.org> CC: qemu-devel@nongnu.org --- arch/x86/kvm/hyperv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index ce17529..b203ce3 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -472,7 +472,7 @@ static int stimer_start(struct kvm_vcpu_hv_stimer *stimer) static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config, bool host) { - if (stimer->count == 0 || HV_STIMER_SINT(config) == 0) + if ((stimer->config & HV_STIMER_ENABLE) && HV_STIMER_SINT(config) == 0) config &= ~HV_STIMER_ENABLE; stimer->config = config; stimer_cleanup(stimer); -- 2.4.3