If the SynIC timer message delivery fails due to SINT message slot being busy, there's no point to attempt starting the timer again until we're notified of the slot being released by the guest (via EOM or EOI).
Even worse, when a oneshot timer fails to deliver its message, its re-arming with an expiration time in the past leads to immediate retry of the delivery, without ever letting the guest vcpu to run and release the slot, which results in a livelock. To avoid that, only start the timer when there's no timer message pending delivery. When the guest releases the slot, the processing is resumed so the timer will be started then. Signed-off-by: Roman Kagan <rka...@virtuozzo.com> --- arch/x86/kvm/hyperv.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index c8efdce3e702..ab9501c2f32c 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -632,9 +632,10 @@ void kvm_hv_process_stimers(struct kvm_vcpu *vcpu) } if ((stimer->config & HV_STIMER_ENABLE) && - stimer->count) - stimer_start(stimer); - else + stimer->count) { + if (!stimer->msg_pending) + stimer_start(stimer); + } else stimer_cleanup(stimer); } } -- 2.13.3 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel