On Thu, Jan 31, 2013 at 11:43:48AM +0200, Gleb Natapov wrote: > On Wed, Jan 30, 2013 at 09:03:11PM -0200, Marcelo Tosatti wrote: > > Posted interrupt patch: > > 2) Must move IN_GUEST_MODE assignment after local_irq_disable, in > > vcpu_enter_guest function. Otherwise: > > > > cpu0 vcpu1<->cpu1 > > > > vcpu->mode = IN_GUEST_MODE > > > > if IN_GUEST_MODE == true > > send IPI > > local_irq_disable > > > > PIR not transferred to VIRR, misses interrupt. > > > cpu0 will set KVM_REQ_EVENT, so vmentry will be aborted after > local_irq_disable() by ->requests check. Yes, but you don't want KVM_REQ_EVENT+kick. It defeats the purpose of posted interrupts. You want if vcpu in guest mode send posted interrupt IPI else KVM_REQ_EVENT+kick > > 3) Must check outstanding PIR notification bit unconditionally on > > every VM-entry, because: > > > > 1. local_irq_disable > > 2. vcpu->mode = IN_GUEST_MODE > > 3. vmenter > > 4. vmexit > > 5. vcpu->mode = OUTSIDE_GUEST_MODE > > > > If PIR-IPI-interrupt is sent between an event which triggers VM-exit > > (for example, an external interrupt due to a device), and step 5 > > (assignment of vcpu->mode), the PIR->VIRR transfer before vmentry must > > be made. > Not sure I understand, but I think KVM_REQ_EVENT will cover that too. See above. > > > > 4) Today, an interrupt notification is cached on IRR until its delivered - further > > interrupt injection is not generating further interrupt notification > > bits. With PIR, behaviour changes: Its possible to have one bit in PIR and another > > on IRR APIC page (if timing is right). Is this harmless? Why? > > > > > > -- > Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
