From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [patch 1/2] KVM: hlt emulation should take in-kernel APIC/PIT timers into account Date: Mon, 12 May 2008 13:40:05 -0300 Message-ID: <20080512164005.GA25436@dmt> References: <20080410201254.316224847@localhost.localdomain> <200805091549.20620.sheng.yang@intel.com> <20080509145300.GA11955@dmt> <200805101012.03113.sheng.yang@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel@lists.sourceforge.net, Avi Kivity To: "Yang, Sheng" Return-path: Content-Disposition: inline In-Reply-To: <200805101012.03113.sheng.yang@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces@lists.sourceforge.net Errors-To: kvm-devel-bounces@lists.sourceforge.net List-Id: kvm.vger.kernel.org On Sat, May 10, 2008 at 10:12:02AM +0800, Yang, Sheng wrote: > > Did you have kvm.git commit 8ae6dc90ac84d9734e343210c8ec709f50cd9d89 > > when testing this? > > > > I believe it should fix that issue, because "ps->inject_pending" won't > > be set by kvm_pit_timer_intr_post() if the IRQ is masked. Please correct > > me if I'm wrong. > > Oh, sorry, I missed that commit. But... It just solved an half of the problem. > LAPIC suffered from it as well, and the current HLT emulation still didn't > work... And I can't find something like inject_pending in LAPIC timer. > > I have to say, I think my method is more preciously, directly and efficient... > It also can be extended easily if we got more clock sources (though I don't > think this would happen in near future...). In fact, I think take care of > pending counts is some kind of *wrong concept*... We should take care of the > window, or when the increment of pending counters happened, CMIIW. And it got > nothing to do with the current counter number (yeah, I realized it after saw > the hlt behaviour in XP, not before ;) ). Sheng, The problem is that you don't want to emulate hlt if you have a pending timer _and_ the guest is accepting events. So for example if there are two apic timers pending, you inject one of them, guest execute's hlt, we end up in vcpu_block(). Does this work for you? diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 7652f88..d41e34c 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -961,7 +961,7 @@ int apic_has_pending_timer(struct kvm_vcpu *vcpu) { struct kvm_lapic *lapic = vcpu->arch.apic; - if (lapic) + if (lapic && apic_enabled(lapic) && apic_lvt_enabled(lapic, APIC_LVTT)) return atomic_read(&lapic->timer.pending); return 0; ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone