From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Dunlap Subject: Re: [PATCH v7 15/17] vmx: VT-d posted-interrupt core logic handling Date: Thu, 17 Sep 2015 12:44:44 +0100 Message-ID: <55FAA7AC.3010909@citrix.com> References: <1441960146-10569-1-git-send-email-feng.wu@intel.com> <1441960146-10569-16-git-send-email-feng.wu@intel.com> <1442423887.15327.29.camel@citrix.com> <1442479704.15327.65.camel@citrix.com> <55FA8A02.30705@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <55FA8A02.30705@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Dario Faggioli , "Wu, Feng" Cc: "Tian, Kevin" , Keir Fraser , George Dunlap , Andrew Cooper , "xen-devel@lists.xen.org" , Jan Beulich List-Id: xen-devel@lists.xenproject.org On 09/17/2015 10:38 AM, George Dunlap wrote: > Is it the case that the interrupt is not actually delivered to the > processor, but that the pending bit will be set in the pi field, so that > the interrupt will be delivered the next time the hypervisor returns > into the guest? > > (I am assuming that is the case, because if the hypervisor *does* get an > interrupt, then it can just unblock it there.) Actually, it looks like you *do* in fact get a pi_notification_interrupt() in this case. Could we to check to see if the current vcpu is blocked and unblock it? I haven't yet decided whether I prefer my original suggestion of switching the interrupt and putting things on the wake-up list in vcpu_block(), or of deferring adding things to the wake-up list until the actual context switch. -George