From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH] xen/arm: Make local_events_need_delivery working with idle VPCU Date: Tue, 5 May 2015 15:37:29 +0100 Message-ID: <5548D5A9.6060101@citrix.com> References: <1430145540-31032-1-git-send-email-julien.grall@citrix.com> <553E6489.30300@citrix.com> <1430826035.2660.52.camel@citrix.com> <5548B0FB.1000900@citrix.com> <1430828998.2660.70.camel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1Ype3b-0005SD-BO for xen-devel@lists.xenproject.org; Tue, 05 May 2015 14:42:47 +0000 In-Reply-To: <1430828998.2660.70.camel@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: Ian Campbell , Julien Grall Cc: Stefano Stabellini , Andrew Cooper , Riku Voipio , Tim Deegan , stefano.stabellini@citrix.com, Jan Beulich , xen-devel@lists.xenproject.org, Tamas K Lengyel List-Id: xen-devel@lists.xenproject.org On 05/05/15 13:29, Ian Campbell wrote: > On Tue, 2015-05-05 at 13:00 +0100, Julien Grall wrote: >>> I'm inclined to just go with this patch for now, unless Stefano is >>> nacking it. >> >> This patch seem to turn into a workaround, would it be better to move >> check idle_check in apply_p2m_check? >> >> I will prepare a follow-up to avoid properly the call >> hypercall_preempt_check with idle_vcpu. >> >>> One question first: What aspect of local_events_need_delivery relies on >>> the vcpu not being an idle one? I suppose something is not initialised, >>> but what. >> >> Everything related to the vGIC is not initialized. It's used in >> local_event_need_delivery_nomask (see irq_to_pending and >> gic_events_need_devlivery). > > Would it be better to arrange that vcpu_event_delivery_is_enabled is > never true for an idle vcpu? Either with an explicit check or by > arranging regs->cpsr to say that? That could work. Although, as discussed IRL, I will move the check of idle_vcpu in apply_p2m_changes in a preempt variable. Regards, -- Julien Grall