Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756483Ab0BXK2L (ORCPT ); Wed, 24 Feb 2010 05:28:11 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58423 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756293Ab0BXK2H (ORCPT ); Wed, 24 Feb 2010 05:28:07 -0500 Message-ID: <4B84FF2F.5040705@redhat.com> Date: Wed, 24 Feb 2010 12:27:59 +0200 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.7) Gecko/20100120 Fedora/3.0.1-1.fc12 Thunderbird/3.0.1 MIME-Version: 1.0 To: Jan Kiszka CC: Thomas Gleixner , KVM , Gleb Natapov , RT , Linux Kernel Mailing List Subject: Re: [PATCH] KVM: x86: Kick VCPU outside PIC lock again References: <20100217135901.331576359@linutronix.de> <4B842A1F.50601@siemens.com> <4B84F466.2080009@siemens.com> <4B84F5D4.5020202@redhat.com> <4B84F765.5040209@siemens.com> <4B84F9AF.8060804@redhat.com> <4B84FBDB.1070006@siemens.com> <4B84FCBB.8070702@redhat.com> <4B84FDF5.5080106@siemens.com> In-Reply-To: <4B84FDF5.5080106@siemens.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1199 Lines: 40 On 02/24/2010 12:22 PM, Jan Kiszka wrote: > Avi Kivity wrote: > >> On 02/24/2010 12:13 PM, Jan Kiszka wrote: >> >>> >>> >>>> I see. Won't we hit the same issue when we call pic functions from >>>> atomic context during the guest entry sequence? >>>> >>>> >>>> >>> If there are such call paths, for sure. What concrete path(s) do you >>> have in mind? >>> >>> >>> >> vcpu_enter_guest() -> inject_pending_event() -> >> kvm_cpu_{has,get}_interrupt() -> various pic functions if you're unlucky. >> > But do they kick anyone or just check/pull information? Probably not, kicking should be a side effect (or rather the main effect) of queueing an interrupt, not dequeuing it. > Never saw any > warnings during my tests last year (granted: with older -rt and kvm > versions). > Well, most guests kill the pic early on. Will apply the patch. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/