From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754025AbbGGHLJ (ORCPT ); Tue, 7 Jul 2015 03:11:09 -0400 Received: from mail-wg0-f52.google.com ([74.125.82.52]:33944 "EHLO mail-wg0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752054AbbGGHK6 (ORCPT ); Tue, 7 Jul 2015 03:10:58 -0400 Message-ID: <559B7B6C.3060900@linaro.org> Date: Tue, 07 Jul 2015 09:10:36 +0200 From: Eric Auger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Paolo Bonzini , eric.auger@st.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, christoffer.dall@linaro.org, marc.zyngier@arm.com, alex.williamson@redhat.com, avi.kivity@gmail.com, mtosatti@redhat.com, feng.wu@intel.com, joro@8bytes.org, b.reynal@virtualopensystems.com CC: linux-kernel@vger.kernel.org, patches@linaro.org Subject: Re: [RFC v2 3/6] irq: bypass: Extend skeleton for ARM forwarding control References: <1436184692-20927-1-git-send-email-eric.auger@linaro.org> <1436184692-20927-4-git-send-email-eric.auger@linaro.org> <559A7425.4050506@redhat.com> <559AA02A.6060703@linaro.org> <559AA552.3010400@redhat.com> <559AB62C.9000503@linaro.org> <559ABDC5.3060200@redhat.com> In-Reply-To: <559ABDC5.3060200@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/06/2015 07:41 PM, Paolo Bonzini wrote: > > > On 06/07/2015 19:09, Eric Auger wrote: >>>> The good thing is that this helps a bit forming a lock hierarchy across >>>> the subsystems, for example irq bypass mutex outside vfio_platform_irq >>>> spinlock, because you cannot have a spinlock inside the mutex. I think >>>> that all of your six callbacks are fine. >> arghh, no that's wrong then. I have plenty of them in the KVM/arm vgic >> part :-( > > I checked and it's right... > > /me rereads > > AAAARGH. You cannot have a mutex inside a spinlock. What you're doing > is fine. Sweated up (+ heat wave in France). Was about to read again the "concurrency and race conditions" chapter of the linux driver bible. Might be worth anyway ;-) Many thanks for the review Eric > > Paolo > From mboxrd@z Thu Jan 1 00:00:00 1970 From: eric.auger@linaro.org (Eric Auger) Date: Tue, 07 Jul 2015 09:10:36 +0200 Subject: [RFC v2 3/6] irq: bypass: Extend skeleton for ARM forwarding control In-Reply-To: <559ABDC5.3060200@redhat.com> References: <1436184692-20927-1-git-send-email-eric.auger@linaro.org> <1436184692-20927-4-git-send-email-eric.auger@linaro.org> <559A7425.4050506@redhat.com> <559AA02A.6060703@linaro.org> <559AA552.3010400@redhat.com> <559AB62C.9000503@linaro.org> <559ABDC5.3060200@redhat.com> Message-ID: <559B7B6C.3060900@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 07/06/2015 07:41 PM, Paolo Bonzini wrote: > > > On 06/07/2015 19:09, Eric Auger wrote: >>>> The good thing is that this helps a bit forming a lock hierarchy across >>>> the subsystems, for example irq bypass mutex outside vfio_platform_irq >>>> spinlock, because you cannot have a spinlock inside the mutex. I think >>>> that all of your six callbacks are fine. >> arghh, no that's wrong then. I have plenty of them in the KVM/arm vgic >> part :-( > > I checked and it's right... > > /me rereads > > AAAARGH. You cannot have a mutex inside a spinlock. What you're doing > is fine. Sweated up (+ heat wave in France). Was about to read again the "concurrency and race conditions" chapter of the linux driver bible. Might be worth anyway ;-) Many thanks for the review Eric > > Paolo >