From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Auger Subject: Re: [RFC v2 3/6] irq: bypass: Extend skeleton for ARM forwarding control Date: Tue, 07 Jul 2015 09:10:36 +0200 Message-ID: <559B7B6C.3060900@linaro.org> 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> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, patches@linaro.org 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 Return-path: In-Reply-To: <559ABDC5.3060200@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu List-Id: kvm.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 >