From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH v7 4/5] xen/arm: add SGI handling for GICv3 Date: Fri, 11 Jul 2014 15:12:45 +0100 Message-ID: <53BFF0DD.7090801@linaro.org> References: <1405083092-20216-1-git-send-email-vijay.kilari@gmail.com> <1405083092-20216-5-git-send-email-vijay.kilari@gmail.com> <53BFE9E8.4050902@linaro.org> <1405087714.27875.13.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1405087714.27875.13.camel@kazak.uk.xensource.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 Cc: vijay.kilari@gmail.com, stefano.stabellini@eu.citrix.com, Prasun.Kapoor@caviumnetworks.com, vijaya.kumar@caviumnetworks.com, tim@xen.org, xen-devel@lists.xen.org, stefano.stabellini@citrix.com, manish.jaggi@caviumnetworks.com List-Id: xen-devel@lists.xenproject.org On 07/11/2014 03:08 PM, Ian Campbell wrote: > On Fri, 2014-07-11 at 14:43 +0100, Julien Grall wrote: >>> diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c >>> index 3647497..e15d509 100644 >>> --- a/xen/arch/arm/vgic.c >>> +++ b/xen/arch/arm/vgic.c >>> @@ -343,6 +343,13 @@ out: >>> smp_send_event_check_mask(cpumask_of(v->processor)); >>> } >>> >>> +int vgic_emulate(struct cpu_user_regs *regs, union hsr hsr) >>> +{ >>> + struct vcpu *v = current; >>> + >>> + return v->domain->arch.vgic.handler->emulate_sysreg(regs, hsr); >>> +} >>> + >> >> You didn't implement emulate_sysreg for vgic-v2. If the GICv3 is >> misprogrammed, Xen will segfault... > > Which isn't all that different to the BUG_ON(!->emulate_sysreg) which I > would be in favour of, since misprogramming the GIC is a coding error... I expect this function to be called often (everytime the guest is sending an SGI), so adding BUG_ON(!->emulate_sysreg) will "slow down" the emulation. Implementing the callback emulate_sysreg for vgic-v2 and adding BUG inside would be another solution. Regards, -- Julien Grall