From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH v2 for-4.5] xen/arm: clear UIE on hypervisor entry Date: Thu, 20 Nov 2014 16:46:27 +0000 Message-ID: <546E1AE3.4050409@linaro.org> References: <1416480804-25651-1-git-send-email-stefano.stabellini@eu.citrix.com> <546DCA3F.2030508@linaro.org> <546DCB30.6040400@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Stefano Stabellini Cc: julien.grall@citrix.com, xen-devel@lists.xensource.com, Ian.Campbell@citrix.com, andrii.tseglytskyi@globallogic.com List-Id: xen-devel@lists.xenproject.org Hi Stefano, On 11/20/2014 03:54 PM, Stefano Stabellini wrote: > On Thu, 20 Nov 2014, Julien Grall wrote: >> On 11/20/2014 11:02 AM, Julien Grall wrote: >>> Hi Stefano, >>> >>> On 11/20/2014 10:53 AM, Stefano Stabellini wrote: >>>> UIE being set can cause maintenance interrupts to occur when Xen writes >>>> to one or more LR registers. The effect is a busy loop around the >>>> interrupt handler in Xen >>>> (http://marc.info/?l=xen-devel&m=141597517132682): everything gets stuck. >>>> >>>> Signed-off-by: Stefano Stabellini >>>> Reported-and-Tested-by: Andrii Tseglytskyi >>>> CC: konrad.wilk@oracle.com >>>> --- >>>> >>>> Konrad, this fixes an actual bug, at least on OMAP5. It should have no >>>> bad side effects on any other platforms as far as I can tell. It should >>>> go in 4.5. >>> >>> From Andrii's mail, there is a bad side effect. We can receive spurious >>> interrupt. >>> >>> On V1, you said that you tried this patch on midway. I would prefer if >>> you give a try on platform that would really be used (such as xgene or >>> seattle). As we know Midway won't be used in prod. >> >> And maybe give a try to gicv3 too as it's common code. > > I don't have a gicv3 test environment ready but it works on xgene too Ok. I will give a quick try on the model today or tomorrow. Aside from that, and after reading the spec. This patch looks good to me: Reviewed-by: Julien Grall Regards, -- Julien Grall