From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH] xen/arm64: Avoid sending SGI when kicking secondary cpus with spin_table Date: Wed, 8 Apr 2015 13:23:13 +0100 Message-ID: <55251DB1.6050504@citrix.com> References: <1428392032-11551-1-git-send-email-cbz@baozis.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1428392032-11551-1-git-send-email-cbz@baozis.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Chen Baozi , xen-devel@lists.xen.org Cc: Chen Baozi , julien.grall@linaro.org, ian.campbell@citrix.com List-Id: xen-devel@lists.xenproject.org Hi Chen, Subject: I think you can drop the "_" in spin_table. On 07/04/15 08:33, Chen Baozi wrote: > From: Chen Baozi > > On arm64, either firmware or xen's smp_up_cpu gate uses WFE on secondary > cpus to stand-by when booting. Thus, using SEV is enough for the boot > cpu to kick other secondaries. Further more, the current implementation > of cpu_up_send_sgi would pass a NULL cpumask pointer to send_SGI, which > then lead a data fault on GICv3 send_SGI implementation. I'm not familiar with spin table on ARM64, so I will let Ian answer about it. Aside that, the GICv3 implementation looks buggy to me. The GIC code provides two helpers which lead to pass NULL to the callback send_SGI: - send_SGI_self: AFAICT nobody is using it - send_SGI_allbutself: Only used by the smp boot code I think the former can be dropped or modify to send_SGI_one. For the later, I can't find why we need to send an SGI on ARM too. Ian, Stefano, any idea? Regards. -- Julien Grall