From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH] KVM: arm64: add workaround for Cortex-A57 erratum #852523 Date: Tue, 15 Sep 2015 00:08:10 +0100 Message-ID: <55F7535A.3020905@citrix.com> References: <1442243163-2675-1-git-send-email-will.deacon@arm.com> <1442244988.3549.313.camel@citrix.com> <20150914155854.GF23878@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1Zbcr8-0000Sl-VX for xen-devel@lists.xenproject.org; Mon, 14 Sep 2015 23:08:15 +0000 In-Reply-To: <20150914155854.GF23878@arm.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: Marc Zyngier , "xen-devel@lists.xenproject.org" , Will Deacon List-Id: xen-devel@lists.xenproject.org On 14/09/2015 16:58, Will Deacon wrote: >> The Xen ctxt switch code[0] has DACR_EL2 in the midst of it all, and >> certainly followed by some sysregs, which I've got my fingers crossed >> happens to be sufficient (other than maybe adding a comment). > > It looks like you restore CONTEXTIDR_EL1 fairly late, so you should be > ok. It may be worth to have a comment in the code explaining the errata to avoid introduce by inadvertence if we plan to re-order the context switch. I can send a patch for that. Regards, -- Julien Grall