From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: xen: arm: beginning the removal of mode_switch.S Date: Wed, 21 Aug 2013 13:36:12 +0100 Message-ID: <5214B43C.7090807@citrix.com> References: <1376567483.9273.153.camel@hastur.hellion.org.uk> <520D0A72.1070501@citrix.com> <1376599896.9273.219.camel@hastur.hellion.org.uk> <520DFAF8.3030408@citrix.com> <1376665472.12491.20.camel@hastur.hellion.org.uk> <520E48DE.5080802@citrix.com> <1377007861.9517.52.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: <1377007861.9517.52.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: Tim Deegan , Chen Baozi , Stefano Stabellini , Andre Przywara , xen-devel List-Id: xen-devel@lists.xenproject.org On 08/20/2013 03:11 PM, Ian Campbell wrote: > So this is all pretty complex (not to mention hard to describe in ASCII) > and in lockstep, the secondary cpus wait twice once on the original > smp_cpu_up and then again on the relocated version. There is a subtle > reliance on the 1:1 mapping being retained in the original copy of the > page tables. Thanks for this ASCII! > I think the original wait is actually a workaround for lack of firmware > on the fastmodels, and should be implemented by either the firmware or > bootwrapper. BTW, this wait is an issue when the boot CPU ID is not equal to 0. I gave a quick try to move kick cpus after the HYP mode switch in assembly and I'm unable to boot secondary cpus on the Versatile Express. I guess, on the VE secondary cpus can only be "kick" in secure mode. Cheers, -- Julien Grall