From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [V7 PATCH 5/7] pvh: change xsm_add_to_physmap Date: Sun, 09 Feb 2014 16:51:31 +0000 Message-ID: <52F7B213.3000302@linaro.org> References: <1387247911-28846-1-git-send-email-mukesh.rathor@oracle.com> <1387247911-28846-6-git-send-email-mukesh.rathor@oracle.com> <20140127175550.4cc67171@mantra.us.oracle.com> <52E7951802000078001177F6@nat28.tlf.novell.com> <20140128180802.152b3f8d@mantra.us.oracle.com> <1390992026.31814.63.camel@kazak.uk.xensource.com> <20140129113846.GA54797@deinos.phlegethon.org> <1390995662.31814.76.camel@kazak.uk.xensource.com> <20140129114837.GB54797@deinos.phlegethon.org> <1390996295.31814.84.camel@kazak.uk.xensource.com> <20140129173315.592e593e@mantra.us.oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1WCXbT-00029M-T9 for xen-devel@lists.xenproject.org; Sun, 09 Feb 2014 16:51:36 +0000 Received: by mail-we0-f177.google.com with SMTP id t61so3616042wes.36 for ; Sun, 09 Feb 2014 08:51:33 -0800 (PST) In-Reply-To: <20140129173315.592e593e@mantra.us.oracle.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: Mukesh Rathor , Ian Campbell Cc: xen-devel , Tim Deegan , Jan Beulich , "stefano.stabellini@eu.citrix.com" List-Id: xen-devel@lists.xenproject.org Hello Mukesh, On 30/01/14 01:33, Mukesh Rathor wrote: >>> I'm not sure what you mean: >>> - the code that Mukesh is adding doesn't have a struct page, it's >>> just grabbing the foreign domid from the hypercall arg; >>> - if we did have a struct page, we'd just need to take a ref to >>> stop the owner changing underfoot; and >>> - get_pg_owner() takes a domid anyway. >> >> Sorry, I was confused/mislead by the name... >> >> rcu_lock_live_remote_domain_by_id does look like what is needed. Following the xentrace tread: http://www.gossamer-threads.com/lists/xen/devel/315883, rcu_lock_live_remote_domain_by_id will not correctly works. On Xen on ARM, xentrace is using this hypercall to map XEN page (via DOMID_XEN). In this case, rcu_lock_*domain* will always fails which will prevent xentrace to works on Xen on ARM (and on PVH). Regards, -- Julien Grall