From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Egger Subject: Re: [PATCH 2/2] Xen/vMCE: bugfix to remove problematic is_vmce_ready check Date: Mon, 13 May 2013 16:24:14 +0200 Message-ID: <5190F78E.4000207@amazon.de> References: <51878E9A02000078000D36C8@nat28.tlf.novell.com> <51877AB0.1060802@amazon.de> <51879645.8080803@amazon.de> <5187C6DE.2020304@amazon.de> <5187CCD9.9030801@amazon.de> <5188E8D1.7060009@amazon.de> <518CFD26.7070200@amazon.de> <5190A7B8.7020002@amazon.de> <5190CA01.9010505@amazon.de> 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: "Liu, Jinsong" Cc: Jan Beulich , xen-devel List-Id: xen-devel@lists.xenproject.org On 13.05.13 15:35, Liu, Jinsong wrote: > Christoph Egger wrote: >> On 13.05.13 12:44, Liu, Jinsong wrote: >>>>> Please refer to the description of patch 2/2, especially >>>>> >>>>> * For dom0, if really need check, it should check whether vMCE >>>>> injection for dom0 ready (say, exception trap bounce check, >>>>> which has been done at inject_vmce()), not check dom0 mcelog >>>>> ready (which has been done at mce_softirq() before send global >>>>> virq to dom0). >>>>> >>>>> Which means before hypervisor send error log via virq to dom0, >>>>> current code has checked whether mcelog ready at dom0 or not --> >>>>> that's the right place for your concern, and it has indeed done >>>>> check. >>>> >>>> I think, I do not understand the patch description. >>>> Let me rephrase if I do now due to this discussion: >>>> >>>> The mcelog driver in Dom0 registers itself to the virq handler to >>>> provide the machine check logging service. >>> >>> Yes. >>> >>>> Xen checks if a virq handler has been registered >>> >>> Yes. >>> >>>> but does not check >>>> if the dom0 handler is actually ready to take the errors. >>>> This patch fixes this. >>>> >>> >>> I'm not clear your question 'does not check if the dom0 handler >>> is actually ready to take the errors'. Could you elaborate more your >>> concern at this point? >> >> Yes, this is exactly my question. You got it. >> >> Christoph > > Hmm, seems you misunderstand my word. What I meant is, > I don't know what you are asking by 'does not check if the dom0 handler is actually ready to take the errors'. > Could you elaborate more your question? I reread your patch description: > * For dom0, if really need check, it should check whether vMCE ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > injection for dom0 ready (say, exception trap bounce check, which ^^^^^^^^^^^^^^^^^^^^^^^^ > has been done at inject_vmce()), not check dom0 mcelog ready (which > ^^^^^^^^^^^^^^^^^^^^^^^^^^^ > has been done at mce_softirq() before send global virq to dom0). My question is: Is it possible when mcelog driver registers the virq handler that it cannot deal with machine check errors immediately? Christoph