From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: Re: [PATCH] Fix emergency_restart (sysrq-b) with kvm loaded on Intel hosts Date: Mon, 25 Aug 2008 06:14:35 -0700 Message-ID: References: <1219655506-27418-1-git-send-email-avi@qumranet.com> <20080825091508.GC9114@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Avi Kivity , linux-kernel@vger.kernel.org, kvm@vger.kernel.org To: Ingo Molnar Return-path: Received: from out01.mta.xmission.com ([166.70.13.231]:51877 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753434AbYHYNYJ (ORCPT ); Mon, 25 Aug 2008 09:24:09 -0400 In-Reply-To: <20080825091508.GC9114@elte.hu> (Ingo Molnar's message of "Mon, 25 Aug 2008 11:15:08 +0200") Sender: kvm-owner@vger.kernel.org List-ID: Ingo Molnar writes: > * Avi Kivity wrote: > >> Enabling Intel VT has the curious side effect whereby the INIT signal >> is blocked. Rather than comment on the wisdom of this side effect, >> this patch adds an emergency restart reboot notifier, and modifies the >> kvm reboot notifier to disable VT on emergency reboot. Please no notifiers in emergency_restart. First emergency_restart is not supposed to work reliably it is a best effort tickle the hardware thing. Second and more importantly whenever someone adds a notifier instead of a proper hook to one a code path like this it seems like avoiding building a proper interface so and I believe keeps us from getting all of the logic and the heuristics right. Why not just add a disable intel_vt if it is enabled call? Eric