From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: [PATCH 15/15] Revert "x86: default to reboot via ACPI" Date: Sun, 9 Nov 2008 10:24:23 +0000 Message-ID: <20081109102423.GA13217@srcf.ucam.org> References: <1225915018-6548-1-git-send-email-ehabkost@redhat.com> <20081106143021.GD13023@elte.hu> <20081106150610.GA1644@elte.hu> <200811061853.08003.arvidjaar@mail.ru> <20081106215011.GA6391@srcf.ucam.org> <1226019679.3989.107.camel@yakui_zhao.sh.intel.com> <20081107005946.GA9254@srcf.ucam.org> <4916B737.7050107@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Zhao Yakui , Len Brown , Andrey Borzenkov , Ingo Molnar , Eduardo Habkost , "Eric W. Biederman" , Andrew Morton , "Rafael J. Wysocki" , "kexec@lists.infradead.org" , "kvm@vger.kernel.org" , Linux Kernel Mailing List , "linux-acpi@vger.kernel.org" To: Avi Kivity Return-path: Content-Disposition: inline In-Reply-To: <4916B737.7050107@redhat.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Sun, Nov 09, 2008 at 12:11:03PM +0200, Avi Kivity wrote: > Matthew Garrett wrote: > >Hmm. But we're seeing some machines that end up very confused if > >rebooted via ACPI. I guess we need to run Vista on them to find out how > >they behave. What OSI strings did your KVM setup expose? We know that > >Windows changes behaviour under various circumstances depending on which > >OS the firmware requests, so it's almost possible that this is another > >of those cases. > > > > Isn't it the other way around? The firmware changes behavior depending > on how the OS identifies itself? That also happens, yes. > Reboot is a fixed feature IIRC, so it cannot change depending on > identification strings. The ID strings that the firmware requests give a good idea about which operating systems the machine has been tested with. If Vista uses the ACPI method then having the firmware request the OSI string for Vista gives us a good indication that it's safe to use the ACPI method. -- Matthew Garrett | mjg59@srcf.ucam.org