From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andre Przywara Subject: Re: Booting/installing WindowsNT Date: Wed, 5 May 2010 10:53:01 +0200 Message-ID: <4BE131ED.6050906@amd.com> References: <4BDB44C2.7090204@msgid.tls.msk.ru> <4BDB4E58.50805@msgid.tls.msk.ru> <4BDD4E32.2080503@redhat.com> <4BDDA455.8090001@msgid.tls.msk.ru> <4BDE882F.5000009@amd.com> <4BDE8DF4.8070604@redhat.com> <4BDE9757.8090809@amd.com> <4BDF01CA.80505@msgid.tls.msk.ru> <4BDFE3A7.2050706@redhat.com> <4BE00E2A.2010901@amd.com> <4BE015BF.2010401@msgid.tls.msk.ru> <4BE03CD7.8090105@amd.com> <4BE049F5.4000500@redhat.com> <4BE12D1E.5000602@amd.com> <4BE12F26.9050502@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: Michael Tokarev , KVM list To: Avi Kivity Return-path: Received: from va3ehsobe005.messaging.microsoft.com ([216.32.180.15]:38062 "EHLO VA3EHSOBE006.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933644Ab0EEIxd (ORCPT ); Wed, 5 May 2010 04:53:33 -0400 In-Reply-To: <4BE12F26.9050502@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Avi Kivity wrote: > On 05/05/2010 11:32 AM, Andre Przywara wrote: >> Avi Kivity wrote: >>> On 05/04/2010 06:27 PM, Andre Przywara wrote: >>>> >>>>> 3. In all other cases so far it BSoDs with STOP 0x3E error >>>>> right before displaying that kernel message. >>>> MSDN talks about a mulitprocessor configuration error: >>>> http://msdn.microsoft.com/en-us/library/ms819006.aspx >>>> I suspected the offline CPUs in the mptable that confuse NT. But >>>> -smp 1,maxcpus=1 does not make a difference. I will try to dig >>>> deeper in this area. >> OK, I tackled this down. It is the max CPUID level that differs. >> In the AMD CPUID guide leafs 0000_0002 till 0000_0004 are reserved, >> the CPU that Michael and I used (K8RevF) actually have a max leaf of 1 >> here. >> Default qemu64 has a max leaf of 4. >> So by saying -cpu qemu64,level=1 (or 2 or 3) it works for me. >> Modern OS only read leaf 4 on Intel systems, it seems that NT4 is >> missing this. >> I will now think about a proper fix for this. > > I don't understand. Shouldn't the values for cpuid leaf 4 be the same > for qemu64 whether the cpu is Intel or AMD? The real cpuid shouldn't > matter. Yes, but if the max leaf value is smaller than 4, then the guest will not read it. It seems that NT does not like the entries returned by KVM for leaf 4. I am about to find out what exactly is causing that. I have the theory that the stop is intentional as NT4 workstation does not _want_ to support certain SMP configurations (more than 2 processors?) I have seen similar issue with WinXPPro and -smp 4 (which went away with -smp 4,cores=4). Regards, Andre. -- Andre Przywara AMD-Operating System Research Center (OSRC), Dresden, Germany Tel: +49 351 448-3567-12