Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754133AbaDWI5w (ORCPT ); Wed, 23 Apr 2014 04:57:52 -0400 Received: from nat28.tlf.novell.com ([130.57.49.28]:44609 "EHLO nat28.tlf.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753815AbaDWI5o convert rfc822-to-8bit (ORCPT ); Wed, 23 Apr 2014 04:57:44 -0400 Message-Id: <53579CA4020000780000B342@nat28.tlf.novell.com> X-Mailer: Novell GroupWise Internet Agent 14.0.0 Date: Wed, 23 Apr 2014 09:57:40 +0100 From: "Jan Beulich" To: "Konrad Rzeszutek Wilk" Cc: , , , , , Subject: Re: [XEN PATCH 1/2] hvm: Support more than 32 VCPUS when migrating. References: <1396859560.22845.4.camel@kazak.uk.xensource.com> <1396977950-8789-1-git-send-email-konrad@kernel.org> <1396977950-8789-2-git-send-email-konrad@kernel.org> <534529A40200007800007055@nat28.tlf.novell.com> <20140409152706.GF5860@phenom.dumpdata.com> <5345853502000078000074F8@nat28.tlf.novell.com> <20140422183443.GA6817@phenom.dumpdata.com> In-Reply-To: <20140422183443.GA6817@phenom.dumpdata.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>> On 22.04.14 at 20:34, wrote: > With this patch: > [...] > And with an HVM guest poking at the rest of VCPUOPs: VCPUOP_get_physid, > VCPUOP_initialise, and VCPUOP_send_nmi - either before the CPU is up or > when it is up - work. > > That is: the VCPUOP_get_physid would return -EINVAL; VCPUOP_initialise > would return either -EEXIST or 0, and in either case > the content of the ctxt was full of zeros. Good. > The VCPUOP_send_nmi did cause the HVM to get an NMI and it spitted out > 'Dazed and confused'. It also noticed corruption: > > [ 3.611742] Corrupted low memory at c000fffc (fffc phys) = 00029b00 > [ 2.386785] Corrupted low memory at ffff88000000fff8 (fff8 phys) = > 2990000000000 > > Which is odd because there does not seem to be anything in the path > of hypervisor that would cause this. Indeed. This looks a little like a segment descriptor got modified here with a descriptor table base of zero and a selector of 0xfff8. That corruption needs to be hunted down in any case before enabling VCPUOP_send_nmi for HVM. Jan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/