From mboxrd@z Thu Jan 1 00:00:00 1970 From: Borislav Petkov Subject: Re: [PATCH] x86/amd: fix crash as Xen Dom0 on AMD Trinity systems Date: Wed, 30 May 2012 16:55:23 +0200 Message-ID: <20120530145523.GA15635@x1.osrc.amd.com> References: <1338383402-3838-1-git-send-email-andre.przywara@amd.com> <4FC631D3.9080907@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <4FC631D3.9080907@zytor.com> Sender: linux-kernel-owner@vger.kernel.org To: "H. Peter Anvin" Cc: Andre Przywara , mingo@elte.hu, tglx@linutronix.de, konrad.wilk@oracle.com, jeremy@goop.org, linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com, stable@vger.kernel.org.#.3.4+ List-Id: xen-devel@lists.xenproject.org On Wed, May 30, 2012 at 07:42:27AM -0700, H. Peter Anvin wrote: > On 05/30/2012 06:10 AM, Andre Przywara wrote: > > Because we are behind a family check before tweaking the topology > > bit, we can use the standard rd/wrmsr variants for the CPUID feature > > register. > > That is not what the *msr*_amd*() functions do. > > NAK. This is a totally bogus patch. The *msr*_amd*() variants were used instead of the normal *msrl_safe variants although the AMD variants weren't needed there at all. This has no issue on baremetal but breaks xen and this is how we caught this. So the patch corrects the original patch so that xen is happy too. -- Regards/Gruss, Boris.