From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [Xen-devel] [PATCH] x86/amd: fix crash as Xen Dom0 on AMD Trinity systems Date: Wed, 30 May 2012 10:39:38 -0400 Message-ID: <20120530143937.GF3207@phenom.dumpdata.com> References: <1338383402-3838-1-git-send-email-andre.przywara@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1338383402-3838-1-git-send-email-andre.przywara@amd.com> Sender: linux-kernel-owner@vger.kernel.org To: Andre Przywara Cc: mingo@elte.hu, hpa@zytor.com, tglx@linutronix.de, jeremy@goop.org, xen-devel@lists.xensource.com, stable@vger.kernel.org#3.4+, linux-kernel@vger.kernel.org List-Id: xen-devel@lists.xenproject.org On Wed, May 30, 2012 at 03:10:02PM +0200, 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. > This fixes a crash when using the kernel as a Xen Dom0 on affected > Trinity systems. The wrmsrl_amd_safe is not properly paravirtualized > yet (this will be fixed in another patch). So with a rdmsrl_amd_safe and wrmsrl_amd_safe being implemented in the pv_cpu_ops - would this patch even be neccessary? > > Signed-off-by: Andre Przywara > Cc: stable@vger.kernel.org # 3.4+ > --- > arch/x86/kernel/cpu/amd.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c > index 146bb62..80ccd99 100644 > --- a/arch/x86/kernel/cpu/amd.c > +++ b/arch/x86/kernel/cpu/amd.c > @@ -586,9 +586,9 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c) > !cpu_has(c, X86_FEATURE_TOPOEXT)) { > u64 val; > > - if (!rdmsrl_amd_safe(0xc0011005, &val)) { > + if (!rdmsrl_safe(0xc0011005, &val)) { > val |= 1ULL << 54; > - wrmsrl_amd_safe(0xc0011005, val); > + checking_wrmsrl(0xc0011005, val); > rdmsrl(0xc0011005, val); > if (val & (1ULL << 54)) { > set_cpu_cap(c, X86_FEATURE_TOPOEXT); > -- > 1.7.4.4 > > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel