From mboxrd@z Thu Jan 1 00:00:00 1970 From: Borislav Petkov Subject: Re: [Xen-devel] [PATCH] x86/amd: fix crash as Xen Dom0 on AMD Trinity systems Date: Wed, 30 May 2012 20:17:23 +0200 Message-ID: <20120530181722.GF15438@x1.osrc.amd.com> References: <4FC63DAF0200007800086DC5@nat28.tlf.novell.com> <4FC62888.9010407@amd.com> <20120530144851.GA12184@jshin-Toonie> <20120530145005.GI3207@phenom.dumpdata.com> <20120530150334.GA13349@jshin-Toonie> <20120530171754.GA5115@phenom.dumpdata.com> <20120530173247.GC15635@x1.osrc.amd.com> <4FC65D34.1060803@zytor.com> <20120530175150.GE15438@x1.osrc.amd.com> <4FC66037.6020506@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <4FC66037.6020506@zytor.com> Sender: linux-kernel-owner@vger.kernel.org To: "H. Peter Anvin" Cc: Konrad Rzeszutek Wilk , Jacob Shin , Andre Przywara , jeremy@goop.org, xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org, Jan Beulich , mingo@elte.hu, tglx@linutronix.de List-Id: xen-devel@lists.xenproject.org On Wed, May 30, 2012 at 11:00:23AM -0700, H. Peter Anvin wrote: > OK. But there is still the general problem, no? With this patch xen crashes go away because they paravirt native_{read,write}_msr_safe. The other place where we use the amd_safe variants is an obscure K8, revC and earlier fix for _some_ BIOSen and this hasn't bitten us yet so I'm assuming people haven't run xen on such boxes yet. Does it need fixing? Probably, if we really really have to. Now, someone probably needs to paravirt the *safe_regs variants in case something else decides to use them. I don't know what to do here, do I want more paravirt code in there? No. I guess if this is done carefully and cleanly, then it should be ok but it can't be done like that - it needs to adhere to the current pv_cpu_ops thing which is already there. Hmm... -- Regards/Gruss, Boris.