From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Egger Subject: Re: [PATCH] nestedhvm: ASID emulation Date: Fri, 15 Apr 2011 10:20:22 +0200 Message-ID: <4DA7FFC6.3080702@amd.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser Cc: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org On 04/14/11 16:43, Keir Fraser wrote: > On 14/04/2011 15:01, "Christoph Egger" wrote: > >>> What if some other vcpu's nv_n1asid or nv_n2asid got assigned the same HW >>> asid in this generation as this vcpu's (now stale, as it's from a previous >>> generation's) nv_n2asid? This PCPU can be interleaving execution of other >>> HVM VCPUs after all. >> >> I am not sure if I got you right. You mean what if two vcpus run on one >> physical cpu? In this case svm_do_resume() calls hvm_asid_flush_vcpu() >> before so that asid_generation and core_asid_generation do not match and >> a new asid is always assigned. > > No, it only does that if a given VCPU gets scheduled onto a *different* PCPU > than last time it ran. > > I've attached a mostly rewritten version of your patch that is about half > the size and I believe has a fighting chance of being correct (however it is > only build tested). Give it a look and a spin. Yes, it is correct. I like the idea to maintain a generation per asid. Please apply it. Thanks for this work. Christoph -- ---to satisfy European Law for business letters: Advanced Micro Devices GmbH Einsteinring 24, 85689 Dornach b. Muenchen Geschaeftsfuehrer: Alberto Bozzo, Andrew Bowd Sitz: Dornach, Gemeinde Aschheim, Landkreis Muenchen Registergericht Muenchen, HRB Nr. 43632