From mboxrd@z Thu Jan 1 00:00:00 1970 From: Meng Xu Subject: Re: Question about the CAT and CMT in Xen Date: Tue, 1 Sep 2015 08:55:54 -0400 Message-ID: References: <55E49C11.40303@citrix.com> <20150901054716.GA19417@pengc-linux.bj.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150901054716.GA19417@pengc-linux.bj.intel.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Chao Peng Cc: Andrew Cooper , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org 2015-09-01 1:47 GMT-04:00 Chao Peng : > On Mon, Aug 31, 2015 at 04:09:31PM -0400, Meng Xu wrote: >> I looked into the xen/arch/x86/psr.c and found that the function >> cat_cpu_init() just returned without initializing the variable >> "cat_socket_enable". >> >> Both !cpu_has(c, X86_FEATURE_CAT) and c->cpuid_level < >> PSR_CPUID_LEVEL_CAT are evaluated as 1 inside the function >> cat_cpu_init(). >> >> OK. I understand that the cpuid info shows that the CPU does not >> support CAT. However, according to the table at >> http://www.intel.com/content/www/us/en/communications/cache-monitoring-cache-allocation-technologies.html, >> Intel(R) Xeon(R) CPU E5-2618L v3 should support CAT. >> >> I'm not sure which part is incorrect: the hardware or the software? >> (Hope Chao could give some insight about this.) >> > > Hmmm, from cpuid info it looks like this model does not support CAT. I'm > not sure which microarchitecture it is. According to http://www.cpu-world.com/CPUs/Xeon/Intel-Xeon%20E5-2618L%20v3.html, 2618L v3 is Haswell. :-( > But if it is broadwell, hardware > should support that, what you need is some fireware update, just as Andrew > has said. But otherwise it is haswell, then the hardware probably doesn't > support that. In that case the above link probably is also wrong. I can check > that internally. Ah, could you please let me know if the link[1] is wrong? If it does not support CAT, I'm screwed. :'-( [1] http://www.intel.com/content/www/us/en/communications/cache-monitoring-cache-allocation-technologies.html > > Chao -- ----------- Meng Xu PhD Student in Computer and Information Science University of Pennsylvania http://www.cis.upenn.edu/~mengxu/