From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH v2 0/2] kvm: x86: Emulate MSR_PLATFORM_INFO Date: Tue, 18 Jun 2013 16:05:08 +0200 Message-ID: <51C06914.1090904@redhat.com> References: <1370361738-4277-1-git-send-email-bsd@redhat.com> <20130605084213.GQ4725@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Bandan Das , kvm@vger.kernel.org, Marcelo Tosatti , "Nakajima, Jun" To: Gleb Natapov Return-path: Received: from mx1.redhat.com ([209.132.183.28]:34642 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932822Ab3FROFO (ORCPT ); Tue, 18 Jun 2013 10:05:14 -0400 In-Reply-To: <20130605084213.GQ4725@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Il 05/06/2013 10:42, Gleb Natapov ha scritto: >> > These patches add an emulated MSR_PLATFORM_INFO that kvm guests >> > can read as described in section 14.3.2.4 of the Intel SDM. >> > The relevant changes and details are in [2/2]; [1/2] makes vendor_intel >> > generic. There are atleat two known applications that fail to run because >> > of this MSR missing - Sandra and vTune. > So I really want Intel opinion on this. Right now it is impossible to > implement the MSR correctly in the face of migration (may be with tsc > scaling it will be possible) and while it is unimplemented if application > tries to use it it fails, but if we will implement it application will > just produce incorrect result without any means for user to detect it. Jun, ping? (Perhaps Gleb you want to ask a more specific question though). I don't think this is much different from any other RDTSC usage in applications (they will typically do their calibration manually, and do it just once). I'm applying it to queue. Paolo