From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH v2] KVM: Synthesize G bit for all segments. Date: Thu, 10 Jul 2014 14:27:24 +0200 Message-ID: <53BE86AC.4090308@redhat.com> References: <1404729492.30313.803.camel@akataria-dtop.eng.vmware.com> <53BA9AD0.9030306@redhat.com> <1404793061.30313.1874.camel@akataria-dtop.eng.vmware.com> <53BE551C.7090304@siemens.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, Joerg Roedel , Gleb Natapov , the arch/x86 maintainers , jmattson@vmware.com To: Jan Kiszka , Alok Kataria Return-path: Received: from mail-qg0-f52.google.com ([209.85.192.52]:32915 "EHLO mail-qg0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751484AbaGJM1h (ORCPT ); Thu, 10 Jul 2014 08:27:37 -0400 Received: by mail-qg0-f52.google.com with SMTP id f51so280074qge.11 for ; Thu, 10 Jul 2014 05:27:36 -0700 (PDT) In-Reply-To: <53BE551C.7090304@siemens.com> Sender: kvm-owner@vger.kernel.org List-ID: Il 10/07/2014 10:55, Jan Kiszka ha scritto: >> > + /* >> > + * SVM spec doesn't require the platform to track the G bit for all >> > + * segments, so similar to CS, let's synthesize this bit for all >> > + * segments. > Either I misunderstand the reference to CS or it does no longer apply > once the patch is in. I would suggest to remove that part of the sentence. Something like this: /* * The SVM spec doesn't require the platform to track the 'G' bit for * all segments. Current processors track it for all segments except * CS, but other hypervisors may not do so. So let's synthesize this * bit always to help running KVM nested. It also helps cross-vendor * migration, because Intel's vmentry has a check on the 'G' bit. */ Paolo