From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH v2 4/5] kvm: x86: mmu: Lockless access tracking for Intel CPUs without EPT A bits. Date: Wed, 30 Nov 2016 12:09:06 +0100 Message-ID: <3727cee4-9e92-de81-8bad-3a29fead47d1@redhat.com> References: <1857180.zXFPSRIdpL@js-desktop.mtv.corp.google.com> <634179352.518636.1480406971725.JavaMail.zimbra@redhat.com> <2379240.SuCdKK30l0@js-desktop.mtv.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Cc: kvm@vger.kernel.org, andreslc@google.com, pfeiner@google.com, guangrong xiao To: Junaid Shahid Return-path: Received: from mail-wj0-f196.google.com ([209.85.210.196]:33694 "EHLO mail-wj0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933043AbcK3LJL (ORCPT ); Wed, 30 Nov 2016 06:09:11 -0500 Received: by mail-wj0-f196.google.com with SMTP id kp2so21704510wjc.0 for ; Wed, 30 Nov 2016 03:09:10 -0800 (PST) In-Reply-To: <2379240.SuCdKK30l0@js-desktop.mtv.corp.google.com> Sender: kvm-owner@vger.kernel.org List-ID: On 30/11/2016 01:59, Junaid Shahid wrote: >> > >> > Fair enough, but add a comment to explain the error_code check because I >> > don't get it. :) > The error_code check verifies that it was a Read access, as PFERR_USER_MASK > is mapped to EPT_VIOLATION_READ. However, I have just realized that this isn’t > the case when not using EPT. So I’ll just use the following instead, which > works for both EPT and non-EPT: Looks good, thanks! Paolo