From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH kvm-unit-tests] vmx: fixes for MAXPHYADDR requirement Date: Thu, 25 Jan 2018 11:36:09 -0500 (EST) Message-ID: <1847212195.2581284.1516898169052.JavaMail.zimbra@redhat.com> References: <1516212225-37393-2-git-send-email-pbonzini@redhat.com> <20180125151132.GB19884@flask> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Cc: kvm@vger.kernel.org To: Radim =?utf-8?B?S3LEjW3DocWZ?= Return-path: Received: from mx1.redhat.com ([209.132.183.28]:59486 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751112AbeAYQgJ (ORCPT ); Thu, 25 Jan 2018 11:36:09 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id BF303A98A for ; Thu, 25 Jan 2018 16:36:09 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 689A96F13B for ; Thu, 25 Jan 2018 16:36:09 +0000 (UTC) In-Reply-To: <20180125151132.GB19884@flask> Sender: kvm-owner@vger.kernel.org List-ID: ----- Original Message ----- > From: "Radim Krčmář" > To: "Paolo Bonzini" > Cc: kvm@vger.kernel.org > Sent: Thursday, January 25, 2018 4:11:32 PM > Subject: Re: [PATCH kvm-unit-tests] vmx: fixes for MAXPHYADDR requirement > > 2018-01-17 19:03+0100, Paolo Bonzini: > > The EPT access tests require at least 41 bits of guest physical address > > space. This is because the test data needs a separate PML4 entry in the > > EPT table. However, many consumer-grade processors have only 36 or > > 39-bit MAXPHYADDR, and the tests fail there with a page fault due to > > reserved bits set in the guest (GVA->GPA) page tables. > > > > Add a test on MAXPHYADDR and skip the tests if they cannot run on the > > system under test, and only require 40 bits to lower the requirements. > > > > Signed-off-by: Paolo Bonzini > > --- > > x86/vmx_tests.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c > > index e8c97f2..0c3b5a7 100644 > > --- a/x86/vmx_tests.c > > +++ b/x86/vmx_tests.c > > @@ -2609,6 +2609,10 @@ static void ept_access_test_setup(void) > > if (setup_ept(false)) > > test_skip("EPT not supported"); > > > > + /* We use data->gpa = 1 << 39 so that test data has a separate pml4 entry > > */ > > + if (cpuid_maxphyaddr() < 40) > > This does not help at the moment -- QEMU reports 40 even on hosts that > don't have as much. It is a QEMU bug, so applied still, thanks. True. However, vmx.flat is run with "-cpu host,+vmx", and that should forward the host MAXPHYADDR, shouldn't it? Paolo