From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51ADCC43A1D for ; Thu, 12 Jul 2018 11:23:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0DBAF20BF2 for ; Thu, 12 Jul 2018 11:23:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0DBAF20BF2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726650AbeGLLcT (ORCPT ); Thu, 12 Jul 2018 07:32:19 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:46286 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726492AbeGLLcT (ORCPT ); Thu, 12 Jul 2018 07:32:19 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 07F3981663FF; Thu, 12 Jul 2018 11:23:12 +0000 (UTC) Received: from vitty.brq.redhat.com.redhat.com (unknown [10.43.2.155]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9020116874; Thu, 12 Jul 2018 11:23:10 +0000 (UTC) From: Vitaly Kuznetsov To: Wanpeng Li Cc: kvm , Paolo Bonzini , Radim Krcmar , "the arch\/x86 maintainers" , Andy Lutomirski , ldv@altlinux.org, yamato@redhat.com, LKML Subject: Re: [PATCH] x86/kvm/vmx: don't read current->thread.{fs,gs}base of legacy tasks References: <20180711173718.8850-1-vkuznets@redhat.com> <877em0ztoi.fsf@vitty.brq.redhat.com> Date: Thu, 12 Jul 2018 13:23:09 +0200 In-Reply-To: <877em0ztoi.fsf@vitty.brq.redhat.com> (Vitaly Kuznetsov's message of "Thu, 12 Jul 2018 11:31:41 +0200") Message-ID: <87h8l4y9ya.fsf@vitty.brq.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Thu, 12 Jul 2018 11:23:12 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Thu, 12 Jul 2018 11:23:12 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'vkuznets@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Vitaly Kuznetsov writes: > Wanpeng Li writes: > >> Test suite: MSR switch >> PASS: VM entry MSR load >> PASS: VM exit MSR store >> PASS: VM exit MSR load >> FAIL: VM entry MSR load: try to load FS_BASE >> SUMMARY: 4 tests, 1 unexpected failures >> >> kvm-unit-tests fails w/ and w/o the patch, maybe it is another issue, >> i didn't dig further, you can have a look if you are interested in. :) > > The patch only changes the behavior for legacy userspaces and I can > reproduce the failure on native x86_64, it is something different. I'm, > however, interested so stay tuned :-) Yes, the regression was introduced by commit e79f245ddec17bbd89d73cd0169dba4be46c9b55 Author: KarimAllah Ahmed Date: Sat Apr 14 05:10:52 2018 +0200 X86/KVM: Properly update 'tsc_offset' to represent the running guest basically, when nested_vmx_load_msr() fails we don't set exit_qualification accordingly. The fix is simple: @@ -11720,8 +11721,10 @@ static int enter_vmx_non_root_mode(struct kvm_vcpu *vcpu) msr_entry_idx = nested_vmx_load_msr(vcpu, vmcs12->vm_entry_msr_load_addr, vmcs12->vm_entry_msr_load_count); - if (msr_entry_idx) + if (msr_entry_idx) { + exit_qual = msr_entry_idx; goto fail; + } /* * Note no nested_vmx_succeed or nested_vmx_fail here. At this point I'll be sending a patch out shortly. But this is completely orthogonal to the 'legacy' issue ;-) -- Vitaly