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=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 DC1CCC433DF for ; Mon, 17 Aug 2020 17:26:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B632720716 for ; Mon, 17 Aug 2020 17:26:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389823AbgHQRWi (ORCPT ); Mon, 17 Aug 2020 13:22:38 -0400 Received: from mga17.intel.com ([192.55.52.151]:61735 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389816AbgHQRWg (ORCPT ); Mon, 17 Aug 2020 13:22:36 -0400 IronPort-SDR: TAUe2uTwTVI6nPrDPM+SOMtrutA4JDauDBigh/U55F5qq9w9+97Q7BzZarL1C7Rn3NjAvft8TQ gm2SPDPrU8Rg== X-IronPort-AV: E=McAfee;i="6000,8403,9716"; a="134818255" X-IronPort-AV: E=Sophos;i="5.76,324,1592895600"; d="scan'208";a="134818255" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Aug 2020 10:22:35 -0700 IronPort-SDR: nEoLZbUtp34BoUYd5WmOxfMcLgAQPMgFE8tvVUJU8KClPVVBi0dLi9d3gco++TBY/fY3P1cqiZ TCzf3cLJNS9Q== X-IronPort-AV: E=Sophos;i="5.76,324,1592895600"; d="scan'208";a="292496184" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.160]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Aug 2020 10:22:34 -0700 Date: Mon, 17 Aug 2020 10:22:33 -0700 From: Sean Christopherson To: Mohammed Gamal Cc: kvm@vger.kernel.org, pbonzini@redhat.com, linux-kernel@vger.kernel.org, vkuznets@redhat.com, wanpengli@tencent.com, jmattson@google.com, joro@8bytes.org Subject: Re: [PATCH v3 7/9] KVM: VMX: Add guest physical address check in EPT violation and misconfig Message-ID: <20200817172233.GF22407@linux.intel.com> References: <20200710154811.418214-1-mgamal@redhat.com> <20200710154811.418214-8-mgamal@redhat.com> <20200715230006.GF12349@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200715230006.GF12349@linux.intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, Jul 15, 2020 at 04:00:08PM -0700, Sean Christopherson wrote: > On Fri, Jul 10, 2020 at 05:48:09PM +0200, Mohammed Gamal wrote: > > Check guest physical address against it's maximum physical memory. If > > the guest's physical address exceeds the maximum (i.e. has reserved bits > > set), inject a guest page fault with PFERR_RSVD_MASK set. > > > > This has to be done both in the EPT violation and page fault paths, as > > there are complications in both cases with respect to the computation > > of the correct error code. > > > > For EPT violations, unfortunately the only possibility is to emulate, > > because the access type in the exit qualification might refer to an > > access to a paging structure, rather than to the access performed by > > the program. > > > > Trapping page faults instead is needed in order to correct the error code, > > but the access type can be obtained from the original error code and > > passed to gva_to_gpa. The corrections required in the error code are > > subtle. For example, imagine that a PTE for a supervisor page has a reserved > > bit set. On a supervisor-mode access, the EPT violation path would trigger. > > However, on a user-mode access, the processor will not notice the reserved > > bit and not include PFERR_RSVD_MASK in the error code. > > > > Co-developed-by: Mohammed Gamal > > Signed-off-by: Paolo Bonzini > > --- > > arch/x86/kvm/vmx/vmx.c | 24 +++++++++++++++++++++--- > > arch/x86/kvm/vmx/vmx.h | 3 ++- > > 2 files changed, 23 insertions(+), 4 deletions(-) > > > > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > > index 770b090969fb..de3f436b2d32 100644 > > --- a/arch/x86/kvm/vmx/vmx.c > > +++ b/arch/x86/kvm/vmx/vmx.c > > @@ -4790,9 +4790,15 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu) > > > > if (is_page_fault(intr_info)) { > > cr2 = vmx_get_exit_qual(vcpu); > > - /* EPT won't cause page fault directly */ > > - WARN_ON_ONCE(!vcpu->arch.apf.host_apf_flags && enable_ept); > > - return kvm_handle_page_fault(vcpu, error_code, cr2, NULL, 0); > > + if (enable_ept && !vcpu->arch.apf.host_apf_flags) { > > + /* > > + * EPT will cause page fault only if we need to > > + * detect illegal GPAs. > > + */ > > + kvm_fixup_and_inject_pf_error(vcpu, cr2, error_code); > > This splats when running the PKU unit test, although the test still passed. > I haven't yet spent the brain power to determine if this is a benign warning, > i.e. simply unexpected, or if permission_fault() fault truly can't handle PK > faults. > > WARNING: CPU: 25 PID: 5465 at arch/x86/kvm/mmu.h:197 paging64_walk_addr_generic+0x594/0x750 [kvm] > Hardware name: Intel Corporation WilsonCity/WilsonCity, BIOS WLYDCRB1.SYS.0014.D62.2001092233 01/09/2020 > RIP: 0010:paging64_walk_addr_generic+0x594/0x750 [kvm] > Code: <0f> 0b e9 db fe ff ff 44 8b 43 04 4c 89 6c 24 30 8b 13 41 39 d0 89 > RSP: 0018:ff53778fc623fb60 EFLAGS: 00010202 > RAX: 0000000000000001 RBX: ff53778fc623fbf0 RCX: 0000000000000007 > RDX: 0000000000000001 RSI: 0000000000000002 RDI: ff4501efba818000 > RBP: 0000000000000020 R08: 0000000000000005 R09: 00000000004000e7 > R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000007 > R13: ff4501efba818388 R14: 10000000004000e7 R15: 0000000000000000 > FS: 00007f2dcf31a700(0000) GS:ff4501f1c8040000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000000 CR3: 0000001dea475005 CR4: 0000000000763ee0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > PKRU: 55555554 > Call Trace: > paging64_gva_to_gpa+0x3f/0xb0 [kvm] > kvm_fixup_and_inject_pf_error+0x48/0xa0 [kvm] > handle_exception_nmi+0x4fc/0x5b0 [kvm_intel] > kvm_arch_vcpu_ioctl_run+0x911/0x1c10 [kvm] > kvm_vcpu_ioctl+0x23e/0x5d0 [kvm] > ksys_ioctl+0x92/0xb0 > __x64_sys_ioctl+0x16/0x20 > do_syscall_64+0x3e/0xb0 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > ---[ end trace d17eb998aee991da ]--- Looks like this series got pulled for 5.9, has anyone looked into this?