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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 CEC4EC433E0 for ; Wed, 20 May 2020 14:24:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D9A3207D3 for ; Wed, 20 May 2020 14:24:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726697AbgETOYv (ORCPT ); Wed, 20 May 2020 10:24:51 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33168 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727066AbgETOW2 (ORCPT ); Wed, 20 May 2020 10:22:28 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1jbPbx-00036v-RI; Wed, 20 May 2020 15:22:21 +0100 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1jbPbw-007DTN-2o; Wed, 20 May 2020 15:22:20 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Paolo Bonzini" , "Sean Christopherson" Date: Wed, 20 May 2020 15:14:29 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 61/99] KVM: x86/mmu: Apply max PA check for MMIO sptes to 32-bit KVM In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.84-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Sean Christopherson commit e30a7d623dccdb3f880fbcad980b0cb589a1da45 upstream. Remove the bogus 64-bit only condition from the check that disables MMIO spte optimization when the system supports the max PA, i.e. doesn't have any reserved PA bits. 32-bit KVM always uses PAE paging for the shadow MMU, and per Intel's SDM: PAE paging translates 32-bit linear addresses to 52-bit physical addresses. The kernel's restrictions on max physical addresses are limits on how much memory the kernel can reasonably use, not what physical addresses are supported by hardware. Fixes: ce88decffd17 ("KVM: MMU: mmio page fault support") Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini [bwh: Backported to 3.16: adjust filename, context] Signed-off-by: Ben Hutchings --- arch/x86/kvm/x86.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5734,7 +5734,7 @@ static void kvm_set_mmio_spte_mask(void) * If reserved bit is not supported, clear the present bit to disable * mmio page fault. */ - if (IS_ENABLED(CONFIG_X86_64) && maxphyaddr == 52) + if (maxphyaddr == 52) mask &= ~1ull; kvm_mmu_set_mmio_spte_mask(mask);