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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 5B486C48BC2 for ; Mon, 21 Jun 2021 10:45:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3DA00610CA for ; Mon, 21 Jun 2021 10:45:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229661AbhFUKrc (ORCPT ); Mon, 21 Jun 2021 06:47:32 -0400 Received: from forward2-smtp.messagingengine.com ([66.111.4.226]:53281 "EHLO forward2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229641AbhFUKrb (ORCPT ); Mon, 21 Jun 2021 06:47:31 -0400 Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailforward.nyi.internal (Postfix) with ESMTP id 772C8194095D; Mon, 21 Jun 2021 06:45:15 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute3.internal (MEProxy); Mon, 21 Jun 2021 06:45:15 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=DIMItg fiEkr8jnDKVX75Zrb37gVoSGsWb2og63rjWOc=; b=fQ+U1YU8du+PphfWWQZcvO hcitbgJdDobF4o1hGO3SrGJ4dkjzywSXTE5vIlOn2qNWTsi0m7VmZsEUsSm4G7Uu Kru+sFg8WelVshB5Gw+tny0n3gjJGap2JnUYvNujHWiiEvjlgZm0Zzgr4wkwImt9 wdX8PnzeklhDAH7PC7CEJZrnTxx6Jw4i15nC4vXpEGo6fbv3EdZi7yg9MeoyIjwd 96wkyocdzyI9RBqVPluc1JHloiGO+w9QzOAt+WdtKTuHzC80GhSYgRj8C69M/3Md eaG0KzxY/tuv+HAOJ5VGE+V3LFjrR5hVvn4Ko4Ok6s4Y4X8YU66i5BXD+UX81Yrw == X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduledrfeefledgfedvucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpefuvffhfffkgggtgfesthekredttd dtlfenucfhrhhomhepoehgrhgvghhkhheslhhinhhugihfohhunhgurghtihhonhdrohhr gheqnecuggftrfgrthhtvghrnhepleejhfevleejjeettedvhfetheekgeeutdevuddtue elffelvdeuhfffjeelgeetnecuffhomhgrihhnpegsrghsvgdrughirhgvtghtnecuvehl uhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepghhrvghgsehkrh horghhrdgtohhm X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Mon, 21 Jun 2021 06:45:14 -0400 (EDT) Subject: FAILED: patch "[PATCH] KVM: x86/mmu: Calculate and check "full" mmu_role for nested" failed to apply to 5.4-stable tree To: seanjc@google.com, pbonzini@redhat.com, vkuznets@redhat.com Cc: From: Date: Mon, 21 Jun 2021 12:45:13 +0200 Message-ID: <1624272313220173@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 654430efde27248be563df9a88631204b5fe2df2 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 10 Jun 2021 15:00:26 -0700 Subject: [PATCH] KVM: x86/mmu: Calculate and check "full" mmu_role for nested MMU Calculate and check the full mmu_role when initializing the MMU context for the nested MMU, where "full" means the bits and pieces of the role that aren't handled by kvm_calc_mmu_role_common(). While the nested MMU isn't used for shadow paging, things like the number of levels in the guest's page tables are surprisingly important when walking the guest page tables. Failure to reinitialize the nested MMU context if L2's paging mode changes can result in unexpected and/or missed page faults, and likely other explosions. E.g. if an L1 vCPU is running both a 32-bit PAE L2 and a 64-bit L2, the "common" role calculation will yield the same role for both L2s. If the 64-bit L2 is run after the 32-bit PAE L2, L0 will fail to reinitialize the nested MMU context, ultimately resulting in a bad walk of L2's page tables as the MMU will still have a guest root_level of PT32E_ROOT_LEVEL. WARNING: CPU: 4 PID: 167334 at arch/x86/kvm/vmx/vmx.c:3075 ept_save_pdptrs+0x15/0xe0 [kvm_intel] Modules linked in: kvm_intel] CPU: 4 PID: 167334 Comm: CPU 3/KVM Not tainted 5.13.0-rc1-d849817d5673-reqs #185 Hardware name: ASUS Q87M-E/Q87M-E, BIOS 1102 03/03/2014 RIP: 0010:ept_save_pdptrs+0x15/0xe0 [kvm_intel] Code: <0f> 0b c3 f6 87 d8 02 00f RSP: 0018:ffffbba702dbba00 EFLAGS: 00010202 RAX: 0000000000000011 RBX: 0000000000000002 RCX: ffffffff810a2c08 RDX: ffff91d7bc30acc0 RSI: 0000000000000011 RDI: ffff91d7bc30a600 RBP: ffff91d7bc30a600 R08: 0000000000000010 R09: 0000000000000007 R10: 0000000000000000 R11: 0000000000000000 R12: ffff91d7bc30a600 R13: ffff91d7bc30acc0 R14: ffff91d67c123460 R15: 0000000115d7e005 FS: 00007fe8e9ffb700(0000) GS:ffff91d90fb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000029f15a001 CR4: 00000000001726e0 Call Trace: kvm_pdptr_read+0x3a/0x40 [kvm] paging64_walk_addr_generic+0x327/0x6a0 [kvm] paging64_gva_to_gpa_nested+0x3f/0xb0 [kvm] kvm_fetch_guest_virt+0x4c/0xb0 [kvm] __do_insn_fetch_bytes+0x11a/0x1f0 [kvm] x86_decode_insn+0x787/0x1490 [kvm] x86_decode_emulated_instruction+0x58/0x1e0 [kvm] x86_emulate_instruction+0x122/0x4f0 [kvm] vmx_handle_exit+0x120/0x660 [kvm_intel] kvm_arch_vcpu_ioctl_run+0xe25/0x1cb0 [kvm] kvm_vcpu_ioctl+0x211/0x5a0 [kvm] __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x40/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xae Cc: Vitaly Kuznetsov Cc: stable@vger.kernel.org Fixes: bf627a928837 ("x86/kvm/mmu: check if MMU reconfiguration is needed in init_kvm_nested_mmu()") Signed-off-by: Sean Christopherson Message-Id: <20210610220026.1364486-1-seanjc@google.com> Signed-off-by: Paolo Bonzini diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 0144c40d09c7..8d5876dfc6b7 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4739,9 +4739,33 @@ static void init_kvm_softmmu(struct kvm_vcpu *vcpu) context->inject_page_fault = kvm_inject_page_fault; } +static union kvm_mmu_role kvm_calc_nested_mmu_role(struct kvm_vcpu *vcpu) +{ + union kvm_mmu_role role = kvm_calc_shadow_root_page_role_common(vcpu, false); + + /* + * Nested MMUs are used only for walking L2's gva->gpa, they never have + * shadow pages of their own and so "direct" has no meaning. Set it + * to "true" to try to detect bogus usage of the nested MMU. + */ + role.base.direct = true; + + if (!is_paging(vcpu)) + role.base.level = 0; + else if (is_long_mode(vcpu)) + role.base.level = is_la57_mode(vcpu) ? PT64_ROOT_5LEVEL : + PT64_ROOT_4LEVEL; + else if (is_pae(vcpu)) + role.base.level = PT32E_ROOT_LEVEL; + else + role.base.level = PT32_ROOT_LEVEL; + + return role; +} + static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu) { - union kvm_mmu_role new_role = kvm_calc_mmu_role_common(vcpu, false); + union kvm_mmu_role new_role = kvm_calc_nested_mmu_role(vcpu); struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; if (new_role.as_u64 == g_context->mmu_role.as_u64)