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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 31970C10F14 for ; Thu, 3 Oct 2019 16:48:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 097A920865 for ; Thu, 3 Oct 2019 16:48:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570121314; bh=GWfO61UdfkXShokBTmb/zORTeBkGVGwIc2HMawHQahk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hLBG6bZnJGOng9kNoh7SNCu7Woeb2eOgH6dvHVTfbHqmFAeuAWhZwk/bUZJoBaGpw 5GHJj8j7IKUZe0kCWl2wsC8p79UhpFngyROlHDIVu4jfvbZQDBagmJuaefKaDeteVZ c+f6enxyapjTxmt+mbPJAITTXnEI0nrMTUsIj8gE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405699AbfJCQsc (ORCPT ); Thu, 3 Oct 2019 12:48:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:34282 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405669AbfJCQs3 (ORCPT ); Thu, 3 Oct 2019 12:48:29 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6D6D32070B; Thu, 3 Oct 2019 16:48:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570121307; bh=GWfO61UdfkXShokBTmb/zORTeBkGVGwIc2HMawHQahk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nOFES9rmgi8WCbE9jbP390X0kQAz2KzeSl0sGin3HjdyNJ8OIBpMX4bTTJQjxk6Un 038sC/0M6pfCbgKfom73PzG8fRIRQXJMpu20tvgMcMdY8JeXgKs5LMtBZdXel5gtgG 65OoBvVlIKokHrDirVDE1KvKTyvGAGhHU28WdrmM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jiri Palecek , Paolo Bonzini , Sasha Levin Subject: [PATCH 5.3 232/344] kvm: Nested KVM MMUs need PAE root too Date: Thu, 3 Oct 2019 17:53:17 +0200 Message-Id: <20191003154603.282028034@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191003154540.062170222@linuxfoundation.org> References: <20191003154540.062170222@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jiří Paleček [ Upstream commit 1cfff4d9a5d01fa61e5768a6afffc81ae1c8ecb9 ] On AMD processors, in PAE 32bit mode, nested KVM instances don't work. The L0 host get a kernel OOPS, which is related to arch.mmu->pae_root being NULL. The reason for this is that when setting up nested KVM instance, arch.mmu is set to &arch.guest_mmu (while normally, it would be &arch.root_mmu). However, the initialization and allocation of pae_root only creates it in root_mmu. KVM code (ie. in mmu_alloc_shadow_roots) then accesses arch.mmu->pae_root, which is the unallocated arch.guest_mmu->pae_root. This fix just allocates (and frees) pae_root in both guest_mmu and root_mmu (and also lm_root if it was allocated). The allocation is subject to previous restrictions ie. it won't allocate anything on 64-bit and AFAIK not on Intel. Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=203923 Fixes: 14c07ad89f4d ("x86/kvm/mmu: introduce guest_mmu") Signed-off-by: Jiri Palecek Tested-by: Jiri Palecek Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- arch/x86/kvm/mmu.c | 30 ++++++++++++++++++++++-------- 1 file changed, 22 insertions(+), 8 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index a63964e7cec7b..c68bf3aab12c1 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -5611,13 +5611,13 @@ slot_handle_leaf(struct kvm *kvm, struct kvm_memory_slot *memslot, PT_PAGE_TABLE_LEVEL, lock_flush_tlb); } -static void free_mmu_pages(struct kvm_vcpu *vcpu) +static void free_mmu_pages(struct kvm_mmu *mmu) { - free_page((unsigned long)vcpu->arch.mmu->pae_root); - free_page((unsigned long)vcpu->arch.mmu->lm_root); + free_page((unsigned long)mmu->pae_root); + free_page((unsigned long)mmu->lm_root); } -static int alloc_mmu_pages(struct kvm_vcpu *vcpu) +static int alloc_mmu_pages(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) { struct page *page; int i; @@ -5638,9 +5638,9 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu) if (!page) return -ENOMEM; - vcpu->arch.mmu->pae_root = page_address(page); + mmu->pae_root = page_address(page); for (i = 0; i < 4; ++i) - vcpu->arch.mmu->pae_root[i] = INVALID_PAGE; + mmu->pae_root[i] = INVALID_PAGE; return 0; } @@ -5648,6 +5648,7 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu) int kvm_mmu_create(struct kvm_vcpu *vcpu) { uint i; + int ret; vcpu->arch.mmu = &vcpu->arch.root_mmu; vcpu->arch.walk_mmu = &vcpu->arch.root_mmu; @@ -5665,7 +5666,19 @@ int kvm_mmu_create(struct kvm_vcpu *vcpu) vcpu->arch.guest_mmu.prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID; vcpu->arch.nested_mmu.translate_gpa = translate_nested_gpa; - return alloc_mmu_pages(vcpu); + + ret = alloc_mmu_pages(vcpu, &vcpu->arch.guest_mmu); + if (ret) + return ret; + + ret = alloc_mmu_pages(vcpu, &vcpu->arch.root_mmu); + if (ret) + goto fail_allocate_root; + + return ret; + fail_allocate_root: + free_mmu_pages(&vcpu->arch.guest_mmu); + return ret; } @@ -6168,7 +6181,8 @@ unsigned long kvm_mmu_calculate_default_mmu_pages(struct kvm *kvm) void kvm_mmu_destroy(struct kvm_vcpu *vcpu) { kvm_mmu_unload(vcpu); - free_mmu_pages(vcpu); + free_mmu_pages(&vcpu->arch.root_mmu); + free_mmu_pages(&vcpu->arch.guest_mmu); mmu_free_memory_caches(vcpu); } -- 2.20.1