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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 6CB72C433E9 for ; Tue, 2 Feb 2021 13:51:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 240A964FAA for ; Tue, 2 Feb 2021 13:51:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233118AbhBBNvm (ORCPT ); Tue, 2 Feb 2021 08:51:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:41120 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232944AbhBBNuC (ORCPT ); Tue, 2 Feb 2021 08:50:02 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id E8D3C64FAA; Tue, 2 Feb 2021 13:42:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612273359; bh=gUgc0r8bk0KNca2XaqGTfkET84c0c5MGJDlemNb8X/Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nFu0dvun52MZRdSsuWom1+pTXDgaR0TJbTcodczDbeVuEoY8q5x50sUmkbhPS9ogX eJJ62K0V8TLXU0/NlGAPgsm+hHR2Sbvx6A398OM27zCDsKOxMQxO8HmHzVxWp012hD t7ZNRUDnrGO0touxTinYOTxSc/zVr4fl4uehrf5U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Rick Edgecombe , Catalin Marinas , Marc Zyngier Subject: [PATCH 5.10 046/142] KVM: Forbid the use of tagged userspace addresses for memslots Date: Tue, 2 Feb 2021 14:36:49 +0100 Message-Id: <20210202132959.627719612@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210202132957.692094111@linuxfoundation.org> References: <20210202132957.692094111@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Marc Zyngier commit 139bc8a6146d92822c866cf2fd410159c56b3648 upstream. The use of a tagged address could be pretty confusing for the whole memslot infrastructure as well as the MMU notifiers. Forbid it altogether, as it never quite worked the first place. Cc: stable@vger.kernel.org Reported-by: Rick Edgecombe Reviewed-by: Catalin Marinas Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman --- Documentation/virt/kvm/api.rst | 3 +++ virt/kvm/kvm_main.c | 1 + 2 files changed, 4 insertions(+) --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -1264,6 +1264,9 @@ field userspace_addr, which must point a the entire memory slot size. Any object may back this memory, including anonymous memory, ordinary files, and hugetlbfs. +On architectures that support a form of address tagging, userspace_addr must +be an untagged address. + It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr be identical. This allows large pages in the guest to be backed by large pages in the host. --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1289,6 +1289,7 @@ int __kvm_set_memory_region(struct kvm * return -EINVAL; /* We can read the guest memory with __xxx_user() later on. */ if ((mem->userspace_addr & (PAGE_SIZE - 1)) || + (mem->userspace_addr != untagged_addr(mem->userspace_addr)) || !access_ok((void __user *)(unsigned long)mem->userspace_addr, mem->memory_size)) return -EINVAL;