From patchwork Wed Aug 25 16:17:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Elisei X-Patchwork-Id: 12458243 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=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 CB668C4338F for ; Wed, 25 Aug 2021 16:22:00 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9A628610D1 for ; Wed, 25 Aug 2021 16:22:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 9A628610D1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Cc:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=T8bjTMnwh3iHmi7DLe9SpfKWQtF9MPDtgdzTzfAUj2s=; b=EaOGZN1/L0clgQ 18Jvrtantzt87ZNHebpb+mY1ewOdR3daV1J7p8dvL9QEm+dgAFinijxiDKyTB3UswKCdpzkD+fzxU GLbd4pbJVDGLKxIAnIprPXSt5qrXTRdHohNGraW6c9MWr7Rouk6WYWjvZCR7Z437EBmruLEm/P0Sr s0E3Wj/37Cup5In5O565JZPNG6MqSEnU0wv4Duk6A1Tnmc1gi1iufZ+m4mK3+RuJ1jfE3eqcovqYv ndgCyKLUFYJlNlbQ/nGmUseHUYGr09GnqGmU69lI3MxvJuy+GR8PHIigt3BiDdUAAOiIe0Z8ioMxI rB1gpdRvK5Lk3z7LX2jg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mIvdD-007hnd-Uk; Wed, 25 Aug 2021 16:20:04 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mIvaf-007gUm-Ea for linux-arm-kernel@lists.infradead.org; Wed, 25 Aug 2021 16:17:26 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0CEC8D6E; Wed, 25 Aug 2021 09:17:25 -0700 (PDT) Received: from monolith.cable.virginm.net (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B362E3F66F; Wed, 25 Aug 2021 09:17:23 -0700 (PDT) From: Alexandru Elisei To: maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, will@kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH v4 08/39] KVM: arm64: Deny changes to locked memslots Date: Wed, 25 Aug 2021 17:17:44 +0100 Message-Id: <20210825161815.266051-9-alexandru.elisei@arm.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210825161815.266051-1-alexandru.elisei@arm.com> References: <20210825161815.266051-1-alexandru.elisei@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210825_091725_580802_D07C94AF X-CRM114-Status: GOOD ( 12.81 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Forbid userspace from making changes to a locked memslot. If userspace wants to modify a locked memslot, then they will need to unlock it. One special case is allowed: memslots locked for read, but not for write, can have dirty page logging turned on. Signed-off-by: Alexandru Elisei --- arch/arm64/kvm/mmu.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 27b7befd4fa9..3ab8eba808ae 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1842,8 +1842,23 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, { hva_t hva = mem->userspace_addr; hva_t reg_end = hva + mem->memory_size; + struct kvm_memory_slot *old; int ret = 0; + /* + * Forbid all changes to locked memslots with the exception of turning + * on dirty page logging for memslots locked only for reads. + */ + old = id_to_memslot(kvm_memslots(kvm), memslot->id); + if (old && memslot_is_locked(old)) { + if (change == KVM_MR_FLAGS_ONLY && + memslot_is_logging(memslot) && + !(old->arch.flags & KVM_MEMSLOT_LOCK_WRITE)) + memcpy(&memslot->arch, &old->arch, sizeof(old->arch)); + else + return -EBUSY; + } + if (change != KVM_MR_CREATE && change != KVM_MR_MOVE && change != KVM_MR_FLAGS_ONLY) return 0;