From patchwork Wed Nov 17 15:38:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Elisei X-Patchwork-Id: 12692941 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A346C433FE for ; Wed, 17 Nov 2021 15:42:34 +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 1AEA661A07 for ; Wed, 17 Nov 2021 15:42:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 1AEA661A07 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=f8sW9YyBnAQikTekwVmGr6u+G8S07kKAzMhyaL7yNrw=; b=4DaBG76D343vEN r0CgolD5JgIsIc+ixxHtdf3i4HLhY1hSECdzvJPU3qlK8DjYdMWT9z76DtRowSROO9n+9xKjr+Yia b/ZkEidNa7K//iFpra67SqzToA2UeVQITvdLWPgc0vO3xWoZPJAkQ9otaaHiFBjutmFuPhnYcruGD qVPqNrl358+GfpANYFXcoGXCBwWicXaY9nU9XxQL4YiT1atpBKzDQ2BXDsYBkrwrELXO4BI8ZgEVi gUyM6Bhi1xlTNylLkNrocOSA3h4Go9+QR1mCJEiDEl/qYzc9USd4l/EP7VmawqPFUA+1qStlEHDv9 usmZsCd3yG1QkIyoc7Ow==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mnN3Y-005Rj8-Hg; Wed, 17 Nov 2021 15:41:04 +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 1mnMzu-005Px1-9c for linux-arm-kernel@lists.infradead.org; Wed, 17 Nov 2021 15:37:19 +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 05745ED1; Wed, 17 Nov 2021 07:37:18 -0800 (PST) Received: from monolith.localdoman (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B0D913F5A1; Wed, 17 Nov 2021 07:37:16 -0800 (PST) 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, mark.rutland@arm.com Subject: [RFC PATCH v5 09/38] KVM: arm64: Deny changes to locked memslots Date: Wed, 17 Nov 2021 15:38:13 +0000 Message-Id: <20211117153842.302159-10-alexandru.elisei@arm.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211117153842.302159-1-alexandru.elisei@arm.com> References: <20211117153842.302159-1-alexandru.elisei@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211117_073718_406118_CFC32BBE X-CRM114-Status: GOOD ( 11.83 ) 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 072e2aba371f..bc2a546f65c3 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1890,8 +1890,23 @@ 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;