From patchwork Tue Aug 18 13:28:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 11720879 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B857A1392 for ; Tue, 18 Aug 2020 13:34:09 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 5244820738 for ; Tue, 18 Aug 2020 13:34:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="K4s2Ao6Z"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="UOg3as0e" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5244820738 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc: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:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=odylF4jEJcrMLdEcX90HiVSn/6ee/1xzQQvBAKlK260=; b=K4s2Ao6Z9I7sjHEaTJvNUvnvd l2+oSPIWxAN3USyyAT43d7GQfJhWBhIuImmibptaLoKWcauanw4dnlR40xHjTQ88sBmbYb+q8Ei86 RQZyTsjj3FG0V2QJUm508X7v4DEKxkRQIB7vlxzJjmEa0LTJJ4IUAwXnSNLZyBTEI9y9ZnFLHwkhc JP5lbgTJrvMWB2n/umL7ULZJBG9U3eJFo+4phRdoAFzfvOEzAva/rIMTSfKo2mTpopcGBmcMy/UW3 36uGRxqlqSkg3oNp/8qZWzSIZCeJGrlPLq6ldcj3YRma0B0yFSXisc+bQV7D0lNO9jEYize436mZG YLnJ3xeig==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k81hr-0000R3-Ei; Tue, 18 Aug 2020 13:31:15 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k81fj-0007pr-W8 for linux-arm-kernel@lists.infradead.org; Tue, 18 Aug 2020 13:29:05 +0000 Received: from localhost.localdomain (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9C7E220829; Tue, 18 Aug 2020 13:29:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597757343; bh=9WG8XylTS4DS5/FtKp5PfpoyYAMpy2KbTQsApo7FeyU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UOg3as0einoQg9LlbIPFwOMaNaQKcgx9XA4oy/+oKy4a+PDVX+xX/ShbCMFlwtIHP eZwxIQic/2qagUoOpAHdhEqo94fn351S3QC/DXgyA+OoqnzOlGDF9rSHP5J8HhbmVv QmTYLBlZ5k/NFOy8OhiNFc9FVADsDkbAihNqmuus= From: Will Deacon To: kvmarm@lists.cs.columbia.edu Subject: [PATCH v2 17/22] KVM: arm64: Add support for relaxing stage-2 perms in generic page-table code Date: Tue, 18 Aug 2020 14:28:13 +0100 Message-Id: <20200818132818.16065-18-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200818132818.16065-1-will@kernel.org> References: <20200818132818.16065-1-will@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200818_092904_181556_60963D2B X-CRM114-Status: GOOD ( 15.79 ) X-Spam-Score: -5.2 (-----) X-Spam-Report: SpamAssassin version 3.4.4 on merlin.infradead.org summary: Content analysis details: (-5.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at https://www.dnswl.org/, high trust [198.145.29.99 listed in list.dnswl.org] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.0 DKIMWL_WL_HIGH DKIMwl.org - Whitelisted High sender X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kernel-team@android.com, Suzuki Poulose , Marc Zyngier , Quentin Perret , James Morse , Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Add support for relaxing the permissions of a stage-2 mapping (i.e. adding additional permissions) to the generic page-table code. Cc: Marc Zyngier Cc: Quentin Perret Signed-off-by: Will Deacon --- arch/arm64/include/asm/kvm_pgtable.h | 17 +++++++++++++++++ arch/arm64/kvm/hyp/pgtable.c | 20 ++++++++++++++++++++ 2 files changed, 37 insertions(+) diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index ea823fe31913..0d7077c34152 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -216,6 +216,23 @@ kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr); */ kvm_pte_t kvm_pgtable_stage2_mkold(struct kvm_pgtable *pgt, u64 addr); +/** + * kvm_pgtable_stage2_relax_perms() - Relax the permissions enforced by a + * page-table entry. + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init(). + * @addr: Intermediate physical address to identify the page-table entry. + * @prot: Additional permissions to grant for the mapping. + * + * If there is a valid, leaf page-table entry used to translate @addr, then + * relax the permissions in that entry according to the read, write and + * execute permissions specified by @prot. No permissions are removed, and + * TLB invalidation is performed after updating the entry. + * + * Return: 0 on success, negative error code on failure. + */ +int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr, + enum kvm_pgtable_prot prot); + /** * kvm_pgtable_stage2_is_young() - Test whether a page-table entry has the * access flag set. diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index 75887185f1e2..6e8ca1ec12b4 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -762,6 +762,26 @@ bool kvm_pgtable_stage2_is_young(struct kvm_pgtable *pgt, u64 addr) return pte & KVM_PTE_LEAF_ATTR_LO_S2_AF; } +int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr, + enum kvm_pgtable_prot prot) +{ + int ret; + kvm_pte_t set = 0, clr = 0; + + if (prot & KVM_PGTABLE_PROT_R) + set |= KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R; + + if (prot & KVM_PGTABLE_PROT_W) + set |= KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W; + + if (prot & KVM_PGTABLE_PROT_X) + clr |= KVM_PTE_LEAF_ATTR_HI_S2_XN; + + ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL); + kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, pgt->mmu, addr, 0); + return ret; +} + static int stage2_flush_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, enum kvm_pgtable_walk_flags flag, void * const arg)