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=-12.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 F36FCC2D0A7 for ; Tue, 8 Sep 2020 16:37:43 +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 AB87E206DB for ; Tue, 8 Sep 2020 16:37:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="bcsE6VTe" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AB87E206DB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.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:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=OxzRahZkQp1x+2+3mWnL65KBAUMvrdUlafJDEIakOd0=; b=bcsE6VTek/tVDJaoPp7h2Twy1 4c+FKeoZh17MSkqQ+rgDqGi3UNf1fDa9wXffdIhX+p7gTgZgJwfZVoapSYovv3d5L2M0iH6oIUi3Q 5UPXPNvytSE8Ltfe+7Ctiy3fuEDclFuaVxAh7I7YRL95J+n9Sb3HsZ/OPok+2JvVX/F4unKT9s6Ne /56YYG7FBhi5nCXXZkL9CzVbq1VvH2sR4YXTP+PycYWk418X4kQUIrhleXsVMbYr58wkjCTjTNEHE XgDjmltAW4trtgnToCjFFdxwZnEuwb052/30mBbBGIV89tyRDVIQRf6O+HsU1q8w8RXF3CZeCELbE QWTg3UZaA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kFgba-0006j2-Cg; Tue, 08 Sep 2020 16:36:26 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kFgbY-0006id-6m for linux-arm-kernel@lists.infradead.org; Tue, 08 Sep 2020 16:36:25 +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 06F9D31B; Tue, 8 Sep 2020 09:36:22 -0700 (PDT) Received: from [192.168.0.110] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BBB243F68F; Tue, 8 Sep 2020 09:36:20 -0700 (PDT) Subject: Re: [PATCH v4 16/21] KVM: arm64: Add support for relaxing stage-2 perms in generic page-table code To: Will Deacon , kvmarm@lists.cs.columbia.edu References: <20200907152344.12978-1-will@kernel.org> <20200907152344.12978-17-will@kernel.org> From: Alexandru Elisei Message-ID: <8f4ac895-361a-77f0-e68d-fc3b62cab385@arm.com> Date: Tue, 8 Sep 2020 17:37:08 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20200907152344.12978-17-will@kernel.org> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200908_123624_332754_B4C78F87 X-CRM114-Status: GOOD ( 22.66 ) 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: Gavin Shan , Suzuki Poulose , Marc Zyngier , Quentin Perret , James Morse , Catalin Marinas , kernel-team@android.com, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Will, Minor nitpick below. On 9/7/20 4:23 PM, Will Deacon wrote: > 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 > Reviewed-by: Gavin Shan > 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 a776bcf74316..5ab4f852a463 100644 > --- a/arch/arm64/include/asm/kvm_pgtable.h > +++ b/arch/arm64/include/asm/kvm_pgtable.h > @@ -218,6 +218,23 @@ 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 ad18ce469041..df705533dc3f 100644 > --- a/arch/arm64/kvm/hyp/pgtable.c > +++ b/arch/arm64/kvm/hyp/pgtable.c > @@ -782,6 +782,26 @@ 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); The level 0 argument could be replaced by S2_NO_LEVEL_HINT, which is self explanatory. However, that means the file needs to include stage2_pgtable.h. Thanks, Alex > + 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) _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel