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=-12.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 74F5CC433E0 for ; Thu, 30 Jul 2020 15:34:43 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 2799820838 for ; Thu, 30 Jul 2020 15:34:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="I19mpg89" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2799820838 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id D4A104B4C6; Thu, 30 Jul 2020 11:34:42 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@kernel.org Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ZPvdABW3Xf8c; Thu, 30 Jul 2020 11:34:41 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id AD3934B4CE; Thu, 30 Jul 2020 11:34:41 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id CE2A94B4CE for ; Thu, 30 Jul 2020 11:34:40 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id kYgXpqBp83ql for ; Thu, 30 Jul 2020 11:34:39 -0400 (EDT) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id B50894B163 for ; Thu, 30 Jul 2020 11:34:38 -0400 (EDT) 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 6539622B42; Thu, 30 Jul 2020 15:34:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596123278; bh=2GM58Wm9g1idig7X+ffyadAqjzM52YvyGT/Th3S3rB8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=I19mpg89CK8qe6RmLIBapp9fFu0i8o28+4BJhQfC1vUtMZI6ZD96tuexXPIvqeuXM vQYEU+cQ/NA31t5liBvLCjeNuTZx2SBl7KGlkYQqSedTMX/AugyBhnjMWVy4NmLuwB IC78DORQM5tq9u63itjkBsTO3ikLd8WUEFjty9oc= From: Will Deacon To: kvmarm@lists.cs.columbia.edu Subject: [PATCH 09/20] KVM: arm64: Add support for stage-2 page-aging in generic page-table Date: Thu, 30 Jul 2020 16:33:55 +0100 Message-Id: <20200730153406.25136-10-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200730153406.25136-1-will@kernel.org> References: <20200730153406.25136-1-will@kernel.org> MIME-Version: 1.0 Cc: kernel-team@android.com, Marc Zyngier , Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu Add stage-2 mkyoung(), mkold() and is_young() operations to the generic page-table code. Cc: Marc Zyngier Cc: Quentin Perret Signed-off-by: Will Deacon --- arch/arm64/include/asm/kvm_pgtable.h | 38 +++++++++++++ arch/arm64/kvm/pgtable.c | 85 ++++++++++++++++++++++++++++ 2 files changed, 123 insertions(+) diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index 3e0f7df89fef..7bc55e874a90 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -155,6 +155,44 @@ int kvm_pgtable_stage2_map(void *cookie, u64 addr, u64 size, u64 phys, */ int kvm_pgtable_stage2_unmap(void *cookie, u64 addr, u64 size); +/** + * kvm_pgtable_stage2_mkyoung() - Set the access flag in a page-table entry. + * @cookie: Opaque cookie allocated by kvm_pgtable_stage2_alloc_cookie(). + * @addr: Intermediate physical address to identify the page-table entry. + * + * If there is a valid, leaf page-table entry used to translate @addr, then + * set the access flag in that entry. + * + * Return: The old page-table entry prior to setting the flag, 0 on failure. + */ +kvm_pte_t kvm_pgtable_stage2_mkyoung(void *cookie, u64 addr); + +/** + * kvm_pgtable_stage2_mkold() - Clear the access flag in a page-table entry. + * @cookie: Opaque cookie allocated by kvm_pgtable_stage2_alloc_cookie(). + * @addr: Intermediate physical address to identify the page-table entry. + * + * If there is a valid, leaf page-table entry used to translate @addr, then + * clear the access flag in that entry. + * + * Note that it is the caller's responsibility to invalidate the TLB after + * calling this function to ensure that the updated permissions are visible + * to the CPUs. + * + * Return: The old page-table entry prior to clearing the flag, 0 on failure. + */ +kvm_pte_t kvm_pgtable_stage2_mkold(void *cookie, u64 addr); + +/** + * kvm_pgtable_stage2_is_young() - Test whether a page-table entry has the + * access flag set. + * @cookie: Opaque cookie allocated by kvm_pgtable_stage2_alloc_cookie(). + * @addr: Intermediate physical address to identify the page-table entry. + * + * Return: True if the page-table entry has the access flag set, false otherwise. + */ +bool kvm_pgtable_stage2_is_young(void *cookie, u64 addr); + /** * kvm_pgtable_get_pgd_phys() - Get physical pgd pointer for a page-table. * @cookie: Opaque cookie allocated by kvm_pgtable_*_alloc_cookie(). diff --git a/arch/arm64/kvm/pgtable.c b/arch/arm64/kvm/pgtable.c index 478f1a48ddc3..af15282d3df9 100644 --- a/arch/arm64/kvm/pgtable.c +++ b/arch/arm64/kvm/pgtable.c @@ -709,6 +709,91 @@ int kvm_pgtable_stage2_unmap(void *cookie, u64 addr, u64 size) return kvm_pgtable_walk(cookie, addr, size, &walker); } + +struct stage2_attr_data { + kvm_pte_t attr_set; + kvm_pte_t attr_clr; + kvm_pte_t pte; +}; + +static int stage2_attr_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, + enum kvm_pgtable_walk_flags flag, + void * const arg) +{ + kvm_pte_t pte = *ptep; + struct stage2_attr_data *data = arg; + + if (!kvm_pte_valid(pte)) + return 0; + + data->pte = pte; + pte &= ~data->attr_clr; + pte |= data->attr_set; + + /* + * We may race with the CPU trying to set the access flag here, + * but worst-case the access flag update gets lost and will be + * set on the next access instead. + */ + WRITE_ONCE(*ptep, pte); + return 0; +} + +static int stage2_update_leaf_attrs(struct kvm_pgtable *pgt, u64 addr, + u64 size, kvm_pte_t attr_set, + kvm_pte_t attr_clr, kvm_pte_t *orig_pte) +{ + int ret; + kvm_pte_t attr_mask = KVM_PTE_LEAF_ATTR_LO | KVM_PTE_LEAF_ATTR_HI; + struct stage2_attr_data data = { + .attr_set = attr_set & attr_mask, + .attr_clr = attr_clr & attr_mask, + }; + struct kvm_pgtable_walker walker = { + .cb = stage2_attr_walker, + .arg = &data, + .flags = KVM_PGTABLE_WALK_LEAF, + }; + + ret = kvm_pgtable_walk(pgt, addr, size, &walker); + if (ret) + return ret; + + if (orig_pte) + *orig_pte = data.pte; + return 0; +} + +kvm_pte_t kvm_pgtable_stage2_mkyoung(void *cookie, u64 addr) +{ + kvm_pte_t pte = 0; + stage2_update_leaf_attrs(cookie, addr, 1, KVM_PTE_LEAF_ATTR_LO_S2_AF, 0, + &pte); + dsb(ishst); + return pte; +} + +kvm_pte_t kvm_pgtable_stage2_mkold(void *cookie, u64 addr) +{ + kvm_pte_t pte = 0; + stage2_update_leaf_attrs(cookie, addr, 1, 0, KVM_PTE_LEAF_ATTR_LO_S2_AF, + &pte); + /* + * "But where's the TLBI?!", you scream. + * "Over in the core code", I sigh. + * + * See the '->clear_flush_young()' callback on the KVM mmu notifier. + */ + return pte; +} + +bool kvm_pgtable_stage2_is_young(void *cookie, u64 addr) +{ + kvm_pte_t pte = 0; + stage2_update_leaf_attrs(cookie, addr, 1, 0, 0, &pte); + return !!(pte & KVM_PTE_LEAF_ATTR_LO_S2_AF); +} + void *kvm_pgtable_stage2_alloc_cookie(struct kvm *kvm) { size_t pgd_sz; -- 2.28.0.rc0.142.g3c755180ce-goog _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm