From patchwork Thu Jul 30 15:33:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 11693265 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 9BF6C138C for ; Thu, 30 Jul 2020 15:35:45 +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 5298120838 for ; Thu, 30 Jul 2020 15:35:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Bf8SMl6x"; 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 5298120838 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=3Gb6xYAH9nKIJz2bLJ6d/bTSmQftkzodobSTY3sE9RM=; b=Bf8SMl6xXGlALz3Ux6wsCurd8 JeDYtsuXdBc9kLwLXO9EilyQbmsHlWVkDDjmjLiUk8YxI5DNWRmpD73p2t6FBcxRjZ4WVE3nTv9gy p7Jq+Ky3QgQ15YXqV2UVdztGUqi5vuaX9Nyk9/xGGfIApS+vKLWO9N66YMizas/9U21JcxfzBSx/Y yUCUglaGYA1ivcyus2kJ4wrImeT5PHIozLq1jR9TYgXNJA9Bvd3vgDK0tZypwwKdG+FLASVEaXwTY WERTAWo3XberQfTmPwfy1SCckDTF2R1U21jn9nNCcO0d6cHqLDkF02K55vMW9CBNvJb0sXQUJsjK0 wUlT0Yt7Q==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k1AaZ-0002CI-VI; Thu, 30 Jul 2020 15:35:24 +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 1k1AZq-0001vO-JT for linux-arm-kernel@lists.infradead.org; Thu, 30 Jul 2020 15:34:39 +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 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200730_113438_860222_BFC46F33 X-CRM114-Status: GOOD ( 20.66 ) 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_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -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 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;