From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yb1-f202.google.com (mail-yb1-f202.google.com [209.85.219.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 320DF36E for ; Tue, 7 Mar 2023 03:46:04 +0000 (UTC) Received: by mail-yb1-f202.google.com with SMTP id j125-20020a25d283000000b008f257b16d71so12743179ybg.15 for ; Mon, 06 Mar 2023 19:46:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1678160763; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=kZZEvh98SWD9tn0E0TdmaWcIXyV4ORxN7PNbtYHIGE8=; b=Wy5ar7FlY1cJem3SOk3mfW/K7als1Bqv/HgmrKNATViB0WDWrKwSQtn3yzECxRDBNz KEjzP0aagE292OG2LONhBe1ORH55XdY1aQXY252i+uR0PRXJrWmGDEiMMtx7yVOAO6/6 zrJ6xybaBeGr7khtvcbrdIMFlAhTg1oX3WB8/30hsUmjfNTRs4dE2nZXsL4Vx/PLF+Aj fSVLA/ZN+KCkELeif3F1u4kCLPINFXNnEwg8rAbqpZ3fFZyM9XxsAzsOhDryQfKqiD8I 3tEYoWRY80HVQf7QrNF3q9kMYKOiXLyvNkUTYkmnBZQ5iBWP679/4UUEBkA6Bmhg0MiA aDEw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678160763; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=kZZEvh98SWD9tn0E0TdmaWcIXyV4ORxN7PNbtYHIGE8=; b=jj4y8GpU0jgQX/Zrbfs844DPWqCUSNS1nhRSWRBP4yzbxsl+3IwPSfCF6iUf7fbX2s sVyIvsvqDnvNQp6h2BoJ/E9YJgtopqd9uAxPC7QmmT2owFoo3G2IFzhag1dBViatgbDt HexcCRG0gagWovE4rImnykf7kKCuRGegNTyn+g+4slHW2AyyJ9zzr/mYY1X+BKc3MLBb jM6/6/P6gvO6W7KEzotwBddTGO6a9ADXas9fM1/GtrLJOgREP08/qPBeuiM6K7iCqlXy Mam4PaWZHXeBv4s2TlmgK320LBMLanELrSm3a9M9lpW3cjB9yqQ987lkABYwa+i48BYZ FsqQ== X-Gm-Message-State: AO0yUKUdRbG1Lc9T8fp/QnSBu+Nzsn/n8OA7LvYoZ3pJqFOZFcboMDg8 WfGMFqn7rWDk7sjm2fOKSCApRsU3XOVSvw== X-Google-Smtp-Source: AK7set/TlOGbjrfZ/FRa7XeKFoZJcOZbWo37lMuVG4MBEXSWmDYNbgrw81za954EtOiRMdZrY+ihG81LzHO1Zg== X-Received: from ricarkol4.c.googlers.com ([fda3:e722:ac3:cc00:20:ed76:c0a8:1248]) (user=ricarkol job=sendgmr) by 2002:a05:6902:208:b0:ace:1ae4:9dd2 with SMTP id j8-20020a056902020800b00ace1ae49dd2mr7814870ybs.8.1678160763234; Mon, 06 Mar 2023 19:46:03 -0800 (PST) Date: Tue, 7 Mar 2023 03:45:46 +0000 In-Reply-To: <20230307034555.39733-1-ricarkol@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20230307034555.39733-1-ricarkol@google.com> X-Mailer: git-send-email 2.40.0.rc0.216.gc4246ad0f0-goog Message-ID: <20230307034555.39733-4-ricarkol@google.com> Subject: [PATCH v6 03/12] KVM: arm64: Add helper for creating unlinked stage2 subtrees From: Ricardo Koller To: pbonzini@redhat.com, maz@kernel.org, oupton@google.com, yuzenghui@huawei.com, dmatlack@google.com Cc: kvm@vger.kernel.org, kvmarm@lists.linux.dev, qperret@google.com, catalin.marinas@arm.com, andrew.jones@linux.dev, seanjc@google.com, alexandru.elisei@arm.com, suzuki.poulose@arm.com, eric.auger@redhat.com, gshan@redhat.com, reijiw@google.com, rananta@google.com, bgardon@google.com, ricarkol@gmail.com, Ricardo Koller , Shaoqin Huang Content-Type: text/plain; charset="UTF-8" Add a stage2 helper, kvm_pgtable_stage2_create_unlinked(), for creating unlinked tables (which is the opposite of kvm_pgtable_stage2_free_unlinked()). Creating an unlinked table is useful for splitting PMD and PUD blocks into subtrees of PAGE_SIZE PTEs. For example, a PUD can be split into PAGE_SIZE PTEs by first creating a fully populated tree, and then use it to replace the PUD in a single step. This will be used in a subsequent commit for eager huge-page splitting (a dirty-logging optimization). No functional change intended. This new function will be used in a subsequent commit. Signed-off-by: Ricardo Koller Reviewed-by: Shaoqin Huang --- arch/arm64/include/asm/kvm_pgtable.h | 28 +++++++++++++++++ arch/arm64/kvm/hyp/pgtable.c | 46 ++++++++++++++++++++++++++++ 2 files changed, 74 insertions(+) diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index c7a269cad053..b7b3fc0fa7a5 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -468,6 +468,34 @@ void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt); */ void kvm_pgtable_stage2_free_unlinked(struct kvm_pgtable_mm_ops *mm_ops, void *pgtable, u32 level); +/** + * kvm_pgtable_stage2_create_unlinked() - Create an unlinked stage-2 paging structure. + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). + * @phys: Physical address of the memory to map. + * @level: Starting level of the stage-2 paging structure to be created. + * @prot: Permissions and attributes for the mapping. + * @mc: Cache of pre-allocated and zeroed memory from which to allocate + * page-table pages. + * @force_pte: Force mappings to PAGE_SIZE granularity. + * + * Returns an unlinked page-table tree. If @force_pte is true or + * @level is 2 (the PMD level), then the tree is mapped up to the + * PAGE_SIZE leaf PTE; the tree is mapped up one level otherwise. + * This new page-table tree is not reachable (i.e., it is unlinked) + * from the root pgd and it's therefore unreachableby the hardware + * page-table walker. No TLB invalidation or CMOs are performed. + * + * If device attributes are not explicitly requested in @prot, then the + * mapping will be normal, cacheable. + * + * Return: The fully populated (unlinked) stage-2 paging structure, or + * an ERR_PTR(error) on failure. + */ +kvm_pte_t *kvm_pgtable_stage2_create_unlinked(struct kvm_pgtable *pgt, + u64 phys, u32 level, + enum kvm_pgtable_prot prot, + void *mc, bool force_pte); + /** * kvm_pgtable_stage2_map() - Install a mapping in a guest stage-2 page-table. * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index 4f703cc4cb03..6bdfcb671b32 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -1212,6 +1212,52 @@ int kvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size) return kvm_pgtable_walk(pgt, addr, size, &walker); } +kvm_pte_t *kvm_pgtable_stage2_create_unlinked(struct kvm_pgtable *pgt, + u64 phys, u32 level, + enum kvm_pgtable_prot prot, + void *mc, bool force_pte) +{ + struct stage2_map_data map_data = { + .phys = phys, + .mmu = pgt->mmu, + .memcache = mc, + .force_pte = force_pte, + }; + struct kvm_pgtable_walker walker = { + .cb = stage2_map_walker, + .flags = KVM_PGTABLE_WALK_LEAF | + KVM_PGTABLE_WALK_SKIP_BBM | + KVM_PGTABLE_WALK_SKIP_CMO, + .arg = &map_data, + }; + /* .addr (the IPA) is irrelevant for an unlinked table */ + struct kvm_pgtable_walk_data data = { + .walker = &walker, + .addr = 0, + .end = kvm_granule_size(level), + }; + struct kvm_pgtable_mm_ops *mm_ops = pgt->mm_ops; + kvm_pte_t *pgtable; + int ret; + + ret = stage2_set_prot_attr(pgt, prot, &map_data.attr); + if (ret) + return ERR_PTR(ret); + + pgtable = mm_ops->zalloc_page(mc); + if (!pgtable) + return ERR_PTR(-ENOMEM); + + ret = __kvm_pgtable_walk(&data, mm_ops, (kvm_pteref_t)pgtable, + level + 1); + if (ret) { + kvm_pgtable_stage2_free_unlinked(mm_ops, pgtable, level); + mm_ops->put_page(pgtable); + return ERR_PTR(ret); + } + + return pgtable; +} int __kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu, struct kvm_pgtable_mm_ops *mm_ops, -- 2.40.0.rc0.216.gc4246ad0f0-goog