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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=gfiHymujT90+JTioTORFyQuGb6sMWBc+uaQrg+QHDRU=; b=nuoyUEV7yJW3g+cICxCJwomlY eKT7DNct1wokyL33hbumvNpN+U0qulQ8cSYn61Px6UspC+XFIJjuP3qzoSaiwJ5UicbVKFU6EX023 GR3KOIijp9tOOD9pkec6u44cSJC7GMn7saZ8L6ik6bXgfuanrZC2vqhPg2WBCq3U1TK40x39ReVQE ZRjDT6Jumq4J2N7svzIJgoRp/inHJkG2B+VVcrbPgxz6abYTQpDzb9/1KRv3nn30EXx/egVoGwmji xJOcgs+TOrfr8J33YKkOmtWkE7BiNLj9BEzIHgAHJ3A2Ikvu8/jHOOtkwsPP4WGqAMDgKrIVBF8jo h3rJFlZjA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kGj3u-0004aT-Qa; Fri, 11 Sep 2020 13:25:58 +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 1kGj3m-0004YR-1F for linux-arm-kernel@lists.infradead.org; Fri, 11 Sep 2020 13:25:51 +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 5BC7822225; Fri, 11 Sep 2020 13:25:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599830749; bh=zox+3YLRmSP3r2bD5xJoRb4ETt2hbpu9pENOsLaaG18=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bdjSd+AdCI8AhIY16QSkQq5CgIfI8vVZNHVluBrFyHnk56E3jb3QQvH8P2C+DojAz XIU3F9Al3rxVRVXUZ70PfMv0F3JlWXmsPE5pAuakZZLx5lFGvGl56C2ywvCWzRKiQW r6QH4LQJt58IIHrnLToXDrxYNR+cpFxtzMtx+te8= From: Will Deacon To: kvmarm@lists.cs.columbia.edu Subject: [PATCH v5 05/21] KVM: arm64: Add support for creating kernel-agnostic stage-2 page tables Date: Fri, 11 Sep 2020 14:25:13 +0100 Message-Id: <20200911132529.19844-6-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200911132529.19844-1-will@kernel.org> References: <20200911132529.19844-1-will@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200911_092550_275227_0AE4ECA9 X-CRM114-Status: GOOD ( 23.89 ) 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_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an 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 Message has at least one valid DKIM or DK signature -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -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, Gavin Shan , Suzuki Poulose , Marc Zyngier , Quentin Perret , Alexandru Elisei , James Morse , Andrew Scull , 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 Introduce alloc() and free() functions to the generic page-table code for guest stage-2 page-tables and plumb these into the existing KVM page-table allocator. Subsequent patches will convert other operations within the KVM allocator over to the generic code. Cc: Marc Zyngier Cc: Quentin Perret Reviewed-by: Gavin Shan Signed-off-by: Will Deacon --- arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/include/asm/kvm_pgtable.h | 18 +++++++++ arch/arm64/kvm/hyp/pgtable.c | 54 +++++++++++++++++++++++++++ arch/arm64/kvm/mmu.c | 55 +++++++++++++++------------- 4 files changed, 102 insertions(+), 26 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index e52c927aade5..0b7c702b2151 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -81,6 +81,7 @@ struct kvm_s2_mmu { */ pgd_t *pgd; phys_addr_t pgd_phys; + struct kvm_pgtable *pgt; /* The last vcpu id that ran on each physical CPU */ int __percpu *last_vcpu_ran; diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index ff5d7d27eb39..21d71395a377 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -122,6 +122,24 @@ void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt); int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys, enum kvm_pgtable_prot prot); +/** + * kvm_pgtable_stage2_init() - Initialise a guest stage-2 page-table. + * @pgt: Uninitialised page-table structure to initialise. + * @kvm: KVM structure representing the guest virtual machine. + * + * Return: 0 on success, negative error code on failure. + */ +int kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm *kvm); + +/** + * kvm_pgtable_stage2_destroy() - Destroy an unused guest stage-2 page-table. + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init(). + * + * The page-table is assumed to be unreachable by any hardware walkers prior + * to freeing and therefore no TLB invalidation is performed. + */ +void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt); + /** * kvm_pgtable_walk() - Walk a page-table. * @pgt: Page-table structure initialised by kvm_pgtable_*_init(). diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index 23a1006aa4ef..16b34d11e7cf 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -416,3 +416,57 @@ void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt) free_page((unsigned long)pgt->pgd); pgt->pgd = NULL; } + +int kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm *kvm) +{ + size_t pgd_sz; + u64 vtcr = kvm->arch.vtcr; + u32 ia_bits = VTCR_EL2_IPA(vtcr); + u32 sl0 = FIELD_GET(VTCR_EL2_SL0_MASK, vtcr); + u32 start_level = VTCR_EL2_TGRAN_SL0_BASE - sl0; + + pgd_sz = kvm_pgd_pages(ia_bits, start_level) * PAGE_SIZE; + pgt->pgd = alloc_pages_exact(pgd_sz, GFP_KERNEL | __GFP_ZERO); + if (!pgt->pgd) + return -ENOMEM; + + pgt->ia_bits = ia_bits; + pgt->start_level = start_level; + pgt->mmu = &kvm->arch.mmu; + + /* Ensure zeroed PGD pages are visible to the hardware walker */ + dsb(ishst); + return 0; +} + +static int stage2_free_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; + + if (!kvm_pte_valid(pte)) + return 0; + + put_page(virt_to_page(ptep)); + + if (kvm_pte_table(pte, level)) + free_page((unsigned long)kvm_pte_follow(pte)); + + return 0; +} + +void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt) +{ + size_t pgd_sz; + struct kvm_pgtable_walker walker = { + .cb = stage2_free_walker, + .flags = KVM_PGTABLE_WALK_LEAF | + KVM_PGTABLE_WALK_TABLE_POST, + }; + + WARN_ON(kvm_pgtable_walk(pgt, 0, BIT(pgt->ia_bits), &walker)); + pgd_sz = kvm_pgd_pages(pgt->ia_bits, pgt->start_level) * PAGE_SIZE; + free_pages_exact(pgt->pgd, pgd_sz); + pgt->pgd = NULL; +} diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index fabd72b0c8a4..4607e9ca60a2 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -668,47 +668,49 @@ int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size, * @kvm: The pointer to the KVM structure * @mmu: The pointer to the s2 MMU structure * - * Allocates only the stage-2 HW PGD level table(s) of size defined by - * stage2_pgd_size(mmu->kvm). - * + * Allocates only the stage-2 HW PGD level table(s). * Note we don't need locking here as this is only called when the VM is * created, which can only be done once. */ int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu) { - phys_addr_t pgd_phys; - pgd_t *pgd; - int cpu; + int cpu, err; + struct kvm_pgtable *pgt; - if (mmu->pgd != NULL) { + if (mmu->pgt != NULL) { kvm_err("kvm_arch already initialized?\n"); return -EINVAL; } - /* Allocate the HW PGD, making sure that each page gets its own refcount */ - pgd = alloc_pages_exact(stage2_pgd_size(kvm), GFP_KERNEL | __GFP_ZERO); - if (!pgd) + pgt = kzalloc(sizeof(*pgt), GFP_KERNEL); + if (!pgt) return -ENOMEM; - pgd_phys = virt_to_phys(pgd); - if (WARN_ON(pgd_phys & ~kvm_vttbr_baddr_mask(kvm))) - return -EINVAL; + err = kvm_pgtable_stage2_init(pgt, kvm); + if (err) + goto out_free_pgtable; mmu->last_vcpu_ran = alloc_percpu(typeof(*mmu->last_vcpu_ran)); if (!mmu->last_vcpu_ran) { - free_pages_exact(pgd, stage2_pgd_size(kvm)); - return -ENOMEM; + err = -ENOMEM; + goto out_destroy_pgtable; } for_each_possible_cpu(cpu) *per_cpu_ptr(mmu->last_vcpu_ran, cpu) = -1; mmu->kvm = kvm; - mmu->pgd = pgd; - mmu->pgd_phys = pgd_phys; + mmu->pgt = pgt; + mmu->pgd_phys = __pa(pgt->pgd); + mmu->pgd = (void *)pgt->pgd; mmu->vmid.vmid_gen = 0; - return 0; + +out_destroy_pgtable: + kvm_pgtable_stage2_destroy(pgt); +out_free_pgtable: + kfree(pgt); + return err; } static void stage2_unmap_memslot(struct kvm *kvm, @@ -781,20 +783,21 @@ void stage2_unmap_vm(struct kvm *kvm) void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu) { struct kvm *kvm = mmu->kvm; - void *pgd = NULL; + struct kvm_pgtable *pgt = NULL; spin_lock(&kvm->mmu_lock); - if (mmu->pgd) { - unmap_stage2_range(mmu, 0, kvm_phys_size(kvm)); - pgd = READ_ONCE(mmu->pgd); + pgt = mmu->pgt; + if (pgt) { mmu->pgd = NULL; + mmu->pgd_phys = 0; + mmu->pgt = NULL; + free_percpu(mmu->last_vcpu_ran); } spin_unlock(&kvm->mmu_lock); - /* Free the HW pgd, one page at a time */ - if (pgd) { - free_pages_exact(pgd, stage2_pgd_size(kvm)); - free_percpu(mmu->last_vcpu_ran); + if (pgt) { + kvm_pgtable_stage2_destroy(pgt); + kfree(pgt); } }