From patchwork Mon Oct 17 11:52:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 13008682 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 10A56C4321E for ; Mon, 17 Oct 2022 11:53:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230298AbiJQLxu (ORCPT ); Mon, 17 Oct 2022 07:53:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33026 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230387AbiJQLxj (ORCPT ); Mon, 17 Oct 2022 07:53:39 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D784C53D39 for ; Mon, 17 Oct 2022 04:53:31 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 394ED6104D for ; Mon, 17 Oct 2022 11:53:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9CFA8C43470; Mon, 17 Oct 2022 11:53:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666007609; bh=T6Dlfxy8O91K1JKpLz6sE+xW8rmJQg8AX8DmdyH/bmM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HFZSmLBTIzDFrQCIsjVoVF/2Zb0nUvR4aBSqK72+1FgH58TGW+TMjtP7Xy/+9TliZ haISRuchdcwFixDQQusp3b4Pb+eFPwqXUhr2bTBYBoiebGOzi8eOTOxYTzG1yn33O+ llZPVM8K/Km/sM1V/8v7j2nO4qfH9yTkvqzEeBSLPLhH1Qhyrqr7v166baxjfC5Lko xhbTa1rRAi2Xm3YXJRGqKcQ7nYCN6xJAkEeY0f3O12a7Afbz4xXJuG+0qLtFQFR/F1 6dqoNJTlRhFCzmhrUuKLPYXP2n984QxmSF14TLgYrrxY6GiguN5BPwOzaeY1FUP5l/ fNIOcCHb0XyRQ== From: Will Deacon To: kvmarm@lists.linux.dev Cc: Will Deacon , Sean Christopherson , Vincent Donnefort , Alexandru Elisei , Catalin Marinas , James Morse , Chao Peng , Quentin Perret , Suzuki K Poulose , Mark Rutland , Fuad Tabba , Oliver Upton , Marc Zyngier , kernel-team@android.com, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v4 19/25] KVM: arm64: Instantiate guest stage-2 page-tables at EL2 Date: Mon, 17 Oct 2022 12:52:03 +0100 Message-Id: <20221017115209.2099-20-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20221017115209.2099-1-will@kernel.org> References: <20221017115209.2099-1-will@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Quentin Perret Extend the initialisation of guest data structures within the pKVM hypervisor at EL2 so that we instantiate a memory pool and a full 'struct kvm_s2_mmu' structure for each VM, with a stage-2 page-table entirely independent from the one managed by the host at EL1. The 'struct kvm_pgtable_mm_ops' used by the page-table code is populated with a set of callbacks that can manage guest pages in the hypervisor without any direct intervention from the host, allocating page-table pages from the provided pool and returning these to the host on VM teardown. To keep things simple, the stage-2 MMU for the guest is configured identically to the host stage-2 in the VTCR register and so the IPA size of the guest must match the PA size of the host. For now, the new page-table is unused as there is no way for the host to map anything into it. Yet. Tested-by: Vincent Donnefort Signed-off-by: Quentin Perret Signed-off-by: Will Deacon --- arch/arm64/kvm/hyp/include/nvhe/pkvm.h | 6 ++ arch/arm64/kvm/hyp/nvhe/mem_protect.c | 125 ++++++++++++++++++++++++- arch/arm64/kvm/mmu.c | 4 +- 3 files changed, 132 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/hyp/include/nvhe/pkvm.h b/arch/arm64/kvm/hyp/include/nvhe/pkvm.h index d176399dbfb5..5d456438445c 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/pkvm.h +++ b/arch/arm64/kvm/hyp/include/nvhe/pkvm.h @@ -9,6 +9,9 @@ #include +#include +#include + /* * Holds the relevant data for maintaining the vcpu state completely at hyp. */ @@ -36,6 +39,9 @@ struct pkvm_hyp_vm { /* The guest's stage-2 page-table managed by the hypervisor. */ struct kvm_pgtable pgt; + struct kvm_pgtable_mm_ops mm_ops; + struct hyp_pool pool; + hyp_spinlock_t lock; /* * The number of vcpus initialized and ready to run. diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index 1c38451050e5..27b16a6b85bb 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -25,6 +25,21 @@ struct host_mmu host_mmu; static struct hyp_pool host_s2_pool; +static DEFINE_PER_CPU(struct pkvm_hyp_vm *, __current_vm); +#define current_vm (*this_cpu_ptr(&__current_vm)) + +static void guest_lock_component(struct pkvm_hyp_vm *vm) +{ + hyp_spin_lock(&vm->lock); + current_vm = vm; +} + +static void guest_unlock_component(struct pkvm_hyp_vm *vm) +{ + current_vm = NULL; + hyp_spin_unlock(&vm->lock); +} + static void host_lock_component(void) { hyp_spin_lock(&host_mmu.lock); @@ -140,18 +155,124 @@ int kvm_host_prepare_stage2(void *pgt_pool_base) return 0; } +static bool guest_stage2_force_pte_cb(u64 addr, u64 end, + enum kvm_pgtable_prot prot) +{ + return true; +} + +static void *guest_s2_zalloc_pages_exact(size_t size) +{ + void *addr = hyp_alloc_pages(¤t_vm->pool, get_order(size)); + + WARN_ON(size != (PAGE_SIZE << get_order(size))); + hyp_split_page(hyp_virt_to_page(addr)); + + return addr; +} + +static void guest_s2_free_pages_exact(void *addr, unsigned long size) +{ + u8 order = get_order(size); + unsigned int i; + + for (i = 0; i < (1 << order); i++) + hyp_put_page(¤t_vm->pool, addr + (i * PAGE_SIZE)); +} + +static void *guest_s2_zalloc_page(void *mc) +{ + struct hyp_page *p; + void *addr; + + addr = hyp_alloc_pages(¤t_vm->pool, 0); + if (addr) + return addr; + + addr = pop_hyp_memcache(mc, hyp_phys_to_virt); + if (!addr) + return addr; + + memset(addr, 0, PAGE_SIZE); + p = hyp_virt_to_page(addr); + memset(p, 0, sizeof(*p)); + p->refcount = 1; + + return addr; +} + +static void guest_s2_get_page(void *addr) +{ + hyp_get_page(¤t_vm->pool, addr); +} + +static void guest_s2_put_page(void *addr) +{ + hyp_put_page(¤t_vm->pool, addr); +} + +static void clean_dcache_guest_page(void *va, size_t size) +{ + __clean_dcache_guest_page(hyp_fixmap_map(__hyp_pa(va)), size); + hyp_fixmap_unmap(); +} + +static void invalidate_icache_guest_page(void *va, size_t size) +{ + __invalidate_icache_guest_page(hyp_fixmap_map(__hyp_pa(va)), size); + hyp_fixmap_unmap(); +} + int kvm_guest_prepare_stage2(struct pkvm_hyp_vm *vm, void *pgd) { - vm->pgt.pgd = pgd; + struct kvm_s2_mmu *mmu = &vm->kvm.arch.mmu; + unsigned long nr_pages; + int ret; + + nr_pages = kvm_pgtable_stage2_pgd_size(vm->kvm.arch.vtcr) >> PAGE_SHIFT; + ret = hyp_pool_init(&vm->pool, hyp_virt_to_pfn(pgd), nr_pages, 0); + if (ret) + return ret; + + hyp_spin_lock_init(&vm->lock); + vm->mm_ops = (struct kvm_pgtable_mm_ops) { + .zalloc_pages_exact = guest_s2_zalloc_pages_exact, + .free_pages_exact = guest_s2_free_pages_exact, + .zalloc_page = guest_s2_zalloc_page, + .phys_to_virt = hyp_phys_to_virt, + .virt_to_phys = hyp_virt_to_phys, + .page_count = hyp_page_count, + .get_page = guest_s2_get_page, + .put_page = guest_s2_put_page, + .dcache_clean_inval_poc = clean_dcache_guest_page, + .icache_inval_pou = invalidate_icache_guest_page, + }; + + guest_lock_component(vm); + ret = __kvm_pgtable_stage2_init(mmu->pgt, mmu, &vm->mm_ops, 0, + guest_stage2_force_pte_cb); + guest_unlock_component(vm); + if (ret) + return ret; + + vm->kvm.arch.mmu.pgd_phys = __hyp_pa(vm->pgt.pgd); + return 0; } void reclaim_guest_pages(struct pkvm_hyp_vm *vm) { + void *pgd = vm->pgt.pgd; unsigned long nr_pages; nr_pages = kvm_pgtable_stage2_pgd_size(vm->kvm.arch.vtcr) >> PAGE_SHIFT; - WARN_ON(__pkvm_hyp_donate_host(hyp_virt_to_pfn(vm->pgt.pgd), nr_pages)); + + guest_lock_component(vm); + kvm_pgtable_stage2_destroy(&vm->pgt); + vm->kvm.arch.mmu.pgd_phys = 0ULL; + guest_unlock_component(vm); + + WARN_ON(__pkvm_hyp_donate_host(hyp_virt_to_pfn(pgd), nr_pages)); } int __pkvm_prot_finalize(void) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 43761d31f763..301fc7275062 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -686,7 +686,9 @@ int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long t return -EINVAL; phys_shift = KVM_VM_TYPE_ARM_IPA_SIZE(type); - if (phys_shift) { + if (is_protected_kvm_enabled()) { + phys_shift = kvm_ipa_limit; + } else if (phys_shift) { if (phys_shift > kvm_ipa_limit || phys_shift < ARM64_MIN_PARANGE_BITS) return -EINVAL;