From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 77B64259C; Fri, 27 Jan 2023 11:30:24 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 185F61576; Fri, 27 Jan 2023 03:31:06 -0800 (PST) Received: from e122027.cambridge.arm.com (e122027.cambridge.arm.com [10.1.35.16]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DE4E13F64C; Fri, 27 Jan 2023 03:30:21 -0800 (PST) From: Steven Price To: kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Steven Price , Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Suzuki K Poulose , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev Subject: [RFC PATCH 16/28] arm64: RME: Allow populating initial contents Date: Fri, 27 Jan 2023 11:29:20 +0000 Message-Id: <20230127112932.38045-17-steven.price@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230127112932.38045-1-steven.price@arm.com> References: <20230127112248.136810-1-suzuki.poulose@arm.com> <20230127112932.38045-1-steven.price@arm.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The VMM needs to populate the realm with some data before starting (e.g. a kernel and initrd). This is measured by the RMM and used as part of the attestation later on. Signed-off-by: Steven Price --- arch/arm64/kvm/rme.c | 366 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 366 insertions(+) diff --git a/arch/arm64/kvm/rme.c b/arch/arm64/kvm/rme.c index 16e0bfea98b1..3405b43e1421 100644 --- a/arch/arm64/kvm/rme.c +++ b/arch/arm64/kvm/rme.c @@ -4,6 +4,7 @@ */ #include +#include #include #include @@ -426,6 +427,359 @@ void kvm_realm_unmap_range(struct kvm *kvm, unsigned long ipa, u64 size) } } +static int realm_create_protected_data_page(struct realm *realm, + unsigned long ipa, + struct page *dst_page, + struct page *tmp_page) +{ + phys_addr_t dst_phys, tmp_phys; + int ret; + + copy_page(page_address(tmp_page), page_address(dst_page)); + + dst_phys = page_to_phys(dst_page); + tmp_phys = page_to_phys(tmp_page); + + if (rmi_granule_delegate(dst_phys)) + return -ENXIO; + + ret = rmi_data_create(dst_phys, virt_to_phys(realm->rd), ipa, tmp_phys, + RMI_MEASURE_CONTENT); + + if (RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT) { + /* Create missing RTTs and retry */ + int level = RMI_RETURN_INDEX(ret); + + ret = realm_create_rtt_levels(realm, ipa, level, + RME_RTT_MAX_LEVEL, NULL); + if (ret) + goto err; + + ret = rmi_data_create(dst_phys, virt_to_phys(realm->rd), ipa, + tmp_phys, RMI_MEASURE_CONTENT); + } + + if (ret) + goto err; + + return 0; + +err: + if (WARN_ON(rmi_granule_undelegate(dst_phys))) { + /* Page can't be returned to NS world so is lost */ + get_page(dst_page); + } + return -ENXIO; +} + +static int fold_rtt(phys_addr_t rd, unsigned long addr, int level, + struct realm *realm) +{ + struct rtt_entry rtt; + phys_addr_t rtt_addr; + + if (rmi_rtt_read_entry(rd, addr, level, &rtt)) + return -ENXIO; + + if (rtt.state != RMI_TABLE) + return -EINVAL; + + rtt_addr = rmi_rtt_get_phys(&rtt); + if (rmi_rtt_fold(rtt_addr, rd, addr, level + 1)) + return -ENXIO; + + free_delegated_page(realm, rtt_addr); + + return 0; +} + +int realm_map_protected(struct realm *realm, + unsigned long hva, + unsigned long base_ipa, + struct page *dst_page, + unsigned long map_size, + struct kvm_mmu_memory_cache *memcache) +{ + phys_addr_t dst_phys = page_to_phys(dst_page); + phys_addr_t rd = virt_to_phys(realm->rd); + unsigned long phys = dst_phys; + unsigned long ipa = base_ipa; + unsigned long size; + int map_level; + int ret = 0; + + if (WARN_ON(!IS_ALIGNED(ipa, map_size))) + return -EINVAL; + + switch (map_size) { + case PAGE_SIZE: + map_level = 3; + break; + case RME_L2_BLOCK_SIZE: + map_level = 2; + break; + default: + return -EINVAL; + } + + if (map_level < RME_RTT_MAX_LEVEL) { + /* + * A temporary RTT is needed during the map, precreate it, + * however if there is an error (e.g. missing parent tables) + * this will be handled below. + */ + realm_create_rtt_levels(realm, ipa, map_level, + RME_RTT_MAX_LEVEL, memcache); + } + + for (size = 0; size < map_size; size += PAGE_SIZE) { + if (rmi_granule_delegate(phys)) { + struct rtt_entry rtt; + + /* + * It's possible we raced with another VCPU on the same + * fault. If the entry exists and matches then exit + * early and assume the other VCPU will handle the + * mapping. + */ + if (rmi_rtt_read_entry(rd, ipa, RME_RTT_MAX_LEVEL, &rtt)) + goto err; + + // FIXME: For a block mapping this could race at level + // 2 or 3... + if (WARN_ON((rtt.walk_level != RME_RTT_MAX_LEVEL || + rtt.state != RMI_ASSIGNED || + rtt.desc != phys))) { + goto err; + } + + return 0; + } + + ret = rmi_data_create_unknown(phys, rd, ipa); + + if (RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT) { + /* Create missing RTTs and retry */ + int level = RMI_RETURN_INDEX(ret); + + ret = realm_create_rtt_levels(realm, ipa, level, + RME_RTT_MAX_LEVEL, + memcache); + WARN_ON(ret); + if (ret) + goto err_undelegate; + + ret = rmi_data_create_unknown(phys, rd, ipa); + } + WARN_ON(ret); + + if (ret) + goto err_undelegate; + + phys += PAGE_SIZE; + ipa += PAGE_SIZE; + } + + if (map_size == RME_L2_BLOCK_SIZE) + ret = fold_rtt(rd, base_ipa, map_level, realm); + if (WARN_ON(ret)) + goto err; + + return 0; + +err_undelegate: + if (WARN_ON(rmi_granule_undelegate(phys))) { + /* Page can't be returned to NS world so is lost */ + get_page(phys_to_page(phys)); + } +err: + while (size > 0) { + phys -= PAGE_SIZE; + size -= PAGE_SIZE; + ipa -= PAGE_SIZE; + + rmi_data_destroy(rd, ipa); + + if (WARN_ON(rmi_granule_undelegate(phys))) { + /* Page can't be returned to NS world so is lost */ + get_page(phys_to_page(phys)); + } + } + return -ENXIO; +} + +static int populate_par_region(struct kvm *kvm, + phys_addr_t ipa_base, + phys_addr_t ipa_end) +{ + struct realm *realm = &kvm->arch.realm; + struct kvm_memory_slot *memslot; + gfn_t base_gfn, end_gfn; + int idx; + phys_addr_t ipa; + int ret = 0; + struct page *tmp_page; + phys_addr_t rd = virt_to_phys(realm->rd); + + base_gfn = gpa_to_gfn(ipa_base); + end_gfn = gpa_to_gfn(ipa_end); + + idx = srcu_read_lock(&kvm->srcu); + memslot = gfn_to_memslot(kvm, base_gfn); + if (!memslot) { + ret = -EFAULT; + goto out; + } + + /* We require the region to be contained within a single memslot */ + if (memslot->base_gfn + memslot->npages < end_gfn) { + ret = -EINVAL; + goto out; + } + + tmp_page = alloc_page(GFP_KERNEL); + if (!tmp_page) { + ret = -ENOMEM; + goto out; + } + + mmap_read_lock(current->mm); + + ipa = ipa_base; + + while (ipa < ipa_end) { + struct vm_area_struct *vma; + unsigned long map_size; + unsigned int vma_shift; + unsigned long offset; + unsigned long hva; + struct page *page; + kvm_pfn_t pfn; + int level; + + hva = gfn_to_hva_memslot(memslot, gpa_to_gfn(ipa)); + vma = vma_lookup(current->mm, hva); + if (!vma) { + ret = -EFAULT; + break; + } + + if (is_vm_hugetlb_page(vma)) + vma_shift = huge_page_shift(hstate_vma(vma)); + else + vma_shift = PAGE_SHIFT; + + map_size = 1 << vma_shift; + + /* + * FIXME: This causes over mapping, but there's no good + * solution here with the ABI as it stands + */ + ipa = ALIGN_DOWN(ipa, map_size); + + switch (map_size) { + case RME_L2_BLOCK_SIZE: + level = 2; + break; + case PAGE_SIZE: + level = 3; + break; + default: + WARN_ONCE(1, "Unsupport vma_shift %d", vma_shift); + ret = -EFAULT; + break; + } + + pfn = gfn_to_pfn_memslot(memslot, gpa_to_gfn(ipa)); + + if (is_error_pfn(pfn)) { + ret = -EFAULT; + break; + } + + ret = rmi_rtt_init_ripas(rd, ipa, level); + if (RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT) { + ret = realm_create_rtt_levels(realm, ipa, + RMI_RETURN_INDEX(ret), + level, NULL); + if (ret) + break; + ret = rmi_rtt_init_ripas(rd, ipa, level); + if (ret) { + ret = -ENXIO; + break; + } + } + + if (level < RME_RTT_MAX_LEVEL) { + /* + * A temporary RTT is needed during the map, precreate + * it, however if there is an error (e.g. missing + * parent tables) this will be handled in the + * realm_create_protected_data_page() call. + */ + realm_create_rtt_levels(realm, ipa, level, + RME_RTT_MAX_LEVEL, NULL); + } + + page = pfn_to_page(pfn); + + for (offset = 0; offset < map_size && !ret; + offset += PAGE_SIZE, page++) { + phys_addr_t page_ipa = ipa + offset; + + ret = realm_create_protected_data_page(realm, page_ipa, + page, tmp_page); + } + if (ret) + goto err_release_pfn; + + if (level == 2) { + ret = fold_rtt(rd, ipa, level, realm); + if (ret) + goto err_release_pfn; + } + + ipa += map_size; + kvm_set_pfn_accessed(pfn); + kvm_set_pfn_dirty(pfn); + kvm_release_pfn_dirty(pfn); +err_release_pfn: + if (ret) { + kvm_release_pfn_clean(pfn); + break; + } + } + + mmap_read_unlock(current->mm); + __free_page(tmp_page); + +out: + srcu_read_unlock(&kvm->srcu, idx); + return ret; +} + +static int kvm_populate_realm(struct kvm *kvm, + struct kvm_cap_arm_rme_populate_realm_args *args) +{ + phys_addr_t ipa_base, ipa_end; + + if (kvm_realm_state(kvm) != REALM_STATE_NEW) + return -EBUSY; + + if (!IS_ALIGNED(args->populate_ipa_base, PAGE_SIZE) || + !IS_ALIGNED(args->populate_ipa_size, PAGE_SIZE)) + return -EINVAL; + + ipa_base = args->populate_ipa_base; + ipa_end = ipa_base + args->populate_ipa_size; + + if (ipa_end < ipa_base) + return -EINVAL; + + return populate_par_region(kvm, ipa_base, ipa_end); +} + static int set_ipa_state(struct kvm_vcpu *vcpu, unsigned long ipa, unsigned long end, @@ -748,6 +1102,18 @@ int kvm_realm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) r = kvm_init_ipa_range_realm(kvm, &args); break; } + case KVM_CAP_ARM_RME_POPULATE_REALM: { + struct kvm_cap_arm_rme_populate_realm_args args; + void __user *argp = u64_to_user_ptr(cap->args[1]); + + if (copy_from_user(&args, argp, sizeof(args))) { + r = -EFAULT; + break; + } + + r = kvm_populate_realm(kvm, &args); + break; + } default: r = -EINVAL; break; -- 2.34.1