From patchwork Thu Jul 4 16:25:20 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thibault Ferrante X-Patchwork-Id: 1956972 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ubuntu.com (client-ip=185.125.189.65; helo=lists.ubuntu.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=patchwork.ozlabs.org) Received: from lists.ubuntu.com (lists.ubuntu.com [185.125.189.65]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4WFMT803QFz1xpP for ; Fri, 5 Jul 2024 02:25:48 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=lists.ubuntu.com) by lists.ubuntu.com with esmtp (Exim 4.86_2) (envelope-from ) id 1sPPHC-0001kv-3x; Thu, 04 Jul 2024 16:25:42 +0000 Received: from smtp-relay-canonical-0.internal ([10.131.114.83] helo=smtp-relay-canonical-0.canonical.com) by lists.ubuntu.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1sPPH8-0001hX-JG for kernel-team@lists.ubuntu.com; Thu, 04 Jul 2024 16:25:38 +0000 Received: from Q58-sff.. (2.general.thibf.uk.vpn [10.172.200.120]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-canonical-0.canonical.com (Postfix) with ESMTPSA id 5E0913F2E1; Thu, 4 Jul 2024 16:25:38 +0000 (UTC) From: Thibault Ferrante To: kernel-team@lists.ubuntu.com Subject: [SRU][N:intel][PATCH 3/4] KVM: selftests: Add library for creating and interacting with SEV guests Date: Thu, 4 Jul 2024 18:25:20 +0200 Message-ID: <20240704162521.3375266-4-thibault.ferrante@canonical.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240704162521.3375266-1-thibault.ferrante@canonical.com> References: <20240704162521.3375266-1-thibault.ferrante@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Peter Gonda BugLink: https://bugs.launchpad.net/bugs/2071628 Add a library/APIs for creating and interfacing with SEV guests, all of which need some amount of common functionality, e.g. an open file handle for the SEV driver (/dev/sev), ioctl() wrappers to pass said file handle to KVM, tracking of the C-bit, etc. Add an x86-specific hook to initialize address properties, a.k.a. the location of the C-bit. An arch specific hook is rather gross, but x86 already has a dedicated #ifdef-protected kvm_get_cpu_address_width() hook, i.e. the ugliest code already exists. Cc: Paolo Bonzini Cc: Sean Christopherson Cc: Vishal Annapurve Cc: Ackerly Tng cc: Andrew Jones Cc: Tom Lendacky Cc: Michael Roth Tested-by: Carlos Bilbao Originally-by: Michael Roth Signed-off-by: Peter Gonda Co-developed-by: Sean Christopherson Link: https://lore.kernel.org/r/20240223004258.3104051-9-seanjc@google.com Signed-off-by: Sean Christopherson (cherry picked from commit ae20eef5323cce441e8d6c64c8d10493bf3ee232) Signed-off-by: Thibault Ferrante --- tools/testing/selftests/kvm/Makefile | 1 + .../kvm/include/x86_64/kvm_util_arch.h | 2 + .../selftests/kvm/include/x86_64/processor.h | 8 ++ .../selftests/kvm/include/x86_64/sev.h | 105 +++++++++++++++++ tools/testing/selftests/kvm/lib/kvm_util.c | 1 + .../selftests/kvm/lib/x86_64/processor.c | 17 +++ tools/testing/selftests/kvm/lib/x86_64/sev.c | 110 ++++++++++++++++++ 7 files changed, 244 insertions(+) create mode 100644 tools/testing/selftests/kvm/include/x86_64/sev.h create mode 100644 tools/testing/selftests/kvm/lib/x86_64/sev.c diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 492e937fab00..4ec6f3bcb7de 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -37,6 +37,7 @@ LIBKVM_x86_64 += lib/x86_64/handlers.S LIBKVM_x86_64 += lib/x86_64/hyperv.c LIBKVM_x86_64 += lib/x86_64/memstress.c LIBKVM_x86_64 += lib/x86_64/processor.c +LIBKVM_x86_64 += lib/x86_64/sev.c LIBKVM_x86_64 += lib/x86_64/svm.c LIBKVM_x86_64 += lib/x86_64/ucall.c LIBKVM_x86_64 += lib/x86_64/vmx.c diff --git a/tools/testing/selftests/kvm/include/x86_64/kvm_util_arch.h b/tools/testing/selftests/kvm/include/x86_64/kvm_util_arch.h index cfdf8c5e2671..9f1725192aa2 100644 --- a/tools/testing/selftests/kvm/include/x86_64/kvm_util_arch.h +++ b/tools/testing/selftests/kvm/include/x86_64/kvm_util_arch.h @@ -8,6 +8,8 @@ struct kvm_vm_arch { uint64_t c_bit; uint64_t s_bit; + int sev_fd; + bool is_pt_protected; }; static inline bool __vm_arch_has_protected_memory(struct kvm_vm_arch *arch) diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index 5bca8c947c82..d2534a4a077b 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -23,6 +23,12 @@ extern bool host_cpu_is_intel; extern bool host_cpu_is_amd; +enum vm_guest_x86_subtype { + VM_SUBTYPE_NONE = 0, + VM_SUBTYPE_SEV, + VM_SUBTYPE_SEV_ES, +}; + #define NMI_VECTOR 0x02 #define X86_EFLAGS_FIXED (1u << 1) @@ -273,6 +279,7 @@ struct kvm_x86_cpu_property { #define X86_PROPERTY_MAX_EXT_LEAF KVM_X86_CPU_PROPERTY(0x80000000, 0, EAX, 0, 31) #define X86_PROPERTY_MAX_PHY_ADDR KVM_X86_CPU_PROPERTY(0x80000008, 0, EAX, 0, 7) #define X86_PROPERTY_MAX_VIRT_ADDR KVM_X86_CPU_PROPERTY(0x80000008, 0, EAX, 8, 15) +#define X86_PROPERTY_SEV_C_BIT KVM_X86_CPU_PROPERTY(0x8000001F, 0, EBX, 0, 5) #define X86_PROPERTY_PHYS_ADDR_REDUCTION KVM_X86_CPU_PROPERTY(0x8000001F, 0, EBX, 6, 11) #define X86_PROPERTY_MAX_CENTAUR_LEAF KVM_X86_CPU_PROPERTY(0xC0000000, 0, EAX, 0, 31) @@ -1059,6 +1066,7 @@ do { \ } while (0) void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits); +void kvm_init_vm_address_properties(struct kvm_vm *vm); bool vm_is_unrestricted_guest(struct kvm_vm *vm); struct ex_regs { diff --git a/tools/testing/selftests/kvm/include/x86_64/sev.h b/tools/testing/selftests/kvm/include/x86_64/sev.h new file mode 100644 index 000000000000..de5283bef752 --- /dev/null +++ b/tools/testing/selftests/kvm/include/x86_64/sev.h @@ -0,0 +1,105 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Helpers used for SEV guests + * + */ +#ifndef SELFTEST_KVM_SEV_H +#define SELFTEST_KVM_SEV_H + +#include +#include + +#include "linux/psp-sev.h" + +#include "kvm_util.h" +#include "svm_util.h" +#include "processor.h" + +enum sev_guest_state { + SEV_GUEST_STATE_UNINITIALIZED = 0, + SEV_GUEST_STATE_LAUNCH_UPDATE, + SEV_GUEST_STATE_LAUNCH_SECRET, + SEV_GUEST_STATE_RUNNING, +}; + +#define SEV_POLICY_NO_DBG (1UL << 0) +#define SEV_POLICY_ES (1UL << 2) + +void sev_vm_launch(struct kvm_vm *vm, uint32_t policy); +void sev_vm_launch_measure(struct kvm_vm *vm, uint8_t *measurement); +void sev_vm_launch_finish(struct kvm_vm *vm); + +struct kvm_vm *vm_sev_create_with_one_vcpu(uint32_t policy, void *guest_code, + struct kvm_vcpu **cpu); + +kvm_static_assert(SEV_RET_SUCCESS == 0); + +/* + * The KVM_MEMORY_ENCRYPT_OP uAPI is utter garbage and takes an "unsigned long" + * instead of a proper struct. The size of the parameter is embedded in the + * ioctl number, i.e. is ABI and thus immutable. Hack around the mess by + * creating an overlay to pass in an "unsigned long" without a cast (casting + * will make the compiler unhappy due to dereferencing an aliased pointer). + */ +#define __vm_sev_ioctl(vm, cmd, arg) \ +({ \ + int r; \ + \ + union { \ + struct kvm_sev_cmd c; \ + unsigned long raw; \ + } sev_cmd = { .c = { \ + .id = (cmd), \ + .data = (uint64_t)(arg), \ + .sev_fd = (vm)->arch.sev_fd, \ + } }; \ + \ + r = __vm_ioctl(vm, KVM_MEMORY_ENCRYPT_OP, &sev_cmd.raw); \ + r ?: sev_cmd.c.error; \ +}) + +#define vm_sev_ioctl(vm, cmd, arg) \ +({ \ + int ret = __vm_sev_ioctl(vm, cmd, arg); \ + \ + __TEST_ASSERT_VM_VCPU_IOCTL(!ret, #cmd, ret, vm); \ +}) + +static inline void sev_vm_init(struct kvm_vm *vm) +{ + vm->arch.sev_fd = open_sev_dev_path_or_exit(); + + vm_sev_ioctl(vm, KVM_SEV_INIT, NULL); +} + + +static inline void sev_es_vm_init(struct kvm_vm *vm) +{ + vm->arch.sev_fd = open_sev_dev_path_or_exit(); + + vm_sev_ioctl(vm, KVM_SEV_ES_INIT, NULL); +} + +static inline void sev_register_encrypted_memory(struct kvm_vm *vm, + struct userspace_mem_region *region) +{ + struct kvm_enc_region range = { + .addr = region->region.userspace_addr, + .size = region->region.memory_size, + }; + + vm_ioctl(vm, KVM_MEMORY_ENCRYPT_REG_REGION, &range); +} + +static inline void sev_launch_update_data(struct kvm_vm *vm, vm_paddr_t gpa, + uint64_t size) +{ + struct kvm_sev_launch_update_data update_data = { + .uaddr = (unsigned long)addr_gpa2hva(vm, gpa), + .len = size, + }; + + vm_sev_ioctl(vm, KVM_SEV_LAUNCH_UPDATE_DATA, &update_data); +} + +#endif /* SELFTEST_KVM_SEV_H */ diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index b9a82242f947..62082f967483 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -266,6 +266,7 @@ struct kvm_vm *____vm_create(struct vm_shape shape) case VM_MODE_PXXV48_4K: #ifdef __x86_64__ kvm_get_cpu_address_width(&vm->pa_bits, &vm->va_bits); + kvm_init_vm_address_properties(vm); /* * Ignore KVM support for 5-level paging (vm->va_bits == 57), * it doesn't take effect unless a CR4.LA57 is set, which it diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index 609f342cadf6..4b7fe7e1e234 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -9,6 +9,7 @@ #include "test_util.h" #include "kvm_util.h" #include "processor.h" +#include "sev.h" #ifndef NUM_INTERRUPTS #define NUM_INTERRUPTS 256 @@ -278,6 +279,9 @@ uint64_t *__vm_get_page_table_entry(struct kvm_vm *vm, uint64_t vaddr, { uint64_t *pml4e, *pdpe, *pde; + TEST_ASSERT(!vm->arch.is_pt_protected, + "Walking page tables of protected guests is impossible"); + TEST_ASSERT(*level >= PG_LEVEL_NONE && *level < PG_LEVEL_NUM, "Invalid PG_LEVEL_* '%d'", *level); @@ -573,6 +577,11 @@ void kvm_arch_vm_post_create(struct kvm_vm *vm) vm_create_irqchip(vm); sync_global_to_guest(vm, host_cpu_is_intel); sync_global_to_guest(vm, host_cpu_is_amd); + + if (vm->subtype == VM_SUBTYPE_SEV) + sev_vm_init(vm); + else if (vm->subtype == VM_SUBTYPE_SEV_ES) + sev_es_vm_init(vm); } struct kvm_vcpu *vm_arch_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id, @@ -1054,6 +1063,14 @@ void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits) } } +void kvm_init_vm_address_properties(struct kvm_vm *vm) +{ + if (vm->subtype == VM_SUBTYPE_SEV) { + vm->arch.c_bit = BIT_ULL(this_cpu_property(X86_PROPERTY_SEV_C_BIT)); + vm->gpa_tag_mask = vm->arch.c_bit; + } +} + static void set_idt_entry(struct kvm_vm *vm, int vector, unsigned long addr, int dpl, unsigned short selector) { diff --git a/tools/testing/selftests/kvm/lib/x86_64/sev.c b/tools/testing/selftests/kvm/lib/x86_64/sev.c new file mode 100644 index 000000000000..9f5a3dbb5e65 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/x86_64/sev.c @@ -0,0 +1,110 @@ +// SPDX-License-Identifier: GPL-2.0-only +#define _GNU_SOURCE /* for program_invocation_short_name */ +#include +#include + +#include "sev.h" + +/* + * sparsebit_next_clear() can return 0 if [x, 2**64-1] are all set, and the + * -1 would then cause an underflow back to 2**64 - 1. This is expected and + * correct. + * + * If the last range in the sparsebit is [x, y] and we try to iterate, + * sparsebit_next_set() will return 0, and sparsebit_next_clear() will try + * and find the first range, but that's correct because the condition + * expression would cause us to quit the loop. + */ +static void encrypt_region(struct kvm_vm *vm, struct userspace_mem_region *region) +{ + const struct sparsebit *protected_phy_pages = region->protected_phy_pages; + const vm_paddr_t gpa_base = region->region.guest_phys_addr; + const sparsebit_idx_t lowest_page_in_region = gpa_base >> vm->page_shift; + sparsebit_idx_t i, j; + + if (!sparsebit_any_set(protected_phy_pages)) + return; + + sev_register_encrypted_memory(vm, region); + + sparsebit_for_each_set_range(protected_phy_pages, i, j) { + const uint64_t size = (j - i + 1) * vm->page_size; + const uint64_t offset = (i - lowest_page_in_region) * vm->page_size; + + sev_launch_update_data(vm, gpa_base + offset, size); + } +} + +void sev_vm_launch(struct kvm_vm *vm, uint32_t policy) +{ + struct kvm_sev_launch_start launch_start = { + .policy = policy, + }; + struct userspace_mem_region *region; + struct kvm_sev_guest_status status; + int ctr; + + vm_sev_ioctl(vm, KVM_SEV_LAUNCH_START, &launch_start); + vm_sev_ioctl(vm, KVM_SEV_GUEST_STATUS, &status); + + TEST_ASSERT_EQ(status.policy, policy); + TEST_ASSERT_EQ(status.state, SEV_GUEST_STATE_LAUNCH_UPDATE); + + hash_for_each(vm->regions.slot_hash, ctr, region, slot_node) + encrypt_region(vm, region); + + vm->arch.is_pt_protected = true; +} + +void sev_vm_launch_measure(struct kvm_vm *vm, uint8_t *measurement) +{ + struct kvm_sev_launch_measure launch_measure; + struct kvm_sev_guest_status guest_status; + + launch_measure.len = 256; + launch_measure.uaddr = (__u64)measurement; + vm_sev_ioctl(vm, KVM_SEV_LAUNCH_MEASURE, &launch_measure); + + vm_sev_ioctl(vm, KVM_SEV_GUEST_STATUS, &guest_status); + TEST_ASSERT_EQ(guest_status.state, SEV_GUEST_STATE_LAUNCH_SECRET); +} + +void sev_vm_launch_finish(struct kvm_vm *vm) +{ + struct kvm_sev_guest_status status; + + vm_sev_ioctl(vm, KVM_SEV_GUEST_STATUS, &status); + TEST_ASSERT(status.state == SEV_GUEST_STATE_LAUNCH_UPDATE || + status.state == SEV_GUEST_STATE_LAUNCH_SECRET, + "Unexpected guest state: %d", status.state); + + vm_sev_ioctl(vm, KVM_SEV_LAUNCH_FINISH, NULL); + + vm_sev_ioctl(vm, KVM_SEV_GUEST_STATUS, &status); + TEST_ASSERT_EQ(status.state, SEV_GUEST_STATE_RUNNING); +} + +struct kvm_vm *vm_sev_create_with_one_vcpu(uint32_t policy, void *guest_code, + struct kvm_vcpu **cpu) +{ + struct vm_shape shape = { + .type = VM_TYPE_DEFAULT, + .mode = VM_MODE_DEFAULT, + .subtype = VM_SUBTYPE_SEV, + }; + struct kvm_vm *vm; + struct kvm_vcpu *cpus[1]; + uint8_t measurement[512]; + + vm = __vm_create_with_vcpus(shape, 1, 0, guest_code, cpus); + *cpu = cpus[0]; + + sev_vm_launch(vm, policy); + + /* TODO: Validate the measurement is as expected. */ + sev_vm_launch_measure(vm, measurement); + + sev_vm_launch_finish(vm); + + return vm; +}