/* * QEMU SEV support * * Copyright Advanced Micro Devices 2016-2018 * * Author: * Brijesh Singh * * This work is licensed under the terms of the GNU GPL, version 2 or later. * See the COPYING file in the top-level directory. * */ #include "qemu/osdep.h" #include #include #include #include "qapi/error.h" #include "qom/object_interfaces.h" #include "qemu/base64.h" #include "qemu/module.h" #include "qemu/uuid.h" #include "crypto/hash.h" #include "sysemu/kvm.h" #include "sev.h" #include "sysemu/sysemu.h" #include "sysemu/runstate.h" #include "trace.h" #include "migration/blocker.h" #include "qom/object.h" #include "monitor/monitor.h" #include "monitor/hmp-target.h" #include "qapi/qapi-commands-misc-target.h" #include "exec/confidential-guest-support.h" #include "hw/i386/pc.h" #include "exec/address-spaces.h" #define TYPE_SEV_GUEST "sev-guest" OBJECT_DECLARE_SIMPLE_TYPE(SevGuestState, SEV_GUEST) /** * SevGuestState: * * The SevGuestState object is used for creating and managing a SEV * guest. * * # $QEMU \ * -object sev-guest,id=sev0 \ * -machine ...,memory-encryption=sev0 */ struct SevGuestState { ConfidentialGuestSupport parent_obj; /* configuration parameters */ char *sev_device; uint32_t policy; char *dh_cert_file; char *session_file; uint32_t cbitpos; uint32_t reduced_phys_bits; bool kernel_hashes; /* runtime state */ uint32_t handle; uint8_t api_major; uint8_t api_minor; uint8_t build_id; int sev_fd; SevState state; gchar *measurement; uint32_t reset_cs; uint32_t reset_ip; bool reset_data_valid; }; #define DEFAULT_GUEST_POLICY 0x1 /* disable debug */ #define DEFAULT_SEV_DEVICE "/dev/sev" #define SEV_INFO_BLOCK_GUID "00f771de-1a7e-4fcb-890e-68c77e2fb44e" typedef struct __attribute__((__packed__)) SevInfoBlock { /* SEV-ES Reset Vector Address */ uint32_t reset_addr; } SevInfoBlock; #define SEV_HASH_TABLE_RV_GUID "7255371f-3a3b-4b04-927b-1da6efa8d454" typedef struct QEMU_PACKED SevHashTableDescriptor { /* SEV hash table area guest address */ uint32_t base; /* SEV hash table area size (in bytes) */ uint32_t size; } SevHashTableDescriptor; /* hard code sha256 digest size */ #define HASH_SIZE 32 typedef struct QEMU_PACKED SevHashTableEntry { QemuUUID guid; uint16_t len; uint8_t hash[HASH_SIZE]; } SevHashTableEntry; typedef struct QEMU_PACKED SevHashTable { QemuUUID guid; uint16_t len; SevHashTableEntry cmdline; SevHashTableEntry initrd; SevHashTableEntry kernel; } SevHashTable; /* * Data encrypted by sev_encrypt_flash() must be padded to a multiple of * 16 bytes. */ typedef struct QEMU_PACKED PaddedSevHashTable { SevHashTable ht; uint8_t padding[ROUND_UP(sizeof(SevHashTable), 16) - sizeof(SevHashTable)]; } PaddedSevHashTable; QEMU_BUILD_BUG_ON(sizeof(PaddedSevHashTable) % 16 != 0); static SevGuestState *sev_guest; static Error *sev_mig_blocker; static const char *const sev_fw_errlist[] = { [SEV_RET_SUCCESS] = "", [SEV_RET_INVALID_PLATFORM_STATE] = "Platform state is invalid", [SEV_RET_INVALID_GUEST_STATE] = "Guest state is invalid", [SEV_RET_INAVLID_CONFIG] = "Platform configuration is invalid", [SEV_RET_INVALID_LEN] = "Buffer too small", [SEV_RET_ALREADY_OWNED] = "Platform is already owned", [SEV_RET_INVALID_CERTIFICATE] = "Certificate is invalid", [SEV_RET_POLICY_FAILURE] = "Policy is not allowed", [SEV_RET_INACTIVE] = "Guest is not active", [SEV_RET_INVALID_ADDRESS] = "Invalid address", [SEV_RET_BAD_SIGNATURE] = "Bad signature", [SEV_RET_BAD_MEASUREMENT] = "Bad measurement", [SEV_RET_ASID_OWNED] = "ASID is already owned", [SEV_RET_INVALID_ASID] = "Invalid ASID", [SEV_RET_WBINVD_REQUIRED] = "WBINVD is required", [SEV_RET_DFFLUSH_REQUIRED] = "DF_FLUSH is required", [SEV_RET_INVALID_GUEST] = "Guest handle is invalid", [SEV_RET_INVALID_COMMAND] = "Invalid command", [SEV_RET_ACTIVE] = "Guest is active", [SEV_RET_HWSEV_RET_PLATFORM] = "Hardware error", [SEV_RET_HWSEV_RET_UNSAFE] = "Hardware unsafe", [SEV_RET_UNSUPPORTED] = "Feature not supported", [SEV_RET_INVALID_PARAM] = "Invalid parameter", [SEV_RET_RESOURCE_LIMIT] = "Required firmware resource depleted", [SEV_RET_SECURE_DATA_INVALID] = "Part-specific integrity check failure", }; #define SEV_FW_MAX_ERROR ARRAY_SIZE(sev_fw_errlist) static int sev_ioctl(int fd, int cmd, void *data, int *error) { int r; struct kvm_sev_cmd input; memset(&input, 0x0, sizeof(input)); input.id = cmd; input.sev_fd = fd; input.data = (__u64)(unsigned long)data; r = kvm_vm_ioctl(kvm_state, KVM_MEMORY_ENCRYPT_OP, &input); if (error) { *error = input.error; } return r; } static int sev_platform_ioctl(int fd, int cmd, void *data, int *error) { int r; struct sev_issue_cmd arg; arg.cmd = cmd; arg.data = (unsigned long)data; r = ioctl(fd, SEV_ISSUE_CMD, &arg); if (error) { *error = arg.error; } return r; } static const char * fw_error_to_str(int code) { if (code < 0 || code >= SEV_FW_MAX_ERROR) { return "unknown error"; } return sev_fw_errlist[code]; } static bool sev_check_state(const SevGuestState *sev, SevState state) { assert(sev); return sev->state == state ? true : false; } static void sev_set_guest_state(SevGuestState *sev, SevState new_state) { assert(new_state < SEV_STATE__MAX); assert(sev); trace_kvm_sev_change_state(SevState_str(sev->state), SevState_str(new_state)); sev->state = new_state; } static void sev_ram_block_added(RAMBlockNotifier *n, void *host, size_t size, size_t max_size) { int r; struct kvm_enc_region range; ram_addr_t offset; MemoryRegion *mr; /* * The RAM device presents a memory region that should be treated * as IO region and should not be pinned. */ mr = memory_region_from_host(host, &offset); if (mr && memory_region_is_ram_device(mr)) { return; } range.addr = (__u64)(unsigned long)host; range.size = max_size; trace_kvm_memcrypt_register_region(host, max_size); r = kvm_vm_ioctl(kvm_state, KVM_MEMORY_ENCRYPT_REG_REGION, &range); if (r) { error_report("%s: failed to register region (%p+%#zx) error '%s'", __func__, host, max_size, strerror(errno)); exit(1); } } static void sev_ram_block_removed(RAMBlockNotifier *n, void *host, size_t size, size_t max_size) { int r; struct kvm_enc_region range; ram_addr_t offset; MemoryRegion *mr; /* * The RAM device presents a memory region that should be treated * as IO region and should not have been pinned. */ mr = memory_region_from_host(host, &offset); if (mr && memory_region_is_ram_device(mr)) { return; } range.addr = (__u64)(unsigned long)host; range.size = max_size; trace_kvm_memcrypt_unregister_region(host, max_size); r = kvm_vm_ioctl(kvm_state, KVM_MEMORY_ENCRYPT_UNREG_REGION, &range); if (r) { error_report("%s: failed to unregister region (%p+%#zx)", __func__, host, max_size); } } static struct RAMBlockNotifier sev_ram_notifier = { .ram_block_added = sev_ram_block_added, .ram_block_removed = sev_ram_block_removed, }; static void sev_guest_finalize(Object *obj) { } static char * sev_guest_get_session_file(Object *obj, Error **errp) { SevGuestState *s = SEV_GUEST(obj); return s->session_file ? g_strdup(s->session_file) : NULL; } static void sev_guest_set_session_file(Object *obj, const char *value, Error **errp) { SevGuestState *s = SEV_GUEST(obj); s->session_file = g_strdup(value); } static char * sev_guest_get_dh_cert_file(Object *obj, Error **errp) { SevGuestState *s = SEV_GUEST(obj); return g_strdup(s->dh_cert_file); } static void sev_guest_set_dh_cert_file(Object *obj, const char *value, Error **errp) { SevGuestState *s = SEV_GUEST(obj); s->dh_cert_file = g_strdup(value); } static char * sev_guest_get_sev_device(Object *obj, Error **errp) { SevGuestState *sev = SEV_GUEST(obj); return g_strdup(sev->sev_device); } static void sev_guest_set_sev_device(Object *obj, const char *value, Error **errp) { SevGuestState *sev = SEV_GUEST(obj); sev->sev_device = g_strdup(value); } static bool sev_guest_get_kernel_hashes(Object *obj, Error **errp) { SevGuestState *sev = SEV_GUEST(obj); return sev->kernel_hashes; } static void sev_guest_set_kernel_hashes(Object *obj, bool value, Error **errp) { SevGuestState *sev = SEV_GUEST(obj); sev->kernel_hashes = value; } static void sev_guest_class_init(ObjectClass *oc, void *data) { object_class_property_add_str(oc, "sev-device", sev_guest_get_sev_device, sev_guest_set_sev_device); object_class_property_set_description(oc, "sev-device", "SEV device to use"); object_class_property_add_str(oc, "dh-cert-file", sev_guest_get_dh_cert_file, sev_guest_set_dh_cert_file); object_class_property_set_description(oc, "dh-cert-file", "guest owners DH certificate (encoded with base64)"); object_class_property_add_str(oc, "session-file", sev_guest_get_session_file, sev_guest_set_session_file); object_class_property_set_description(oc, "session-file", "guest owners session parameters (encoded with base64)"); object_class_property_add_bool(oc, "kernel-hashes", sev_guest_get_kernel_hashes, sev_guest_set_kernel_hashes); object_class_property_set_description(oc, "kernel-hashes", "add kernel hashes to guest firmware for measured Linux boot"); } static void sev_guest_instance_init(Object *obj) { SevGuestState *sev = SEV_GUEST(obj); sev->sev_device = g_strdup(DEFAULT_SEV_DEVICE); sev->policy = DEFAULT_GUEST_POLICY; object_property_add_uint32_ptr(obj, "policy", &sev->policy, OBJ_PROP_FLAG_READWRITE); object_property_add_uint32_ptr(obj, "handle", &sev->handle, OBJ_PROP_FLAG_READWRITE); object_property_add_uint32_ptr(obj, "cbitpos", &sev->cbitpos, OBJ_PROP_FLAG_READWRITE); object_property_add_uint32_ptr(obj, "reduced-phys-bits", &sev->reduced_phys_bits, OBJ_PROP_FLAG_READWRITE); } /* sev guest info */ static const TypeInfo sev_guest_info = { .parent = TYPE_CONFIDENTIAL_GUEST_SUPPORT, .name = TYPE_SEV_GUEST, .instance_size = sizeof(SevGuestState), .instance_finalize = sev_guest_finalize, .class_init = sev_guest_class_init, .instance_init = sev_guest_instance_init, .interfaces = (InterfaceInfo[]) { { TYPE_USER_CREATABLE }, { } } }; bool sev_enabled(void) { return !!sev_guest; } bool sev_es_enabled(void) { return sev_enabled() && (sev_guest->policy & SEV_POLICY_ES); } uint32_t sev_get_cbit_position(void) { return sev_guest ? sev_guest->cbitpos : 0; } uint32_t sev_get_reduced_phys_bits(void) { return sev_guest ? sev_guest->reduced_phys_bits : 0; } static SevInfo *sev_get_info(void) { SevInfo *info; info = g_new0(SevInfo, 1); info->enabled = sev_enabled(); if (info->enabled) { info->api_major = sev_guest->api_major; info->api_minor = sev_guest->api_minor; info->build_id = sev_guest->build_id; info->policy = sev_guest->policy; info->state = sev_guest->state; info->handle = sev_guest->handle; } return info; } SevInfo *qmp_query_sev(Error **errp) { SevInfo *info; info = sev_get_info(); if (!info) { error_setg(errp, "SEV feature is not available"); return NULL; } return info; } void hmp_info_sev(Monitor *mon, const QDict *qdict) { SevInfo *info = sev_get_info(); if (info && info->enabled) { monitor_printf(mon, "handle: %d\n", info->handle); monitor_printf(mon, "state: %s\n", SevState_str(info->state)); monitor_printf(mon, "build: %d\n", info->build_id); monitor_printf(mon, "api version: %d.%d\n", info->api_major, info->api_minor); monitor_printf(mon, "debug: %s\n", info->policy & SEV_POLICY_NODBG ? "off" : "on"); monitor_printf(mon, "key-sharing: %s\n", info->policy & SEV_POLICY_NOKS ? "off" : "on"); } else { monitor_printf(mon, "SEV is not enabled\n"); } qapi_free_SevInfo(info); } static int sev_get_pdh_info(int fd, guchar **pdh, size_t *pdh_len, guchar **cert_chain, size_t *cert_chain_len, Error **errp) { guchar *pdh_data = NULL; guchar *cert_chain_data = NULL; struct sev_user_data_pdh_cert_export export = {}; int err, r; /* query the certificate length */ r = sev_platform_ioctl(fd, SEV_PDH_CERT_EXPORT, &export, &err); if (r < 0) { if (err != SEV_RET_INVALID_LEN) { error_setg(errp, "SEV: Failed to export PDH cert" " ret=%d fw_err=%d (%s)", r, err, fw_error_to_str(err)); return 1; } } pdh_data = g_new(guchar, export.pdh_cert_len); cert_chain_data = g_new(guchar, export.cert_chain_len); export.pdh_cert_address = (unsigned long)pdh_data; export.cert_chain_address = (unsigned long)cert_chain_data; r = sev_platform_ioctl(fd, SEV_PDH_CERT_EXPORT, &export, &err); if (r < 0) { error_setg(errp, "SEV: Failed to export PDH cert ret=%d fw_err=%d (%s)", r, err, fw_error_to_str(err)); goto e_free; } *pdh = pdh_data; *pdh_len = export.pdh_cert_len; *cert_chain = cert_chain_data; *cert_chain_len = export.cert_chain_len; return 0; e_free: g_free(pdh_data); g_free(cert_chain_data); return 1; } static int sev_get_cpu0_id(int fd, guchar **id, size_t *id_len, Error **errp) { guchar *id_data; struct sev_user_data_get_id2 get_id2 = {}; int err, r; /* query the ID length */ r = sev_platform_ioctl(fd, SEV_GET_ID2, &get_id2, &err); if (r < 0 && err != SEV_RET_INVALID_LEN) { error_setg(errp, "SEV: Failed to get ID ret=%d fw_err=%d (%s)", r, err, fw_error_to_str(err)); return 1; } id_data = g_new(guchar, get_id2.length); get_id2.address = (unsigned long)id_data; r = sev_platform_ioctl(fd, SEV_GET_ID2, &get_id2, &err); if (r < 0) { error_setg(errp, "SEV: Failed to get ID ret=%d fw_err=%d (%s)", r, err, fw_error_to_str(err)); goto err; } *id = id_data; *id_len = get_id2.length; return 0; err: g_free(id_data); return 1; } static SevCapability *sev_get_capabilities(Error **errp) { SevCapability *cap = NULL; guchar *pdh_data = NULL; guchar *cert_chain_data = NULL; guchar *cpu0_id_data = NULL; size_t pdh_len = 0, cert_chain_len = 0, cpu0_id_len = 0; uint32_t ebx; int fd; if (!kvm_enabled()) { error_setg(errp, "KVM not enabled"); return NULL; } if (kvm_vm_ioctl(kvm_state, KVM_MEMORY_ENCRYPT_OP, NULL) < 0) { error_setg(errp, "SEV is not enabled in KVM"); return NULL; } fd = open(DEFAULT_SEV_DEVICE, O_RDWR); if (fd < 0) { error_setg_errno(errp, errno, "SEV: Failed to open %s", DEFAULT_SEV_DEVICE); return NULL; } if (sev_get_pdh_info(fd, &pdh_data, &pdh_len, &cert_chain_data, &cert_chain_len, errp)) { goto out; } if (sev_get_cpu0_id(fd, &cpu0_id_data, &cpu0_id_len, errp)) { goto out; } cap = g_new0(SevCapability, 1); cap->pdh = g_base64_encode(pdh_data, pdh_len); cap->cert_chain = g_base64_encode(cert_chain_data, cert_chain_len); cap->cpu0_id = g_base64_encode(cpu0_id_data, cpu0_id_len); host_cpuid(0x8000001F, 0, NULL, &ebx, NULL, NULL); cap->cbitpos = ebx & 0x3f; /* * When SEV feature is enabled, we loose one bit in guest physical * addressing. */ cap->reduced_phys_bits = 1; out: g_free(cpu0_id_data); g_free(pdh_data); g_free(cert_chain_data); close(fd); return cap; } SevCapability *qmp_query_sev_capabilities(Error **errp) { return sev_get_capabilities(errp); } static SevAttestationReport *sev_get_attestation_report(const char *mnonce, Error **errp) { struct kvm_sev_attestation_report input = {}; SevAttestationReport *report = NULL; SevGuestState *sev = sev_guest; g_autofree guchar *data = NULL; g_autofree guchar *buf = NULL; gsize len; int err = 0, ret; if (!sev_enabled()) { error_setg(errp, "SEV is not enabled"); return NULL; } /* lets decode the mnonce string */ buf = g_base64_decode(mnonce, &len); if (!buf) { error_setg(errp, "SEV: failed to decode mnonce input"); return NULL; } /* verify the input mnonce length */ if (len != sizeof(input.mnonce)) { error_setg(errp, "SEV: mnonce must be %zu bytes (got %" G_GSIZE_FORMAT ")", sizeof(input.mnonce), len); return NULL; } /* Query the report length */ ret = sev_ioctl(sev->sev_fd, KVM_SEV_GET_ATTESTATION_REPORT, &input, &err); if (ret < 0) { if (err != SEV_RET_INVALID_LEN) { error_setg(errp, "SEV: Failed to query the attestation report" " length ret=%d fw_err=%d (%s)", ret, err, fw_error_to_str(err)); return NULL; } } data = g_malloc(input.len); input.uaddr = (unsigned long)data; memcpy(input.mnonce, buf, sizeof(input.mnonce)); /* Query the report */ ret = sev_ioctl(sev->sev_fd, KVM_SEV_GET_ATTESTATION_REPORT, &input, &err); if (ret) { error_setg_errno(errp, errno, "SEV: Failed to get attestation report" " ret=%d fw_err=%d (%s)", ret, err, fw_error_to_str(err)); return NULL; } report = g_new0(SevAttestationReport, 1); report->data = g_base64_encode(data, input.len); trace_kvm_sev_attestation_report(mnonce, report->data); return report; } SevAttestationReport *qmp_query_sev_attestation_report(const char *mnonce, Error **errp) { return sev_get_attestation_report(mnonce, errp); } static int sev_read_file_base64(const char *filename, guchar **data, gsize *len) { gsize sz; g_autofree gchar *base64 = NULL; GError *error = NULL; if (!g_file_get_contents(filename, &base64, &sz, &error)) { error_report("SEV: Failed to read '%s' (%s)", filename, error->message); g_error_free(error); return -1; } *data = g_base64_decode(base64, len); return 0; } static int sev_launch_start(SevGuestState *sev) { gsize sz; int ret = 1; int fw_error, rc; struct kvm_sev_launch_start start = { .handle = sev->handle, .policy = sev->policy }; guchar *session = NULL, *dh_cert = NULL; if (sev->session_file) { if (sev_read_file_base64(sev->session_file, &session, &sz) < 0) { goto out; } start.session_uaddr = (unsigned long)session; start.session_len = sz; } if (sev->dh_cert_file) { if (sev_read_file_base64(sev->dh_cert_file, &dh_cert, &sz) < 0) { goto out; } start.dh_uaddr = (unsigned long)dh_cert; start.dh_len = sz; } trace_kvm_sev_launch_start(start.policy, session, dh_cert); rc = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_START, &start, &fw_error); if (rc < 0) { error_report("%s: LAUNCH_START ret=%d fw_error=%d '%s'", __func__, ret, fw_error, fw_error_to_str(fw_error)); goto out; } sev_set_guest_state(sev, SEV_STATE_LAUNCH_UPDATE); sev->handle = start.handle; ret = 0; out: g_free(session); g_free(dh_cert); return ret; } static int sev_launch_update_data(SevGuestState *sev, uint8_t *addr, uint64_t len) { int ret, fw_error; struct kvm_sev_launch_update_data update; if (!addr || !len) { return 1; } update.uaddr = (__u64)(unsigned long)addr; update.len = len; trace_kvm_sev_launch_update_data(addr, len); ret = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_UPDATE_DATA, &update, &fw_error); if (ret) { error_report("%s: LAUNCH_UPDATE ret=%d fw_error=%d '%s'", __func__, ret, fw_error, fw_error_to_str(fw_error)); } return ret; } static int sev_launch_update_vmsa(SevGuestState *sev) { int ret, fw_error; ret = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_UPDATE_VMSA, NULL, &fw_error); if (ret) { error_report("%s: LAUNCH_UPDATE_VMSA ret=%d fw_error=%d '%s'", __func__, ret, fw_error, fw_error_to_str(fw_error)); } return ret; } static void sev_launch_get_measure(Notifier *notifier, void *unused) { SevGuestState *sev = sev_guest; int ret, error; g_autofree guchar *data = NULL; struct kvm_sev_launch_measure measurement = {}; if (!sev_check_state(sev, SEV_STATE_LAUNCH_UPDATE)) { return; } if (sev_es_enabled()) { /* measure all the VM save areas before getting launch_measure */ ret = sev_launch_update_vmsa(sev); if (ret) { exit(1); } } /* query the measurement blob length */ ret = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_MEASURE, &measurement, &error); if (!measurement.len) { error_report("%s: LAUNCH_MEASURE ret=%d fw_error=%d '%s'", __func__, ret, error, fw_error_to_str(errno)); return; } data = g_new0(guchar, measurement.len); measurement.uaddr = (unsigned long)data; /* get the measurement blob */ ret = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_MEASURE, &measurement, &error); if (ret) { error_report("%s: LAUNCH_MEASURE ret=%d fw_error=%d '%s'", __func__, ret, error, fw_error_to_str(errno)); return; } sev_set_guest_state(sev, SEV_STATE_LAUNCH_SECRET); /* encode the measurement value and emit the event */ sev->measurement = g_base64_encode(data, measurement.len); trace_kvm_sev_launch_measurement(sev->measurement); } static char *sev_get_launch_measurement(void) { if (sev_guest && sev_guest->state >= SEV_STATE_LAUNCH_SECRET) { return g_strdup(sev_guest->measurement); } return NULL; } SevLaunchMeasureInfo *qmp_query_sev_launch_measure(Error **errp) { char *data; SevLaunchMeasureInfo *info; data = sev_get_launch_measurement(); if (!data) { error_setg(errp, "SEV launch measurement is not available"); return NULL; } info = g_malloc0(sizeof(*info)); info->data = data; return info; } static Notifier sev_machine_done_notify = { .notify = sev_launch_get_measure, }; static void sev_launch_finish(SevGuestState *sev) { int ret, error; trace_kvm_sev_launch_finish(); ret = sev_ioctl(sev->sev_fd, KVM_SEV_LAUNCH_FINISH, 0, &error); if (ret) { error_report("%s: LAUNCH_FINISH ret=%d fw_error=%d '%s'", __func__, ret, error, fw_error_to_str(error)); exit(1); } sev_set_guest_state(sev, SEV_STATE_RUNNING); /* add migration blocker */ error_setg(&sev_mig_blocker, "SEV: Migration is not implemented"); migrate_add_blocker(sev_mig_blocker, &error_fatal); } static void sev_vm_state_change(void *opaque, bool running, RunState state) { SevGuestState *sev = opaque; if (running) { if (!sev_check_state(sev, SEV_STATE_RUNNING)) { sev_launch_finish(sev); } } } int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) { SevGuestState *sev = (SevGuestState *)object_dynamic_cast(OBJECT(cgs), TYPE_SEV_GUEST); char *devname; int ret, fw_error, cmd; uint32_t ebx; uint32_t host_cbitpos; struct sev_user_data_status status = {}; if (!sev) { return 0; } ret = ram_block_discard_disable(true); if (ret) { error_report("%s: cannot disable RAM discard", __func__); return -1; } sev_guest = sev; sev->state = SEV_STATE_UNINIT; host_cpuid(0x8000001F, 0, NULL, &ebx, NULL, NULL); host_cbitpos = ebx & 0x3f; if (host_cbitpos != sev->cbitpos) { error_setg(errp, "%s: cbitpos check failed, host '%d' requested '%d'", __func__, host_cbitpos, sev->cbitpos); goto err; } if (sev->reduced_phys_bits < 1) { error_setg(errp, "%s: reduced_phys_bits check failed, it should be >=1," " requested '%d'", __func__, sev->reduced_phys_bits); goto err; } devname = object_property_get_str(OBJECT(sev), "sev-device", NULL); sev->sev_fd = open(devname, O_RDWR); if (sev->sev_fd < 0) { error_setg(errp, "%s: Failed to open %s '%s'", __func__, devname, strerror(errno)); g_free(devname); goto err; } g_free(devname); ret = sev_platform_ioctl(sev->sev_fd, SEV_PLATFORM_STATUS, &status, &fw_error); if (ret) { error_setg(errp, "%s: failed to get platform status ret=%d " "fw_error='%d: %s'", __func__, ret, fw_error, fw_error_to_str(fw_error)); goto err; } sev->build_id = status.build; sev->api_major = status.api_major; sev->api_minor = status.api_minor; if (sev_es_enabled()) { if (!kvm_kernel_irqchip_allowed()) { error_report("%s: SEV-ES guests require in-kernel irqchip support", __func__); goto err; } if (!(status.flags & SEV_STATUS_FLAGS_CONFIG_ES)) { error_report("%s: guest policy requires SEV-ES, but " "host SEV-ES support unavailable", __func__); goto err; } cmd = KVM_SEV_ES_INIT; } else { cmd = KVM_SEV_INIT; } trace_kvm_sev_init(); ret = sev_ioctl(sev->sev_fd, cmd, NULL, &fw_error); if (ret) { error_setg(errp, "%s: failed to initialize ret=%d fw_error=%d '%s'", __func__, ret, fw_error, fw_error_to_str(fw_error)); goto err; } ret = sev_launch_start(sev); if (ret) { error_setg(errp, "%s: failed to create encryption context", __func__); goto err; } ram_block_notifier_add(&sev_ram_notifier); qemu_add_machine_init_done_notifier(&sev_machine_done_notify); qemu_add_vm_change_state_handler(sev_vm_state_change, sev); cgs->ready = true; return 0; err: sev_guest = NULL; ram_block_discard_disable(false); return -1; } int sev_encrypt_flash(uint8_t *ptr, uint64_t len, Error **errp) { if (!sev_guest) { return 0; } /* if SEV is in update state then encrypt the data else do nothing */ if (sev_check_state(sev_guest, SEV_STATE_LAUNCH_UPDATE)) { int ret = sev_launch_update_data(sev_guest, ptr, len); if (ret < 0) { error_setg(errp, "SEV: Failed to encrypt pflash rom"); return ret; } } return 0; } int sev_inject_launch_secret(const char *packet_hdr, const char *secret, uint64_t gpa, Error **errp) { struct kvm_sev_launch_secret input; g_autofree guchar *data = NULL, *hdr = NULL; int error, ret = 1; void *hva; gsize hdr_sz = 0, data_sz = 0; MemoryRegion *mr = NULL; if (!sev_guest) { error_setg(errp, "SEV not enabled for guest"); return 1; } /* secret can be injected only in this state */ if (!sev_check_state(sev_guest, SEV_STATE_LAUNCH_SECRET)) { error_setg(errp, "SEV: Not in correct state. (LSECRET) %x", sev_guest->state); return 1; } hdr = g_base64_decode(packet_hdr, &hdr_sz); if (!hdr || !hdr_sz) { error_setg(errp, "SEV: Failed to decode sequence header"); return 1; } data = g_base64_decode(secret, &data_sz); if (!data || !data_sz) { error_setg(errp, "SEV: Failed to decode data"); return 1; } hva = gpa2hva(&mr, gpa, data_sz, errp); if (!hva) { error_prepend(errp, "SEV: Failed to calculate guest address: "); return 1; } input.hdr_uaddr = (uint64_t)(unsigned long)hdr; input.hdr_len = hdr_sz; input.trans_uaddr = (uint64_t)(unsigned long)data; input.trans_len = data_sz; input.guest_uaddr = (uint64_t)(unsigned long)hva; input.guest_len = data_sz; trace_kvm_sev_launch_secret(gpa, input.guest_uaddr, input.trans_uaddr, input.trans_len); ret = sev_ioctl(sev_guest->sev_fd, KVM_SEV_LAUNCH_SECRET, &input, &error); if (ret) { error_setg(errp, "SEV: failed to inject secret ret=%d fw_error=%d '%s'", ret, error, fw_error_to_str(error)); return ret; } return 0; } #define SEV_SECRET_GUID "4c2eb361-7d9b-4cc3-8081-127c90d3d294" struct sev_secret_area { uint32_t base; uint32_t size; }; void qmp_sev_inject_launch_secret(const char *packet_hdr, const char *secret, bool has_gpa, uint64_t gpa, Error **errp) { if (!sev_enabled()) { error_setg(errp, "SEV not enabled for guest"); return; } if (!has_gpa) { uint8_t *data; struct sev_secret_area *area; if (!pc_system_ovmf_table_find(SEV_SECRET_GUID, &data, NULL)) { error_setg(errp, "SEV: no secret area found in OVMF," " gpa must be specified."); return; } area = (struct sev_secret_area *)data; gpa = area->base; } sev_inject_launch_secret(packet_hdr, secret, gpa, errp); } static int sev_es_parse_reset_block(SevInfoBlock *info, uint32_t *addr) { if (!info->reset_addr) { error_report("SEV-ES reset address is zero"); return 1; } *addr = info->reset_addr; return 0; } static int sev_es_find_reset_vector(void *flash_ptr, uint64_t flash_size, uint32_t *addr) { QemuUUID info_guid, *guid; SevInfoBlock *info; uint8_t *data; uint16_t *len; /* * Initialize the address to zero. An address of zero with a successful * return code indicates that SEV-ES is not active. */ *addr = 0; /* * Extract the AP reset vector for SEV-ES guests by locating the SEV GUID. * The SEV GUID is located on its own (original implementation) or within * the Firmware GUID Table (new implementation), either of which are * located 32 bytes from the end of the flash. * * Check the Firmware GUID Table first. */ if (pc_system_ovmf_table_find(SEV_INFO_BLOCK_GUID, &data, NULL)) { return sev_es_parse_reset_block((SevInfoBlock *)data, addr); } /* * SEV info block not found in the Firmware GUID Table (or there isn't * a Firmware GUID Table), fall back to the original implementation. */ data = flash_ptr + flash_size - 0x20; qemu_uuid_parse(SEV_INFO_BLOCK_GUID, &info_guid); info_guid = qemu_uuid_bswap(info_guid); /* GUIDs are LE */ guid = (QemuUUID *)(data - sizeof(info_guid)); if (!qemu_uuid_is_equal(guid, &info_guid)) { error_report("SEV information block/Firmware GUID Table block not found in pflash rom"); return 1; } len = (uint16_t *)((uint8_t *)guid - sizeof(*len)); info = (SevInfoBlock *)(data - le16_to_cpu(*len)); return sev_es_parse_reset_block(info, addr); } void sev_es_set_reset_vector(CPUState *cpu) { X86CPU *x86; CPUX86State *env; /* Only update if we have valid reset information */ if (!sev_guest || !sev_guest->reset_data_valid) { return; } /* Do not update the BSP reset state */ if (cpu->cpu_index == 0) { return; } x86 = X86_CPU(cpu); env = &x86->env; cpu_x86_load_seg_cache(env, R_CS, 0xf000, sev_guest->reset_cs, 0xffff, DESC_P_MASK | DESC_S_MASK | DESC_CS_MASK | DESC_R_MASK | DESC_A_MASK); env->eip = sev_guest->reset_ip; } int sev_es_save_reset_vector(void *flash_ptr, uint64_t flash_size) { CPUState *cpu; uint32_t addr; int ret; if (!sev_es_enabled()) { return 0; } addr = 0; ret = sev_es_find_reset_vector(flash_ptr, flash_size, &addr); if (ret) { return ret; } if (addr) { sev_guest->reset_cs = addr & 0xffff0000; sev_guest->reset_ip = addr & 0x0000ffff; sev_guest->reset_data_valid = true; CPU_FOREACH(cpu) { sev_es_set_reset_vector(cpu); } } return 0; } static const QemuUUID sev_hash_table_header_guid = { .data = UUID_LE(0x9438d606, 0x4f22, 0x4cc9, 0xb4, 0x79, 0xa7, 0x93, 0xd4, 0x11, 0xfd, 0x21) }; static const QemuUUID sev_kernel_entry_guid = { .data = UUID_LE(0x4de79437, 0xabd2, 0x427f, 0xb8, 0x35, 0xd5, 0xb1, 0x72, 0xd2, 0x04, 0x5b) }; static const QemuUUID sev_initrd_entry_guid = { .data = UUID_LE(0x44baf731, 0x3a2f, 0x4bd7, 0x9a, 0xf1, 0x41, 0xe2, 0x91, 0x69, 0x78, 0x1d) }; static const QemuUUID sev_cmdline_entry_guid = { .data = UUID_LE(0x97d02dd8, 0xbd20, 0x4c94, 0xaa, 0x78, 0xe7, 0x71, 0x4d, 0x36, 0xab, 0x2a) }; /* * Add the hashes of the linux kernel/initrd/cmdline to an encrypted guest page * which is included in SEV's initial memory measurement. */ bool sev_add_kernel_loader_hashes(SevKernelLoaderContext *ctx, Error **errp) { uint8_t *data; SevHashTableDescriptor *area; SevHashTable *ht; PaddedSevHashTable *padded_ht; uint8_t cmdline_hash[HASH_SIZE]; uint8_t initrd_hash[HASH_SIZE]; uint8_t kernel_hash[HASH_SIZE]; uint8_t *hashp; size_t hash_len = HASH_SIZE; hwaddr mapped_len = sizeof(*padded_ht); MemTxAttrs attrs = { 0 }; bool ret = true; /* * Only add the kernel hashes if the sev-guest configuration explicitly * stated kernel-hashes=on. */ if (!sev_guest->kernel_hashes) { return false; } if (!pc_system_ovmf_table_find(SEV_HASH_TABLE_RV_GUID, &data, NULL)) { error_setg(errp, "SEV: kernel specified but guest firmware " "has no hashes table GUID"); return false; } area = (SevHashTableDescriptor *)data; if (!area->base || area->size < sizeof(PaddedSevHashTable)) { error_setg(errp, "SEV: guest firmware hashes table area is invalid " "(base=0x%x size=0x%x)", area->base, area->size); return false; } /* * Calculate hash of kernel command-line with the terminating null byte. If * the user doesn't supply a command-line via -append, the 1-byte "\0" will * be used. */ hashp = cmdline_hash; if (qcrypto_hash_bytes(QCRYPTO_HASH_ALG_SHA256, ctx->cmdline_data, ctx->cmdline_size, &hashp, &hash_len, errp) < 0) { return false; } assert(hash_len == HASH_SIZE); /* * Calculate hash of initrd. If the user doesn't supply an initrd via * -initrd, an empty buffer will be used (ctx->initrd_size == 0). */ hashp = initrd_hash; if (qcrypto_hash_bytes(QCRYPTO_HASH_ALG_SHA256, ctx->initrd_data, ctx->initrd_size, &hashp, &hash_len, errp) < 0) { return false; } assert(hash_len == HASH_SIZE); /* Calculate hash of the kernel */ hashp = kernel_hash; struct iovec iov[2] = { { .iov_base = ctx->setup_data, .iov_len = ctx->setup_size }, { .iov_base = ctx->kernel_data, .iov_len = ctx->kernel_size } }; if (qcrypto_hash_bytesv(QCRYPTO_HASH_ALG_SHA256, iov, ARRAY_SIZE(iov), &hashp, &hash_len, errp) < 0) { return false; } assert(hash_len == HASH_SIZE); /* * Populate the hashes table in the guest's memory at the OVMF-designated * area for the SEV hashes table */ padded_ht = address_space_map(&address_space_memory, area->base, &mapped_len, true, attrs); if (!padded_ht || mapped_len != sizeof(*padded_ht)) { error_setg(errp, "SEV: cannot map hashes table guest memory area"); return false; } ht = &padded_ht->ht; ht->guid = sev_hash_table_header_guid; ht->len = sizeof(*ht); ht->cmdline.guid = sev_cmdline_entry_guid; ht->cmdline.len = sizeof(ht->cmdline); memcpy(ht->cmdline.hash, cmdline_hash, sizeof(ht->cmdline.hash)); ht->initrd.guid = sev_initrd_entry_guid; ht->initrd.len = sizeof(ht->initrd); memcpy(ht->initrd.hash, initrd_hash, sizeof(ht->initrd.hash)); ht->kernel.guid = sev_kernel_entry_guid; ht->kernel.len = sizeof(ht->kernel); memcpy(ht->kernel.hash, kernel_hash, sizeof(ht->kernel.hash)); /* zero the excess data so the measurement can be reliably calculated */ memset(padded_ht->padding, 0, sizeof(padded_ht->padding)); if (sev_encrypt_flash((uint8_t *)padded_ht, sizeof(*padded_ht), errp) < 0) { ret = false; } address_space_unmap(&address_space_memory, padded_ht, mapped_len, true, mapped_len); return ret; } static void sev_register_types(void) { type_register_static(&sev_guest_info); } type_init(sev_register_types);