The sev_save_outgoing_page() provide the implementation to encrypt the guest private pages during the transit. The routines uses the SEND_START command to create the outgoing encryption context on the first call then uses the SEND_UPDATE_DATA command to encrypt the data before writing it to the socket. While encrypting the data SEND_UPDATE_DATA produces some metadata (e.g MAC, IV). The metadata is also sent to the target machine. After migration is completed, we issue the SEND_FINISH command to transition the SEV guest state from sending to unrunnable state.
Signed-off-by: Brijesh Singh <brijesh.si...@amd.com> --- accel/kvm/kvm-all.c | 9 ++ accel/kvm/sev-stub.c | 6 ++ include/sysemu/sev.h | 2 + target/i386/sev.c | 216 +++++++++++++++++++++++++++++++++++++++ target/i386/sev_i386.h | 2 + target/i386/trace-events | 3 + 6 files changed, 238 insertions(+) diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index d0304c6947..a5b0ae9363 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -172,8 +172,17 @@ static int kvm_memcrypt_save_setup(const char *pdh, const char *plat_cert, plat_cert, amd_cert); } +static int kvm_memcrypt_save_outgoing_page(QEMUFile *f, uint8_t *ptr, + uint32_t size, + uint64_t *bytes_sent) +{ + return sev_save_outgoing_page(kvm_state->memcrypt_handle, f, ptr, size, + bytes_sent); +} + static struct MachineMemoryEncryptionOps sev_memory_encryption_ops = { .save_setup = kvm_memcrypt_save_setup, + .save_outgoing_page = kvm_memcrypt_save_outgoing_page, }; int kvm_memcrypt_encrypt_data(uint8_t *ptr, uint64_t len) diff --git a/accel/kvm/sev-stub.c b/accel/kvm/sev-stub.c index 528f8cf7f1..51b17b8141 100644 --- a/accel/kvm/sev-stub.c +++ b/accel/kvm/sev-stub.c @@ -30,3 +30,9 @@ int sev_save_setup(void *handle, const char *pdh, const char *plat_cert, { return 1; } + +int sev_save_outgoing_page(void *handle, QEMUFile *f, uint8_t *ptr, + uint32_t size, uint64_t *bytes_sent) +{ + return 1; +} diff --git a/include/sysemu/sev.h b/include/sysemu/sev.h index d5123d4fa3..f06fd203cd 100644 --- a/include/sysemu/sev.h +++ b/include/sysemu/sev.h @@ -20,4 +20,6 @@ void *sev_guest_init(const char *id); int sev_encrypt_data(void *handle, uint8_t *ptr, uint64_t len); int sev_save_setup(void *handle, const char *pdh, const char *plat_cert, const char *amd_cert); +int sev_save_outgoing_page(void *handle, QEMUFile *f, uint8_t *ptr, + uint32_t size, uint64_t *bytes_sent); #endif diff --git a/target/i386/sev.c b/target/i386/sev.c index 483d9bb0fa..1820c62a71 100644 --- a/target/i386/sev.c +++ b/target/i386/sev.c @@ -28,6 +28,7 @@ #include "trace.h" #include "migration/blocker.h" #include "migration/qemu-file.h" +#include "migration/misc.h" #define DEFAULT_GUEST_POLICY 0x1 /* disable debug */ #define DEFAULT_SEV_DEVICE "/dev/sev" @@ -774,6 +775,40 @@ error: return 1; } +static void +sev_send_finish(void) +{ + int ret, error; + + trace_kvm_sev_send_finish(); + ret = sev_ioctl(sev_state->sev_fd, KVM_SEV_SEND_FINISH, 0, &error); + if (ret) { + error_report("%s: SEND_FINISH ret=%d fw_error=%d '%s'", + __func__, ret, error, fw_error_to_str(error)); + } + + g_free(sev_state->send_packet_hdr); + sev_set_guest_state(SEV_STATE_RUNNING); +} + +static void +sev_migration_state_notifier(Notifier *notifier, void *data) +{ + MigrationState *s = data; + + if (migration_has_finished(s) || + migration_in_postcopy_after_devices(s) || + migration_has_failed(s)) { + if (sev_check_state(SEV_STATE_SEND_UPDATE)) { + sev_send_finish(); + } + } +} + +static Notifier sev_migration_state_notify = { + .notify = sev_migration_state_notifier, +}; + void * sev_guest_init(const char *id) { @@ -860,6 +895,7 @@ sev_guest_init(const char *id) 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, s); + add_migration_state_change_notifier(&sev_migration_state_notify); return s; err: @@ -881,6 +917,186 @@ sev_encrypt_data(void *handle, uint8_t *ptr, uint64_t len) return 0; } +static int +sev_get_send_session_length(void) +{ + int ret, fw_err = 0; + struct kvm_sev_send_start start = {}; + + ret = sev_ioctl(sev_state->sev_fd, KVM_SEV_SEND_START, &start, &fw_err); + if (fw_err != SEV_RET_INVALID_LEN) { + ret = -1; + error_report("%s: failed to get session length ret=%d fw_error=%d '%s'", + __func__, ret, fw_err, fw_error_to_str(fw_err)); + goto err; + } + + ret = start.session_len; +err: + return ret; +} + +static int +sev_send_start(SEVState *s, QEMUFile *f, uint64_t *bytes_sent) +{ + gsize pdh_len = 0, plat_cert_len; + int session_len, ret, fw_error; + struct kvm_sev_send_start start = { }; + guchar *pdh = NULL, *plat_cert = NULL, *session = NULL; + + if (!s->remote_pdh || !s->remote_plat_cert || !s->amd_cert_len) { + error_report("%s: missing remote PDH or PLAT_CERT", __func__); + return 1; + } + + start.pdh_cert_uaddr = (uintptr_t) s->remote_pdh; + start.pdh_cert_len = s->remote_pdh_len; + + start.plat_cert_uaddr = (uintptr_t)s->remote_plat_cert; + start.plat_cert_len = s->remote_plat_cert_len; + + start.amd_cert_uaddr = (uintptr_t)s->amd_cert; + start.amd_cert_len = s->amd_cert_len; + + /* get the session length */ + session_len = sev_get_send_session_length(); + if (session_len < 0) { + ret = 1; + goto err; + } + + session = g_new0(guchar, session_len); + start.session_uaddr = (unsigned long)session; + start.session_len = session_len; + + /* Get our PDH certificate */ + ret = sev_get_pdh_info(s->sev_fd, &pdh, &pdh_len, + &plat_cert, &plat_cert_len); + if (ret) { + error_report("Failed to get our PDH cert"); + goto err; + } + + trace_kvm_sev_send_start(start.pdh_cert_uaddr, start.pdh_cert_len, + start.plat_cert_uaddr, start.plat_cert_len, + start.amd_cert_uaddr, start.amd_cert_len); + + ret = sev_ioctl(s->sev_fd, KVM_SEV_SEND_START, &start, &fw_error); + if (ret < 0) { + error_report("%s: SEND_START ret=%d fw_error=%d '%s'", + __func__, ret, fw_error, fw_error_to_str(fw_error)); + goto err; + } + + qemu_put_be32(f, start.policy); + qemu_put_be32(f, pdh_len); + qemu_put_buffer(f, (uint8_t *)pdh, pdh_len); + qemu_put_be32(f, start.session_len); + qemu_put_buffer(f, (uint8_t *)start.session_uaddr, start.session_len); + *bytes_sent = 12 + pdh_len + start.session_len; + + sev_set_guest_state(SEV_STATE_SEND_UPDATE); + +err: + g_free(pdh); + g_free(plat_cert); + return ret; +} + +static int +sev_send_get_packet_len(int *fw_err) +{ + int ret; + struct kvm_sev_send_update_data update = {}; + + ret = sev_ioctl(sev_state->sev_fd, KVM_SEV_SEND_UPDATE_DATA, + &update, fw_err); + if (*fw_err != SEV_RET_INVALID_LEN) { + ret = -1; + error_report("%s: failed to get session length ret=%d fw_error=%d '%s'", + __func__, ret, *fw_err, fw_error_to_str(*fw_err)); + goto err; + } + + ret = update.hdr_len; + +err: + return ret; +} + +static int +sev_send_update_data(SEVState *s, QEMUFile *f, uint8_t *ptr, uint32_t size, + uint64_t *bytes_sent) +{ + int ret, fw_error; + guchar *trans; + struct kvm_sev_send_update_data update = { }; + + /* + * If this is first call then query the packet header bytes and allocate + * the packet buffer. + */ + if (!s->send_packet_hdr) { + s->send_packet_hdr_len = sev_send_get_packet_len(&fw_error); + if (s->send_packet_hdr_len < 1) { + error_report("%s: SEND_UPDATE fw_error=%d '%s'", + __func__, fw_error, fw_error_to_str(fw_error)); + return 1; + } + + s->send_packet_hdr = g_new(gchar, s->send_packet_hdr_len); + } + + /* allocate transport buffer */ + trans = g_new(guchar, size); + + update.hdr_uaddr = (uintptr_t)s->send_packet_hdr; + update.hdr_len = s->send_packet_hdr_len; + update.guest_uaddr = (uintptr_t)ptr; + update.guest_len = size; + update.trans_uaddr = (uintptr_t)trans; + update.trans_len = size; + + trace_kvm_sev_send_update_data(ptr, trans, size); + + ret = sev_ioctl(s->sev_fd, KVM_SEV_SEND_UPDATE_DATA, &update, &fw_error); + if (ret) { + error_report("%s: SEND_UPDATE_DATA ret=%d fw_error=%d '%s'", + __func__, ret, fw_error, fw_error_to_str(fw_error)); + goto err; + } + + qemu_put_be32(f, update.hdr_len); + qemu_put_buffer(f, (uint8_t *)update.hdr_uaddr, update.hdr_len); + *bytes_sent = 4 + update.hdr_len; + + qemu_put_be32(f, update.trans_len); + qemu_put_buffer(f, (uint8_t *)update.trans_uaddr, update.trans_len); + *bytes_sent += (4 + update.trans_len); + +err: + g_free(trans); + return ret; +} + +int sev_save_outgoing_page(void *handle, QEMUFile *f, uint8_t *ptr, + uint32_t sz, uint64_t *bytes_sent) +{ + SEVState *s = sev_state; + + /* + * If this is a first buffer then create outgoing encryption context + * and write our PDH, policy and session data. + */ + if (!sev_check_state(SEV_STATE_SEND_UPDATE) && + sev_send_start(s, f, bytes_sent)) { + error_report("Failed to create outgoing context"); + return 1; + } + + return sev_send_update_data(s, f, ptr, sz, bytes_sent); +} + static void sev_register_types(void) { diff --git a/target/i386/sev_i386.h b/target/i386/sev_i386.h index 32906de998..e475304f5f 100644 --- a/target/i386/sev_i386.h +++ b/target/i386/sev_i386.h @@ -87,6 +87,8 @@ struct SEVState { size_t remote_plat_cert_len; guchar *amd_cert; size_t amd_cert_len; + gchar *send_packet_hdr; + size_t send_packet_hdr_len; }; typedef struct SEVState SEVState; diff --git a/target/i386/trace-events b/target/i386/trace-events index 789c700d4a..b41516cf9f 100644 --- a/target/i386/trace-events +++ b/target/i386/trace-events @@ -15,3 +15,6 @@ kvm_sev_launch_start(int policy, void *session, void *pdh) "policy 0x%x session kvm_sev_launch_update_data(void *addr, uint64_t len) "addr %p len 0x%" PRIu64 kvm_sev_launch_measurement(const char *value) "data %s" kvm_sev_launch_finish(void) "" +kvm_sev_send_start(uint64_t pdh, int l1, uint64_t plat, int l2, uint64_t amd, int l3) "pdh 0x%" PRIx64 " len %d plat 0x%" PRIx64 " len %d amd 0x%" PRIx64 " len %d" +kvm_sev_send_update_data(void *src, void *dst, int len) "guest %p trans %p len %d" +kvm_sev_send_finish(void) "" -- 2.17.1