diff options
Diffstat (limited to 'migration/cpr.c')
| -rw-r--r-- | migration/cpr.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/migration/cpr.c b/migration/cpr.c new file mode 100644 index 0000000..a50a57e --- /dev/null +++ b/migration/cpr.c @@ -0,0 +1,266 @@ +/* + * Copyright (c) 2021-2024 Oracle and/or its affiliates. + * + * 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 "qapi/error.h" +#include "migration/cpr.h" +#include "migration/misc.h" +#include "migration/options.h" +#include "migration/qemu-file.h" +#include "migration/savevm.h" +#include "migration/vmstate.h" +#include "system/runstate.h" +#include "trace.h" + +/*************************************************************************/ +/* cpr state container for all information to be saved. */ + +typedef QLIST_HEAD(CprFdList, CprFd) CprFdList; + +typedef struct CprState { + CprFdList fds; +} CprState; + +static CprState cpr_state; + +/****************************************************************************/ + +typedef struct CprFd { + char *name; + unsigned int namelen; + int id; + int fd; + QLIST_ENTRY(CprFd) next; +} CprFd; + +static const VMStateDescription vmstate_cpr_fd = { + .name = "cpr fd", + .version_id = 1, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_UINT32(namelen, CprFd), + VMSTATE_VBUFFER_ALLOC_UINT32(name, CprFd, 0, NULL, namelen), + VMSTATE_INT32(id, CprFd), + VMSTATE_FD(fd, CprFd), + VMSTATE_END_OF_LIST() + } +}; + +void cpr_save_fd(const char *name, int id, int fd) +{ + CprFd *elem = g_new0(CprFd, 1); + + trace_cpr_save_fd(name, id, fd); + elem->name = g_strdup(name); + elem->namelen = strlen(name) + 1; + elem->id = id; + elem->fd = fd; + QLIST_INSERT_HEAD(&cpr_state.fds, elem, next); +} + +static CprFd *find_fd(CprFdList *head, const char *name, int id) +{ + CprFd *elem; + + QLIST_FOREACH(elem, head, next) { + if (!strcmp(elem->name, name) && elem->id == id) { + return elem; + } + } + return NULL; +} + +void cpr_delete_fd(const char *name, int id) +{ + CprFd *elem = find_fd(&cpr_state.fds, name, id); + + if (elem) { + QLIST_REMOVE(elem, next); + g_free(elem->name); + g_free(elem); + } + + trace_cpr_delete_fd(name, id); +} + +int cpr_find_fd(const char *name, int id) +{ + CprFd *elem = find_fd(&cpr_state.fds, name, id); + int fd = elem ? elem->fd : -1; + + trace_cpr_find_fd(name, id, fd); + return fd; +} + +void cpr_resave_fd(const char *name, int id, int fd) +{ + CprFd *elem = find_fd(&cpr_state.fds, name, id); + int old_fd = elem ? elem->fd : -1; + + if (old_fd < 0) { + cpr_save_fd(name, id, fd); + } else if (old_fd != fd) { + error_setg(&error_fatal, + "internal error: cpr fd '%s' id %d value %d " + "already saved with a different value %d", + name, id, fd, old_fd); + } +} + +int cpr_open_fd(const char *path, int flags, const char *name, int id, + Error **errp) +{ + int fd = cpr_find_fd(name, id); + + if (fd < 0) { + fd = qemu_open(path, flags, errp); + if (fd >= 0) { + cpr_save_fd(name, id, fd); + } + } + return fd; +} + +/*************************************************************************/ +#define CPR_STATE "CprState" + +static const VMStateDescription vmstate_cpr_state = { + .name = CPR_STATE, + .version_id = 1, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_QLIST_V(fds, CprState, 1, vmstate_cpr_fd, CprFd, next), + VMSTATE_END_OF_LIST() + } +}; +/*************************************************************************/ + +static QEMUFile *cpr_state_file; + +QIOChannel *cpr_state_ioc(void) +{ + return qemu_file_get_ioc(cpr_state_file); +} + +static MigMode incoming_mode = MIG_MODE_NONE; + +MigMode cpr_get_incoming_mode(void) +{ + return incoming_mode; +} + +void cpr_set_incoming_mode(MigMode mode) +{ + incoming_mode = mode; +} + +bool cpr_is_incoming(void) +{ + return incoming_mode != MIG_MODE_NONE; +} + +int cpr_state_save(MigrationChannel *channel, Error **errp) +{ + int ret; + QEMUFile *f; + MigMode mode = migrate_mode(); + + trace_cpr_state_save(MigMode_str(mode)); + + if (mode == MIG_MODE_CPR_TRANSFER) { + g_assert(channel); + f = cpr_transfer_output(channel, errp); + } else { + return 0; + } + if (!f) { + return -1; + } + + qemu_put_be32(f, QEMU_CPR_FILE_MAGIC); + qemu_put_be32(f, QEMU_CPR_FILE_VERSION); + + ret = vmstate_save_state(f, &vmstate_cpr_state, &cpr_state, 0); + if (ret) { + error_setg(errp, "vmstate_save_state error %d", ret); + qemu_fclose(f); + return ret; + } + + /* + * Close the socket only partially so we can later detect when the other + * end closes by getting a HUP event. + */ + qemu_fflush(f); + qio_channel_shutdown(qemu_file_get_ioc(f), QIO_CHANNEL_SHUTDOWN_WRITE, + NULL); + cpr_state_file = f; + return 0; +} + +int cpr_state_load(MigrationChannel *channel, Error **errp) +{ + int ret; + uint32_t v; + QEMUFile *f; + MigMode mode = 0; + + if (channel) { + mode = MIG_MODE_CPR_TRANSFER; + cpr_set_incoming_mode(mode); + f = cpr_transfer_input(channel, errp); + } else { + return 0; + } + if (!f) { + return -1; + } + + trace_cpr_state_load(MigMode_str(mode)); + + v = qemu_get_be32(f); + if (v != QEMU_CPR_FILE_MAGIC) { + error_setg(errp, "Not a migration stream (bad magic %x)", v); + qemu_fclose(f); + return -EINVAL; + } + v = qemu_get_be32(f); + if (v != QEMU_CPR_FILE_VERSION) { + error_setg(errp, "Unsupported migration stream version %d", v); + qemu_fclose(f); + return -ENOTSUP; + } + + ret = vmstate_load_state(f, &vmstate_cpr_state, &cpr_state, 1); + if (ret) { + error_setg(errp, "vmstate_load_state error %d", ret); + qemu_fclose(f); + return ret; + } + + /* + * Let the caller decide when to close the socket (and generate a HUP event + * for the sending side). + */ + cpr_state_file = f; + + return ret; +} + +void cpr_state_close(void) +{ + if (cpr_state_file) { + qemu_fclose(cpr_state_file); + cpr_state_file = NULL; + } +} + +bool cpr_incoming_needed(void *opaque) +{ + MigMode mode = migrate_mode(); + return mode == MIG_MODE_CPR_TRANSFER; +} |