| Message ID | 1727725244-105198-3-git-send-email-steven.sistare@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Live update: cpr-transfer | expand |
On Mon, Sep 30, 2024 at 12:40:33PM -0700, Steve Sistare wrote: > CPR must save state that is needed after QEMU is restarted, when devices > are realized. Thus the extra state cannot be saved in the migration stream, > as objects must already exist before that stream can be loaded. Instead, > define auxilliary state structures and vmstate descriptions, not associated > with any registered object, and serialize the aux state to a cpr-specific > stream in cpr_state_save. Deserialize in cpr_state_load after QEMU > restarts, before devices are realized. > > Provide accessors for clients to register file descriptors for saving. > The mechanism for passing the fd's to the new process will be specific > to each migration mode, and added in subsequent patches. > > Signed-off-by: Steve Sistare <steven.sistare@oracle.com> > Reviewed-by: Fabiano Rosas <farosas@suse.de> Only two trivial comments below. > --- > include/migration/cpr.h | 26 ++++++ > migration/cpr.c | 217 ++++++++++++++++++++++++++++++++++++++++++++++++ > migration/meson.build | 1 + > migration/migration.c | 6 ++ > migration/trace-events | 5 ++ > system/vl.c | 7 ++ > 6 files changed, 262 insertions(+) > create mode 100644 include/migration/cpr.h > create mode 100644 migration/cpr.c > > diff --git a/include/migration/cpr.h b/include/migration/cpr.h > new file mode 100644 > index 0000000..e7b898b > --- /dev/null > +++ b/include/migration/cpr.h > @@ -0,0 +1,26 @@ > +/* > + * 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. > + */ > + > +#ifndef MIGRATION_CPR_H > +#define MIGRATION_CPR_H > + > +#define QEMU_CPR_FILE_MAGIC 0x51435052 > +#define QEMU_CPR_FILE_VERSION 0x00000001 > + > +typedef int (*cpr_walk_fd_cb)(int fd); > +void cpr_save_fd(const char *name, int id, int fd); > +void cpr_delete_fd(const char *name, int id); > +int cpr_find_fd(const char *name, int id); > +int cpr_walk_fd(cpr_walk_fd_cb cb); > +void cpr_resave_fd(const char *name, int id, int fd); > + > +int cpr_state_save(Error **errp); > +int cpr_state_load(Error **errp); > +void cpr_state_close(void); > +struct QIOChannel *cpr_state_ioc(void); > + > +#endif > diff --git a/migration/cpr.c b/migration/cpr.c > new file mode 100644 > index 0000000..e50fc75 > --- /dev/null > +++ b/migration/cpr.c > @@ -0,0 +1,217 @@ > +/* > + * 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/qemu-file.h" > +#include "migration/savevm.h" > +#include "migration/vmstate.h" > +#include "sysemu/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_INT32(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; > +} > + > +int cpr_walk_fd(cpr_walk_fd_cb cb) > +{ > + CprFd *elem; > + > + QLIST_FOREACH(elem, &cpr_state.fds, next) { > + if (elem->fd >= 0 && cb(elem->fd)) { > + return 1; > + } > + } > + return 0; > +} > + > +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); > + } > +} I remember I commented this, maybe not.. cpr_walk_fd() and cpr_resave_fd() are not used in this series. Suggest introduce them only when they're used. > +/*************************************************************************/ > +#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); > +} > + > +int cpr_state_save(Error **errp) > +{ > + int ret; > + QEMUFile *f; > + > + /* set f based on mode in a later patch in this series */ > + return 0; > + > + 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); What happens if we send everything and close immediately? I didn't see how this cached file is used later throughout the whole series. Is it used in some follow up series? > + cpr_state_file = f; > + return 0; > +} > + > +int cpr_state_load(Error **errp) > +{ > + int ret; > + uint32_t v; > + QEMUFile *f; > + > + /* set f based on mode in a later patch in this series */ > + return 0; > + > + 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; > + } > +} > diff --git a/migration/meson.build b/migration/meson.build > index 66d3de8..e5f4211 100644 > --- a/migration/meson.build > +++ b/migration/meson.build > @@ -13,6 +13,7 @@ system_ss.add(files( > 'block-dirty-bitmap.c', > 'channel.c', > 'channel-block.c', > + 'cpr.c', > 'dirtyrate.c', > 'exec.c', > 'fd.c', > diff --git a/migration/migration.c b/migration/migration.c > index ae2be31..834b0a2 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -27,6 +27,7 @@ > #include "sysemu/cpu-throttle.h" > #include "rdma.h" > #include "ram.h" > +#include "migration/cpr.h" > #include "migration/global_state.h" > #include "migration/misc.h" > #include "migration.h" > @@ -2123,6 +2124,10 @@ void qmp_migrate(const char *uri, bool has_channels, > } > } > > + if (cpr_state_save(&local_err)) { > + goto out; > + } > + > if (addr->transport == MIGRATION_ADDRESS_TYPE_SOCKET) { > SocketAddress *saddr = &addr->u.socket; > if (saddr->type == SOCKET_ADDRESS_TYPE_INET || > @@ -2147,6 +2152,7 @@ void qmp_migrate(const char *uri, bool has_channels, > MIGRATION_STATUS_FAILED); > } > > +out: > if (local_err) { > if (!resume_requested) { > yank_unregister_instance(MIGRATION_YANK_INSTANCE); > diff --git a/migration/trace-events b/migration/trace-events > index c65902f..5356fb5 100644 > --- a/migration/trace-events > +++ b/migration/trace-events > @@ -341,6 +341,11 @@ colo_receive_message(const char *msg) "Receive '%s' message" > # colo-failover.c > colo_failover_set_state(const char *new_state) "new state %s" > > +# cpr.c > +cpr_save_fd(const char *name, int id, int fd) "%s, id %d, fd %d" > +cpr_delete_fd(const char *name, int id) "%s, id %d" > +cpr_find_fd(const char *name, int id, int fd) "%s, id %d returns %d" > + > # block-dirty-bitmap.c > send_bitmap_header_enter(void) "" > send_bitmap_bits(uint32_t flags, uint64_t start_sector, uint32_t nr_sectors, uint64_t data_size) "flags: 0x%x, start_sector: %" PRIu64 ", nr_sectors: %" PRIu32 ", data_size: %" PRIu64 > diff --git a/system/vl.c b/system/vl.c > index 752a1da..565d932 100644 > --- a/system/vl.c > +++ b/system/vl.c > @@ -77,6 +77,7 @@ > #include "hw/block/block.h" > #include "hw/i386/x86.h" > #include "hw/i386/pc.h" > +#include "migration/cpr.h" > #include "migration/misc.h" > #include "migration/snapshot.h" > #include "sysemu/tpm.h" > @@ -3720,6 +3721,12 @@ void qemu_init(int argc, char **argv) > > qemu_create_machine(machine_opts_dict); > > + /* > + * Load incoming CPR state before any devices are created, because it > + * contains file descriptors that are needed in device initialization code. > + */ > + cpr_state_load(&error_fatal); > + > suspend_mux_open(); > > qemu_disable_default_devices(); > -- > 1.8.3.1 >
On 10/7/2024 10:14 AM, Peter Xu wrote: > On Mon, Sep 30, 2024 at 12:40:33PM -0700, Steve Sistare wrote: >> CPR must save state that is needed after QEMU is restarted, when devices >> are realized. Thus the extra state cannot be saved in the migration stream, >> as objects must already exist before that stream can be loaded. Instead, >> define auxilliary state structures and vmstate descriptions, not associated >> with any registered object, and serialize the aux state to a cpr-specific >> stream in cpr_state_save. Deserialize in cpr_state_load after QEMU >> restarts, before devices are realized. >> >> Provide accessors for clients to register file descriptors for saving. >> The mechanism for passing the fd's to the new process will be specific >> to each migration mode, and added in subsequent patches. >> >> Signed-off-by: Steve Sistare <steven.sistare@oracle.com> >> Reviewed-by: Fabiano Rosas <farosas@suse.de> > > Only two trivial comments below. > >> --- >> include/migration/cpr.h | 26 ++++++ >> migration/cpr.c | 217 ++++++++++++++++++++++++++++++++++++++++++++++++ >> migration/meson.build | 1 + >> migration/migration.c | 6 ++ >> migration/trace-events | 5 ++ >> system/vl.c | 7 ++ >> 6 files changed, 262 insertions(+) >> create mode 100644 include/migration/cpr.h >> create mode 100644 migration/cpr.c >> >> diff --git a/include/migration/cpr.h b/include/migration/cpr.h >> new file mode 100644 >> index 0000000..e7b898b >> --- /dev/null >> +++ b/include/migration/cpr.h >> @@ -0,0 +1,26 @@ >> +/* >> + * 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. >> + */ >> + >> +#ifndef MIGRATION_CPR_H >> +#define MIGRATION_CPR_H >> + >> +#define QEMU_CPR_FILE_MAGIC 0x51435052 >> +#define QEMU_CPR_FILE_VERSION 0x00000001 >> + >> +typedef int (*cpr_walk_fd_cb)(int fd); >> +void cpr_save_fd(const char *name, int id, int fd); >> +void cpr_delete_fd(const char *name, int id); >> +int cpr_find_fd(const char *name, int id); >> +int cpr_walk_fd(cpr_walk_fd_cb cb); >> +void cpr_resave_fd(const char *name, int id, int fd); >> + >> +int cpr_state_save(Error **errp); >> +int cpr_state_load(Error **errp); >> +void cpr_state_close(void); >> +struct QIOChannel *cpr_state_ioc(void); >> + >> +#endif >> diff --git a/migration/cpr.c b/migration/cpr.c >> new file mode 100644 >> index 0000000..e50fc75 >> --- /dev/null >> +++ b/migration/cpr.c >> @@ -0,0 +1,217 @@ >> +/* >> + * 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/qemu-file.h" >> +#include "migration/savevm.h" >> +#include "migration/vmstate.h" >> +#include "sysemu/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_INT32(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; >> +} >> + >> +int cpr_walk_fd(cpr_walk_fd_cb cb) >> +{ >> + CprFd *elem; >> + >> + QLIST_FOREACH(elem, &cpr_state.fds, next) { >> + if (elem->fd >= 0 && cb(elem->fd)) { >> + return 1; >> + } >> + } >> + return 0; >> +} >> + >> +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); >> + } >> +} > > I remember I commented this, maybe not.. cpr_walk_fd() and cpr_resave_fd() > are not used in this series. Suggest introduce them only when they're > used. Thanks, you probably did. I just edited my tree, so I will not forget again. >> +/*************************************************************************/ >> +#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); >> +} >> + >> +int cpr_state_save(Error **errp) >> +{ >> + int ret; >> + QEMUFile *f; >> + >> + /* set f based on mode in a later patch in this series */ >> + return 0; >> + >> + 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); > > What happens if we send everything and close immediately? > > I didn't see how this cached file is used later throughout the whole > series. Is it used in some follow up series? The complete usage and rationale is in the last patch, "migration: cpr-transfer mode" - Steve >> + cpr_state_file = f; >> + return 0; >> +} >> + >> +int cpr_state_load(Error **errp) >> +{ >> + int ret; >> + uint32_t v; >> + QEMUFile *f; >> + >> + /* set f based on mode in a later patch in this series */ >> + return 0; >> + >> + 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; >> + } >> +} >> diff --git a/migration/meson.build b/migration/meson.build >> index 66d3de8..e5f4211 100644 >> --- a/migration/meson.build >> +++ b/migration/meson.build >> @@ -13,6 +13,7 @@ system_ss.add(files( >> 'block-dirty-bitmap.c', >> 'channel.c', >> 'channel-block.c', >> + 'cpr.c', >> 'dirtyrate.c', >> 'exec.c', >> 'fd.c', >> diff --git a/migration/migration.c b/migration/migration.c >> index ae2be31..834b0a2 100644 >> --- a/migration/migration.c >> +++ b/migration/migration.c >> @@ -27,6 +27,7 @@ >> #include "sysemu/cpu-throttle.h" >> #include "rdma.h" >> #include "ram.h" >> +#include "migration/cpr.h" >> #include "migration/global_state.h" >> #include "migration/misc.h" >> #include "migration.h" >> @@ -2123,6 +2124,10 @@ void qmp_migrate(const char *uri, bool has_channels, >> } >> } >> >> + if (cpr_state_save(&local_err)) { >> + goto out; >> + } >> + >> if (addr->transport == MIGRATION_ADDRESS_TYPE_SOCKET) { >> SocketAddress *saddr = &addr->u.socket; >> if (saddr->type == SOCKET_ADDRESS_TYPE_INET || >> @@ -2147,6 +2152,7 @@ void qmp_migrate(const char *uri, bool has_channels, >> MIGRATION_STATUS_FAILED); >> } >> >> +out: >> if (local_err) { >> if (!resume_requested) { >> yank_unregister_instance(MIGRATION_YANK_INSTANCE); >> diff --git a/migration/trace-events b/migration/trace-events >> index c65902f..5356fb5 100644 >> --- a/migration/trace-events >> +++ b/migration/trace-events >> @@ -341,6 +341,11 @@ colo_receive_message(const char *msg) "Receive '%s' message" >> # colo-failover.c >> colo_failover_set_state(const char *new_state) "new state %s" >> >> +# cpr.c >> +cpr_save_fd(const char *name, int id, int fd) "%s, id %d, fd %d" >> +cpr_delete_fd(const char *name, int id) "%s, id %d" >> +cpr_find_fd(const char *name, int id, int fd) "%s, id %d returns %d" >> + >> # block-dirty-bitmap.c >> send_bitmap_header_enter(void) "" >> send_bitmap_bits(uint32_t flags, uint64_t start_sector, uint32_t nr_sectors, uint64_t data_size) "flags: 0x%x, start_sector: %" PRIu64 ", nr_sectors: %" PRIu32 ", data_size: %" PRIu64 >> diff --git a/system/vl.c b/system/vl.c >> index 752a1da..565d932 100644 >> --- a/system/vl.c >> +++ b/system/vl.c >> @@ -77,6 +77,7 @@ >> #include "hw/block/block.h" >> #include "hw/i386/x86.h" >> #include "hw/i386/pc.h" >> +#include "migration/cpr.h" >> #include "migration/misc.h" >> #include "migration/snapshot.h" >> #include "sysemu/tpm.h" >> @@ -3720,6 +3721,12 @@ void qemu_init(int argc, char **argv) >> >> qemu_create_machine(machine_opts_dict); >> >> + /* >> + * Load incoming CPR state before any devices are created, because it >> + * contains file descriptors that are needed in device initialization code. >> + */ >> + cpr_state_load(&error_fatal); >> + >> suspend_mux_open(); >> >> qemu_disable_default_devices(); >> -- >> 1.8.3.1 >> >
diff --git a/include/migration/cpr.h b/include/migration/cpr.h new file mode 100644 index 0000000..e7b898b --- /dev/null +++ b/include/migration/cpr.h @@ -0,0 +1,26 @@ +/* + * 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. + */ + +#ifndef MIGRATION_CPR_H +#define MIGRATION_CPR_H + +#define QEMU_CPR_FILE_MAGIC 0x51435052 +#define QEMU_CPR_FILE_VERSION 0x00000001 + +typedef int (*cpr_walk_fd_cb)(int fd); +void cpr_save_fd(const char *name, int id, int fd); +void cpr_delete_fd(const char *name, int id); +int cpr_find_fd(const char *name, int id); +int cpr_walk_fd(cpr_walk_fd_cb cb); +void cpr_resave_fd(const char *name, int id, int fd); + +int cpr_state_save(Error **errp); +int cpr_state_load(Error **errp); +void cpr_state_close(void); +struct QIOChannel *cpr_state_ioc(void); + +#endif diff --git a/migration/cpr.c b/migration/cpr.c new file mode 100644 index 0000000..e50fc75 --- /dev/null +++ b/migration/cpr.c @@ -0,0 +1,217 @@ +/* + * 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/qemu-file.h" +#include "migration/savevm.h" +#include "migration/vmstate.h" +#include "sysemu/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_INT32(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; +} + +int cpr_walk_fd(cpr_walk_fd_cb cb) +{ + CprFd *elem; + + QLIST_FOREACH(elem, &cpr_state.fds, next) { + if (elem->fd >= 0 && cb(elem->fd)) { + return 1; + } + } + return 0; +} + +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); + } +} +/*************************************************************************/ +#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); +} + +int cpr_state_save(Error **errp) +{ + int ret; + QEMUFile *f; + + /* set f based on mode in a later patch in this series */ + return 0; + + 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(Error **errp) +{ + int ret; + uint32_t v; + QEMUFile *f; + + /* set f based on mode in a later patch in this series */ + return 0; + + 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; + } +} diff --git a/migration/meson.build b/migration/meson.build index 66d3de8..e5f4211 100644 --- a/migration/meson.build +++ b/migration/meson.build @@ -13,6 +13,7 @@ system_ss.add(files( 'block-dirty-bitmap.c', 'channel.c', 'channel-block.c', + 'cpr.c', 'dirtyrate.c', 'exec.c', 'fd.c', diff --git a/migration/migration.c b/migration/migration.c index ae2be31..834b0a2 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -27,6 +27,7 @@ #include "sysemu/cpu-throttle.h" #include "rdma.h" #include "ram.h" +#include "migration/cpr.h" #include "migration/global_state.h" #include "migration/misc.h" #include "migration.h" @@ -2123,6 +2124,10 @@ void qmp_migrate(const char *uri, bool has_channels, } } + if (cpr_state_save(&local_err)) { + goto out; + } + if (addr->transport == MIGRATION_ADDRESS_TYPE_SOCKET) { SocketAddress *saddr = &addr->u.socket; if (saddr->type == SOCKET_ADDRESS_TYPE_INET || @@ -2147,6 +2152,7 @@ void qmp_migrate(const char *uri, bool has_channels, MIGRATION_STATUS_FAILED); } +out: if (local_err) { if (!resume_requested) { yank_unregister_instance(MIGRATION_YANK_INSTANCE); diff --git a/migration/trace-events b/migration/trace-events index c65902f..5356fb5 100644 --- a/migration/trace-events +++ b/migration/trace-events @@ -341,6 +341,11 @@ colo_receive_message(const char *msg) "Receive '%s' message" # colo-failover.c colo_failover_set_state(const char *new_state) "new state %s" +# cpr.c +cpr_save_fd(const char *name, int id, int fd) "%s, id %d, fd %d" +cpr_delete_fd(const char *name, int id) "%s, id %d" +cpr_find_fd(const char *name, int id, int fd) "%s, id %d returns %d" + # block-dirty-bitmap.c send_bitmap_header_enter(void) "" send_bitmap_bits(uint32_t flags, uint64_t start_sector, uint32_t nr_sectors, uint64_t data_size) "flags: 0x%x, start_sector: %" PRIu64 ", nr_sectors: %" PRIu32 ", data_size: %" PRIu64 diff --git a/system/vl.c b/system/vl.c index 752a1da..565d932 100644 --- a/system/vl.c +++ b/system/vl.c @@ -77,6 +77,7 @@ #include "hw/block/block.h" #include "hw/i386/x86.h" #include "hw/i386/pc.h" +#include "migration/cpr.h" #include "migration/misc.h" #include "migration/snapshot.h" #include "sysemu/tpm.h" @@ -3720,6 +3721,12 @@ void qemu_init(int argc, char **argv) qemu_create_machine(machine_opts_dict); + /* + * Load incoming CPR state before any devices are created, because it + * contains file descriptors that are needed in device initialization code. + */ + cpr_state_load(&error_fatal); + suspend_mux_open(); qemu_disable_default_devices();