| Message ID | 20240220224138.24759-21-farosas@suse.de |
|---|---|
| State | New |
| Headers | show |
| Series | migration: File based migration with multifd and fixed-ram | expand |
On Tue, Feb 20, 2024 at 07:41:24PM -0300, Fabiano Rosas wrote: > Allow multifd to open file-backed channels. This will be used when > enabling the fixed-ram migration stream format which expects a > seekable transport. > > The QIOChannel read and write methods will use the preadv/pwritev > versions which don't update the file offset at each call so we can > reuse the fd without re-opening for every channel. > > Contrary to the socket migration, the file migration doesn't need an > asynchronous channel creation process, so expose > multifd_channel_connect() and call it directly. > > Note that this is just setup code and multifd cannot yet make use of > the file channels. > > Signed-off-by: Fabiano Rosas <farosas@suse.de> > --- > migration/file.c | 40 ++++++++++++++++++++++++++++++++++++++-- > migration/file.h | 5 +++++ > migration/multifd.c | 27 ++++++++++++++++++++++----- > migration/multifd.h | 2 ++ > 4 files changed, 67 insertions(+), 7 deletions(-) > > diff --git a/migration/file.c b/migration/file.c > index 22d052a71f..ac9f6ae40a 100644 > --- a/migration/file.c > +++ b/migration/file.c > @@ -12,12 +12,17 @@ > #include "channel.h" > #include "file.h" > #include "migration.h" > +#include "multifd.h" > #include "io/channel-file.h" > #include "io/channel-util.h" > #include "trace.h" > > #define OFFSET_OPTION ",offset=" > > +static struct FileOutgoingArgs { > + char *fname; > +} outgoing_args; > + > /* Remove the offset option from @filespec and return it in @offsetp. */ > > int file_parse_offset(char *filespec, uint64_t *offsetp, Error **errp) > @@ -37,6 +42,34 @@ int file_parse_offset(char *filespec, uint64_t *offsetp, Error **errp) > return 0; > } > > +int file_send_channel_destroy(QIOChannel *ioc) > +{ > + if (ioc) { > + qio_channel_close(ioc, NULL); > + } > + g_free(outgoing_args.fname); > + outgoing_args.fname = NULL; > + > + return 0; > +} > + > +bool file_send_channel_create(gpointer opaque, Error **errp) > +{ > + QIOChannelFile *ioc; > + int flags = O_WRONLY; > + > + ioc = qio_channel_file_new_path(outgoing_args.fname, flags, 0, errp); > + if (!ioc) { > + return false; > + } > + > + if (!multifd_channel_connect(opaque, QIO_CHANNEL(ioc), errp)) { > + return false; > + } > + > + return true; > +} > + > void file_start_outgoing_migration(MigrationState *s, > FileMigrationArgs *file_args, Error **errp) > { > @@ -44,15 +77,18 @@ void file_start_outgoing_migration(MigrationState *s, > g_autofree char *filename = g_strdup(file_args->filename); > uint64_t offset = file_args->offset; > QIOChannel *ioc; > + int flags = O_CREAT | O_TRUNC | O_WRONLY; > + mode_t mode = 0660; > > trace_migration_file_outgoing(filename); > > - fioc = qio_channel_file_new_path(filename, O_CREAT | O_WRONLY | O_TRUNC, > - 0600, errp); > + fioc = qio_channel_file_new_path(filename, flags, mode, errp); This change seems irrelevant, could be squashed into the previous patch when introduced? > if (!fioc) { > return; > } > > + outgoing_args.fname = g_strdup(filename); > + > ioc = QIO_CHANNEL(fioc); > if (offset && qio_channel_io_seek(ioc, offset, SEEK_SET, errp) < 0) { > return; > diff --git a/migration/file.h b/migration/file.h > index 37d6a08bfc..90794b494b 100644 > --- a/migration/file.h > +++ b/migration/file.h > @@ -9,10 +9,15 @@ > #define QEMU_MIGRATION_FILE_H > > #include "qapi/qapi-types-migration.h" > +#include "io/task.h" > +#include "channel.h" > > void file_start_incoming_migration(FileMigrationArgs *file_args, Error **errp); > > void file_start_outgoing_migration(MigrationState *s, > FileMigrationArgs *file_args, Error **errp); > int file_parse_offset(char *filespec, uint64_t *offsetp, Error **errp); > + > +bool file_send_channel_create(gpointer opaque, Error **errp); > +int file_send_channel_destroy(QIOChannel *ioc); > #endif > diff --git a/migration/multifd.c b/migration/multifd.c > index 45a0c7aaa8..507b497d52 100644 > --- a/migration/multifd.c > +++ b/migration/multifd.c > @@ -17,6 +17,7 @@ > #include "exec/ramblock.h" > #include "qemu/error-report.h" > #include "qapi/error.h" > +#include "file.h" > #include "ram.h" > #include "migration.h" > #include "migration-stats.h" > @@ -28,6 +29,7 @@ > #include "threadinfo.h" > #include "options.h" > #include "qemu/yank.h" > +#include "io/channel-file.h" > #include "io/channel-socket.h" > #include "yank_functions.h" > > @@ -680,6 +682,9 @@ static void multifd_send_terminate_threads(void) > > static int multifd_send_channel_destroy(QIOChannel *send) > { > + if (!multifd_use_packets()) { > + return file_send_channel_destroy(send); > + } > return socket_send_channel_destroy(send); > } > > @@ -959,9 +964,8 @@ static bool multifd_tls_channel_connect(MultiFDSendParams *p, > return true; > } > > -static bool multifd_channel_connect(MultiFDSendParams *p, > - QIOChannel *ioc, > - Error **errp) > +bool multifd_channel_connect(MultiFDSendParams *p, QIOChannel *ioc, > + Error **errp) > { > qio_channel_set_delay(ioc, false); > > @@ -1031,9 +1035,14 @@ out: > error_free(local_err); > } > > -static void multifd_new_send_channel_create(gpointer opaque) > +static bool multifd_new_send_channel_create(gpointer opaque, Error **errp) > { > + if (!multifd_use_packets()) { > + return file_send_channel_create(opaque, errp); > + } > + > socket_send_channel_create(multifd_new_send_channel_async, opaque); > + return true; > } > > bool multifd_send_setup(void) > @@ -1082,7 +1091,15 @@ bool multifd_send_setup(void) > p->page_size = qemu_target_page_size(); > p->page_count = page_count; > p->write_flags = 0; > - multifd_new_send_channel_create(p); > + > + if (!multifd_new_send_channel_create(p, &local_err)) { > + /* > + * File channel creation is synchronous, we don't need the > + * semaphore below, it's safe to return now. > + */ > + assert(migrate_fixed_ram()); This comment and assert() is slightly confusing to me. Drop them? IMHO it's always safe to directly return here, the channels_created sem will be destroyed later anyway so the number shouldn't matter. And as I commented in the other email, IMHO it's cleaner we also post that sem in file_send_channel_create(). > + return -1; > + } > } > > if (use_packets) { > diff --git a/migration/multifd.h b/migration/multifd.h > index 19188815a3..135f6ed098 100644 > --- a/migration/multifd.h > +++ b/migration/multifd.h > @@ -228,5 +228,7 @@ static inline void multifd_send_prepare_header(MultiFDSendParams *p) > p->iovs_num++; > } > > +bool multifd_channel_connect(MultiFDSendParams *p, QIOChannel *ioc, > + Error **errp); > > #endif > -- > 2.35.3 >
On Tue, Feb 20, 2024 at 07:41:24PM -0300, Fabiano Rosas wrote: > +int file_send_channel_destroy(QIOChannel *ioc) > +{ > + if (ioc) { > + qio_channel_close(ioc, NULL); > + } > + g_free(outgoing_args.fname); > + outgoing_args.fname = NULL; Ah another thing: we may want to have file_cleanup_outgoing_migration() from the 1st day if possible.. https://lore.kernel.org/all/20240222095301.171137-5-peterx@redhat.com/ The other one was already in my queue, so feel free to rebase to migration-next directly if before the next pull (I'll remember to push soon; now it is in -staging). Thanks,
diff --git a/migration/file.c b/migration/file.c index 22d052a71f..ac9f6ae40a 100644 --- a/migration/file.c +++ b/migration/file.c @@ -12,12 +12,17 @@ #include "channel.h" #include "file.h" #include "migration.h" +#include "multifd.h" #include "io/channel-file.h" #include "io/channel-util.h" #include "trace.h" #define OFFSET_OPTION ",offset=" +static struct FileOutgoingArgs { + char *fname; +} outgoing_args; + /* Remove the offset option from @filespec and return it in @offsetp. */ int file_parse_offset(char *filespec, uint64_t *offsetp, Error **errp) @@ -37,6 +42,34 @@ int file_parse_offset(char *filespec, uint64_t *offsetp, Error **errp) return 0; } +int file_send_channel_destroy(QIOChannel *ioc) +{ + if (ioc) { + qio_channel_close(ioc, NULL); + } + g_free(outgoing_args.fname); + outgoing_args.fname = NULL; + + return 0; +} + +bool file_send_channel_create(gpointer opaque, Error **errp) +{ + QIOChannelFile *ioc; + int flags = O_WRONLY; + + ioc = qio_channel_file_new_path(outgoing_args.fname, flags, 0, errp); + if (!ioc) { + return false; + } + + if (!multifd_channel_connect(opaque, QIO_CHANNEL(ioc), errp)) { + return false; + } + + return true; +} + void file_start_outgoing_migration(MigrationState *s, FileMigrationArgs *file_args, Error **errp) { @@ -44,15 +77,18 @@ void file_start_outgoing_migration(MigrationState *s, g_autofree char *filename = g_strdup(file_args->filename); uint64_t offset = file_args->offset; QIOChannel *ioc; + int flags = O_CREAT | O_TRUNC | O_WRONLY; + mode_t mode = 0660; trace_migration_file_outgoing(filename); - fioc = qio_channel_file_new_path(filename, O_CREAT | O_WRONLY | O_TRUNC, - 0600, errp); + fioc = qio_channel_file_new_path(filename, flags, mode, errp); if (!fioc) { return; } + outgoing_args.fname = g_strdup(filename); + ioc = QIO_CHANNEL(fioc); if (offset && qio_channel_io_seek(ioc, offset, SEEK_SET, errp) < 0) { return; diff --git a/migration/file.h b/migration/file.h index 37d6a08bfc..90794b494b 100644 --- a/migration/file.h +++ b/migration/file.h @@ -9,10 +9,15 @@ #define QEMU_MIGRATION_FILE_H #include "qapi/qapi-types-migration.h" +#include "io/task.h" +#include "channel.h" void file_start_incoming_migration(FileMigrationArgs *file_args, Error **errp); void file_start_outgoing_migration(MigrationState *s, FileMigrationArgs *file_args, Error **errp); int file_parse_offset(char *filespec, uint64_t *offsetp, Error **errp); + +bool file_send_channel_create(gpointer opaque, Error **errp); +int file_send_channel_destroy(QIOChannel *ioc); #endif diff --git a/migration/multifd.c b/migration/multifd.c index 45a0c7aaa8..507b497d52 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -17,6 +17,7 @@ #include "exec/ramblock.h" #include "qemu/error-report.h" #include "qapi/error.h" +#include "file.h" #include "ram.h" #include "migration.h" #include "migration-stats.h" @@ -28,6 +29,7 @@ #include "threadinfo.h" #include "options.h" #include "qemu/yank.h" +#include "io/channel-file.h" #include "io/channel-socket.h" #include "yank_functions.h" @@ -680,6 +682,9 @@ static void multifd_send_terminate_threads(void) static int multifd_send_channel_destroy(QIOChannel *send) { + if (!multifd_use_packets()) { + return file_send_channel_destroy(send); + } return socket_send_channel_destroy(send); } @@ -959,9 +964,8 @@ static bool multifd_tls_channel_connect(MultiFDSendParams *p, return true; } -static bool multifd_channel_connect(MultiFDSendParams *p, - QIOChannel *ioc, - Error **errp) +bool multifd_channel_connect(MultiFDSendParams *p, QIOChannel *ioc, + Error **errp) { qio_channel_set_delay(ioc, false); @@ -1031,9 +1035,14 @@ out: error_free(local_err); } -static void multifd_new_send_channel_create(gpointer opaque) +static bool multifd_new_send_channel_create(gpointer opaque, Error **errp) { + if (!multifd_use_packets()) { + return file_send_channel_create(opaque, errp); + } + socket_send_channel_create(multifd_new_send_channel_async, opaque); + return true; } bool multifd_send_setup(void) @@ -1082,7 +1091,15 @@ bool multifd_send_setup(void) p->page_size = qemu_target_page_size(); p->page_count = page_count; p->write_flags = 0; - multifd_new_send_channel_create(p); + + if (!multifd_new_send_channel_create(p, &local_err)) { + /* + * File channel creation is synchronous, we don't need the + * semaphore below, it's safe to return now. + */ + assert(migrate_fixed_ram()); + return -1; + } } if (use_packets) { diff --git a/migration/multifd.h b/migration/multifd.h index 19188815a3..135f6ed098 100644 --- a/migration/multifd.h +++ b/migration/multifd.h @@ -228,5 +228,7 @@ static inline void multifd_send_prepare_header(MultiFDSendParams *p) p->iovs_num++; } +bool multifd_channel_connect(MultiFDSendParams *p, QIOChannel *ioc, + Error **errp); #endif
Allow multifd to open file-backed channels. This will be used when enabling the fixed-ram migration stream format which expects a seekable transport. The QIOChannel read and write methods will use the preadv/pwritev versions which don't update the file offset at each call so we can reuse the fd without re-opening for every channel. Contrary to the socket migration, the file migration doesn't need an asynchronous channel creation process, so expose multifd_channel_connect() and call it directly. Note that this is just setup code and multifd cannot yet make use of the file channels. Signed-off-by: Fabiano Rosas <farosas@suse.de> --- migration/file.c | 40 ++++++++++++++++++++++++++++++++++++++-- migration/file.h | 5 +++++ migration/multifd.c | 27 ++++++++++++++++++++++----- migration/multifd.h | 2 ++ 4 files changed, 67 insertions(+), 7 deletions(-)