diff --git a/migration/file.c b/migration/file.c index a903710f06..db870f2cf0 100644 --- a/migration/file.c +++ b/migration/file.c @@ -50,12 +50,31 @@ void file_cleanup_outgoing_migration(void) outgoing_args.fname = NULL; } +static void file_enable_direct_io(int *flags) +{ +#ifdef O_DIRECT + *flags |= O_DIRECT; +#else + /* it should have been rejected when setting the parameter */ + g_assert_not_reached(); +#endif +} + bool file_send_channel_create(gpointer opaque, Error **errp) { QIOChannelFile *ioc; int flags = O_WRONLY; bool ret = true; + if (migrate_direct_io()) { + /* + * Enable O_DIRECT for the secondary channels. These are used + * for sending ram pages and writes should be guaranteed to be + * aligned to at least page size. + */ + file_enable_direct_io(&flags); + } + ioc = qio_channel_file_new_path(outgoing_args.fname, flags, 0, errp); if (!ioc) { ret = false; @@ -117,21 +136,25 @@ static gboolean file_accept_incoming_migration(QIOChannel *ioc, return G_SOURCE_REMOVE; } -void file_create_incoming_channels(QIOChannel *ioc, Error **errp) +static void file_create_incoming_channels(QIOChannel *ioc, char *filename, + Error **errp) { - int i, fd, channels = 1; + int i, channels = 1; g_autofree QIOChannel **iocs = NULL; + int flags = O_RDONLY; if (migrate_multifd()) { channels += migrate_multifd_channels(); + if (migrate_direct_io()) { + file_enable_direct_io(&flags); + } } iocs = g_new0(QIOChannel *, channels); - fd = QIO_CHANNEL_FILE(ioc)->fd; iocs[0] = ioc; for (i = 1; i < channels; i++) { - QIOChannelFile *fioc = qio_channel_file_new_dupfd(fd, errp); + QIOChannelFile *fioc = qio_channel_file_new_path(filename, flags, 0, errp); if (!fioc) { while (i) { @@ -171,7 +194,7 @@ void file_start_incoming_migration(FileMigrationArgs *file_args, Error **errp) return; } - file_create_incoming_channels(QIO_CHANNEL(fioc), errp); + file_create_incoming_channels(QIO_CHANNEL(fioc), filename, errp); } int file_write_ramblock_iov(QIOChannel *ioc, const struct iovec *iov, diff --git a/migration/file.h b/migration/file.h index 7699c04677..9f71e87f74 100644 --- a/migration/file.h +++ b/migration/file.h @@ -20,7 +20,6 @@ void file_start_outgoing_migration(MigrationState *s, int file_parse_offset(char *filespec, uint64_t *offsetp, Error **errp); void file_cleanup_outgoing_migration(void); bool file_send_channel_create(gpointer opaque, Error **errp); -void file_create_incoming_channels(QIOChannel *ioc, Error **errp); int file_write_ramblock_iov(QIOChannel *ioc, const struct iovec *iov, int niov, RAMBlock *block, Error **errp); int multifd_file_recv_data(MultiFDRecvParams *p, Error **errp); diff --git a/migration/migration.c b/migration/migration.c index e1b269624c..e03c80b3aa 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -155,6 +155,16 @@ static bool migration_needs_seekable_channel(void) return migrate_mapped_ram(); } +static bool migration_needs_extra_fds(void) +{ + /* + * When doing direct-io, multifd requires two different, + * non-duplicated file descriptors so we can use one of them for + * unaligned IO. + */ + return migrate_multifd() && migrate_direct_io(); +} + static bool transport_supports_seeking(MigrationAddress *addr) { if (addr->transport == MIGRATION_ADDRESS_TYPE_FILE) { @@ -164,6 +174,12 @@ static bool transport_supports_seeking(MigrationAddress *addr) return false; } +static bool transport_supports_extra_fds(MigrationAddress *addr) +{ + /* file: works because QEMU can open it multiple times */ + return addr->transport == MIGRATION_ADDRESS_TYPE_FILE; +} + static bool migration_channels_and_transport_compatible(MigrationAddress *addr, Error **errp) @@ -180,6 +196,13 @@ migration_channels_and_transport_compatible(MigrationAddress *addr, return false; } + if (migration_needs_extra_fds() && + !transport_supports_extra_fds(addr)) { + error_setg(errp, + "Migration requires a transport that allows for extra fds (e.g. file)"); + return false; + } + return true; }