diff --git a/migration/file.c b/migration/file.c index 0a65c43fdd..cf5b1bf365 100644 --- a/migration/file.c +++ b/migration/file.c @@ -6,6 +6,8 @@ */ #include "qemu/osdep.h" +#include "qemu/cutils.h" +#include "qapi/error.h" #include "channel.h" #include "file.h" #include "migration.h" @@ -13,14 +15,41 @@ #include "io/channel-util.h" #include "trace.h" -void file_start_outgoing_migration(MigrationState *s, const char *filename, +#define OFFSET_OPTION ",offset=" + +/* Remove the offset option from @filespec and return it in @offsetp. */ + +static int file_parse_offset(char *filespec, uint64_t *offsetp, Error **errp) +{ + char *option = strstr(filespec, OFFSET_OPTION); + int ret; + + if (option) { + *option = 0; + option += sizeof(OFFSET_OPTION) - 1; + ret = qemu_strtosz(option, NULL, offsetp); + if (ret) { + error_setg_errno(errp, -ret, "file URI has bad offset %s", option); + return -1; + } + } + return 0; +} + +void file_start_outgoing_migration(MigrationState *s, const char *filespec, Error **errp) { + g_autofree char *filename = g_strdup(filespec); g_autoptr(QIOChannelFile) fioc = NULL; + uint64_t offset = 0; QIOChannel *ioc; trace_migration_file_outgoing(filename); + if (file_parse_offset(filename, &offset, errp)) { + return; + } + fioc = qio_channel_file_new_path(filename, O_CREAT | O_WRONLY | O_TRUNC, 0600, errp); if (!fioc) { @@ -28,6 +57,9 @@ void file_start_outgoing_migration(MigrationState *s, const char *filename, } ioc = QIO_CHANNEL(fioc); + if (offset && qio_channel_io_seek(ioc, offset, SEEK_SET, errp) < 0) { + return; + } qio_channel_set_name(ioc, "migration-file-outgoing"); migration_channel_connect(s, ioc, NULL, NULL); } @@ -41,19 +73,28 @@ static gboolean file_accept_incoming_migration(QIOChannel *ioc, return G_SOURCE_REMOVE; } -void file_start_incoming_migration(const char *filename, Error **errp) +void file_start_incoming_migration(const char *filespec, Error **errp) { + g_autofree char *filename = g_strdup(filespec); QIOChannelFile *fioc = NULL; + uint64_t offset = 0; QIOChannel *ioc; trace_migration_file_incoming(filename); + if (file_parse_offset(filename, &offset, errp)) { + return; + } + fioc = qio_channel_file_new_path(filename, O_RDONLY, 0, errp); if (!fioc) { return; } ioc = QIO_CHANNEL(fioc); + if (offset && qio_channel_io_seek(ioc, offset, SEEK_SET, errp) < 0) { + return; + } qio_channel_set_name(QIO_CHANNEL(ioc), "migration-file-incoming"); qio_channel_add_watch_full(ioc, G_IO_IN, file_accept_incoming_migration, diff --git a/qemu-options.hx b/qemu-options.hx index 93e638c097..840b83d237 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4706,7 +4706,7 @@ DEF("incoming", HAS_ARG, QEMU_OPTION_incoming, \ " prepare for incoming migration, listen on\n" \ " specified protocol and socket address\n" \ "-incoming fd:fd\n" \ - "-incoming file:filename\n" \ + "-incoming file:filename[,offset=offset]\n" \ "-incoming exec:cmdline\n" \ " accept incoming migration on given file descriptor\n" \ " or from given external command\n" \ @@ -4725,8 +4725,9 @@ SRST ``-incoming fd:fd`` Accept incoming migration from a given file descriptor. -``-incoming file:filename`` - Accept incoming migration from a given file. +``-incoming file:filename[,offset=offset]`` + Accept incoming migration from a given file starting at offset. + offset allows the common size suffixes, or a 0x prefix, but not both. ``-incoming exec:cmdline`` Accept incoming migration as an output from specified external