Restoring a 'fixed-ram' enabled migration stream would require reading from specific offsets in the file so add a helper to QEMUFile that uses the newly introduced qio_channel_file_preadv.
Signed-off-by: Nikolay Borisov <nbori...@suse.com> --- migration/qemu-file.c | 23 +++++++++++++++++++++++ migration/qemu-file.h | 1 + 2 files changed, 24 insertions(+) diff --git a/migration/qemu-file.c b/migration/qemu-file.c index 07ba1125e83f..73fffbdb9b7e 100644 --- a/migration/qemu-file.c +++ b/migration/qemu-file.c @@ -564,6 +564,29 @@ void qemu_put_buffer_at(QEMUFile *f, const uint8_t *buf, size_t buflen, off_t po return; } + +size_t qemu_get_buffer_at(QEMUFile *f, const uint8_t *buf, size_t buflen, off_t pos) +{ + Error *err = NULL; + struct iovec iov = { .iov_base = (char *)buf, .iov_len = buflen }; + ssize_t ret; + + if (f->last_error) { + return 0; + } + + ret = qio_channel_file_preadv(f->ioc, &iov, 1, pos, &err); + if (ret == -1) { + goto error; + } + + return (size_t)ret; + + error: + qemu_file_set_error_obj(f, -EIO, err); + return 0; +} + void qemu_set_offset(QEMUFile *f, off_t off, int whence) { Error *err = NULL; diff --git a/migration/qemu-file.h b/migration/qemu-file.h index 33cfc07b81d1..ab10c3ad7e42 100644 --- a/migration/qemu-file.h +++ b/migration/qemu-file.h @@ -151,6 +151,7 @@ void qemu_file_set_blocking(QEMUFile *f, bool block); void qemu_set_offset(QEMUFile *f, off_t off, int whence); off_t qemu_get_offset(QEMUFile *f); void qemu_put_buffer_at(QEMUFile *f, const uint8_t *buf, size_t buflen, off_t pos); +size_t qemu_get_buffer_at(QEMUFile *f, const uint8_t *buf, size_t buflen, off_t pos); void ram_control_before_iterate(QEMUFile *f, uint64_t flags); void ram_control_after_iterate(QEMUFile *f, uint64_t flags); -- 2.34.1