Add a bunch of auxiliarry methods and a feature flag to work with SEEKABLE channels. Currently the only channel considered seekable is QIOChannelFile. Also add a bunch of helper functions to QEMUFile that can make use of this channel feature. All of this is in prepration for supporting 'fixed-ram' migration stream feature.
Signed-off-by: Nikolay Borisov <nbori...@suse.com> --- include/io/channel.h | 1 + include/migration/qemu-file-types.h | 2 + io/channel-file.c | 5 +++ migration/qemu-file.c | 59 +++++++++++++++++++++++++++++ migration/qemu-file.h | 3 ++ 5 files changed, 70 insertions(+) diff --git a/include/io/channel.h b/include/io/channel.h index c680ee748021..4fc37c78e68c 100644 --- a/include/io/channel.h +++ b/include/io/channel.h @@ -41,6 +41,7 @@ enum QIOChannelFeature { QIO_CHANNEL_FEATURE_SHUTDOWN, QIO_CHANNEL_FEATURE_LISTEN, QIO_CHANNEL_FEATURE_WRITE_ZERO_COPY, + QIO_CHANNEL_FEATURE_SEEKABLE, }; diff --git a/include/migration/qemu-file-types.h b/include/migration/qemu-file-types.h index 2867e3da84ab..eb0325ee8687 100644 --- a/include/migration/qemu-file-types.h +++ b/include/migration/qemu-file-types.h @@ -50,6 +50,8 @@ unsigned int qemu_get_be16(QEMUFile *f); unsigned int qemu_get_be32(QEMUFile *f); uint64_t qemu_get_be64(QEMUFile *f); +bool qemu_file_is_seekable(QEMUFile *f); + static inline void qemu_put_be64s(QEMUFile *f, const uint64_t *pv) { qemu_put_be64(f, *pv); diff --git a/io/channel-file.c b/io/channel-file.c index da17d0a11ba7..d84a6737f2f7 100644 --- a/io/channel-file.c +++ b/io/channel-file.c @@ -35,6 +35,7 @@ qio_channel_file_new_fd(int fd) ioc->fd = fd; + qio_channel_set_feature(QIO_CHANNEL(ioc), QIO_CHANNEL_FEATURE_SEEKABLE); trace_qio_channel_file_new_fd(ioc, fd); return ioc; @@ -59,6 +60,10 @@ qio_channel_file_new_path(const char *path, return NULL; } + if (lseek(ioc->fd, 0, SEEK_CUR) != (off_t)-1) { + qio_channel_set_feature(QIO_CHANNEL(ioc), QIO_CHANNEL_FEATURE_SEEKABLE); + } + trace_qio_channel_file_new_path(ioc, path, flags, mode, ioc->fd); return ioc; diff --git a/migration/qemu-file.c b/migration/qemu-file.c index 4f400c2e5265..07ba1125e83f 100644 --- a/migration/qemu-file.c +++ b/migration/qemu-file.c @@ -30,6 +30,7 @@ #include "qemu-file.h" #include "trace.h" #include "qapi/error.h" +#include "io/channel-file.h" #define IO_BUF_SIZE 32768 #define MAX_IOV_SIZE MIN_CONST(IOV_MAX, 64) @@ -260,6 +261,10 @@ static void qemu_iovec_release_ram(QEMUFile *f) memset(f->may_free, 0, sizeof(f->may_free)); } +bool qemu_file_is_seekable(QEMUFile *f) +{ + return qio_channel_has_feature(f->ioc, QIO_CHANNEL_FEATURE_SEEKABLE); +} /** * Flushes QEMUFile buffer @@ -538,6 +543,60 @@ void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, size_t size) } } +void qemu_put_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 }; + + if (f->last_error) { + return; + } + + qemu_fflush(f); + + if (qio_channel_file_pwritev(f->ioc, &iov, 1, pos, &err) == (off_t)-1) + goto error; + + return; + + error: + qemu_file_set_error_obj(f, -EIO, err); + return; +} + +void qemu_set_offset(QEMUFile *f, off_t off, int whence) +{ + Error *err = NULL; + off_t ret; + + qemu_fflush(f); + + if (!qemu_file_is_writable(f)) { + f->buf_index = 0; + f->buf_size = 0; + } + + ret = qio_channel_io_seek(f->ioc, off, whence, &err); + if (ret == (off_t)-1) { + qemu_file_set_error_obj(f, -EIO, err); + } +} + +off_t qemu_get_offset(QEMUFile *f) +{ + Error *err = NULL; + off_t ret; + + qemu_fflush(f); + + ret = qio_channel_io_seek(f->ioc, 0, SEEK_CUR, &err); + if (ret == (off_t)-1) { + qemu_file_set_error_obj(f, -EIO, err); + } + return ret; +} + + void qemu_put_byte(QEMUFile *f, int v) { if (f->last_error) { diff --git a/migration/qemu-file.h b/migration/qemu-file.h index fa13d04d787c..33cfc07b81d1 100644 --- a/migration/qemu-file.h +++ b/migration/qemu-file.h @@ -148,6 +148,9 @@ int qemu_file_shutdown(QEMUFile *f); QEMUFile *qemu_file_get_return_path(QEMUFile *f); void qemu_fflush(QEMUFile *f); 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); void ram_control_before_iterate(QEMUFile *f, uint64_t flags); void ram_control_after_iterate(QEMUFile *f, uint64_t flags); -- 2.34.1