| Message ID | 20221229110345.12480-7-avihaih@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vfio/migration: Implement VFIO migration protocol v2 | expand |
On 12/29/22 12:03, Avihai Horon wrote: > Add new function qemu_file_get_to_fd() that allows reading data from > QEMUFile and writing it straight into a given fd. > > This will be used later in VFIO migration code. > > Signed-off-by: Avihai Horon <avihaih@nvidia.com> > Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> > --- > migration/qemu-file.h | 1 + > migration/qemu-file.c | 34 ++++++++++++++++++++++++++++++++++ > 2 files changed, 35 insertions(+) > > diff --git a/migration/qemu-file.h b/migration/qemu-file.h > index fa13d04d78..9d0155a2a1 100644 > --- a/migration/qemu-file.h > +++ b/migration/qemu-file.h > @@ -148,6 +148,7 @@ 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); > +int qemu_file_get_to_fd(QEMUFile *f, int fd, size_t size); > > void ram_control_before_iterate(QEMUFile *f, uint64_t flags); > void ram_control_after_iterate(QEMUFile *f, uint64_t flags); > diff --git a/migration/qemu-file.c b/migration/qemu-file.c > index 2d5f74ffc2..79303c9d34 100644 > --- a/migration/qemu-file.c > +++ b/migration/qemu-file.c > @@ -940,3 +940,37 @@ QIOChannel *qemu_file_get_ioc(QEMUFile *file) > { > return file->ioc; > } > + > +/* > + * Read size bytes from QEMUFile f and write them to fd. > + */ > +int qemu_file_get_to_fd(QEMUFile *f, int fd, size_t size) > +{ > + while (size) { > + size_t pending = f->buf_size - f->buf_index; > + ssize_t rc; > + > + if (!pending) { > + rc = qemu_fill_buffer(f); > + if (rc < 0) { > + return rc; > + } > + if (rc == 0) { > + return -1; Given the call stack, -1 would be interpreted as EPERM. May be EIO instead ? C. > + } > + continue; > + } > + > + rc = write(fd, f->buf + f->buf_index, MIN(pending, size)); > + if (rc < 0) { > + return rc; > + } > + if (rc == 0) { > + return -1; > + } > + f->buf_index += rc; > + size -= rc; > + } > + > + return 0; > +}
On 09/01/2023 13:20, Cédric Le Goater wrote: > External email: Use caution opening links or attachments > > > On 12/29/22 12:03, Avihai Horon wrote: >> Add new function qemu_file_get_to_fd() that allows reading data from >> QEMUFile and writing it straight into a given fd. >> >> This will be used later in VFIO migration code. >> >> Signed-off-by: Avihai Horon <avihaih@nvidia.com> >> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> >> --- >> migration/qemu-file.h | 1 + >> migration/qemu-file.c | 34 ++++++++++++++++++++++++++++++++++ >> 2 files changed, 35 insertions(+) >> >> diff --git a/migration/qemu-file.h b/migration/qemu-file.h >> index fa13d04d78..9d0155a2a1 100644 >> --- a/migration/qemu-file.h >> +++ b/migration/qemu-file.h >> @@ -148,6 +148,7 @@ 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); >> +int qemu_file_get_to_fd(QEMUFile *f, int fd, size_t size); >> >> void ram_control_before_iterate(QEMUFile *f, uint64_t flags); >> void ram_control_after_iterate(QEMUFile *f, uint64_t flags); >> diff --git a/migration/qemu-file.c b/migration/qemu-file.c >> index 2d5f74ffc2..79303c9d34 100644 >> --- a/migration/qemu-file.c >> +++ b/migration/qemu-file.c >> @@ -940,3 +940,37 @@ QIOChannel *qemu_file_get_ioc(QEMUFile *file) >> { >> return file->ioc; >> } >> + >> +/* >> + * Read size bytes from QEMUFile f and write them to fd. >> + */ >> +int qemu_file_get_to_fd(QEMUFile *f, int fd, size_t size) >> +{ >> + while (size) { >> + size_t pending = f->buf_size - f->buf_index; >> + ssize_t rc; >> + >> + if (!pending) { >> + rc = qemu_fill_buffer(f); >> + if (rc < 0) { >> + return rc; >> + } >> + if (rc == 0) { >> + return -1; > > Given the call stack, -1 would be interpreted as EPERM. May be EIO > instead ? > Sure. I will also change write (down below) to return -errno instead of rc on error. > C. > >> + } >> + continue; >> + } >> + >> + rc = write(fd, f->buf + f->buf_index, MIN(pending, size)); >> + if (rc < 0) { >> + return rc; >> + } >> + if (rc == 0) { >> + return -1; >> + } >> + f->buf_index += rc; >> + size -= rc; >> + } >> + >> + return 0; >> +} >
diff --git a/migration/qemu-file.h b/migration/qemu-file.h index fa13d04d78..9d0155a2a1 100644 --- a/migration/qemu-file.h +++ b/migration/qemu-file.h @@ -148,6 +148,7 @@ 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); +int qemu_file_get_to_fd(QEMUFile *f, int fd, size_t size); void ram_control_before_iterate(QEMUFile *f, uint64_t flags); void ram_control_after_iterate(QEMUFile *f, uint64_t flags); diff --git a/migration/qemu-file.c b/migration/qemu-file.c index 2d5f74ffc2..79303c9d34 100644 --- a/migration/qemu-file.c +++ b/migration/qemu-file.c @@ -940,3 +940,37 @@ QIOChannel *qemu_file_get_ioc(QEMUFile *file) { return file->ioc; } + +/* + * Read size bytes from QEMUFile f and write them to fd. + */ +int qemu_file_get_to_fd(QEMUFile *f, int fd, size_t size) +{ + while (size) { + size_t pending = f->buf_size - f->buf_index; + ssize_t rc; + + if (!pending) { + rc = qemu_fill_buffer(f); + if (rc < 0) { + return rc; + } + if (rc == 0) { + return -1; + } + continue; + } + + rc = write(fd, f->buf + f->buf_index, MIN(pending, size)); + if (rc < 0) { + return rc; + } + if (rc == 0) { + return -1; + } + f->buf_index += rc; + size -= rc; + } + + return 0; +}