Introduce two new QEMUSizedBuffer APIs which will be used by COLO to buffer VM state: One is qsb_put_buffer(), which put the content of a given QEMUSizedBuffer into QEMUFile, this is used to send buffered VM state to secondary. Another is qsb_fill_buffer(), read 'size' bytes of data from the file into qsb, this is used to get VM state from socket into a buffer.
Signed-off-by: zhanghailiang <zhang.zhanghaili...@huawei.com> Signed-off-by: Li Zhijian <lizhij...@cn.fujitsu.com> Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com> --- v11: - size_t'ify these two help functions (Dave's suggestion) --- include/migration/qemu-file.h | 3 ++- migration/qemu-file-buf.c | 61 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 63 insertions(+), 1 deletion(-) diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h index b5d08d2..ca6a582 100644 --- a/include/migration/qemu-file.h +++ b/include/migration/qemu-file.h @@ -150,7 +150,8 @@ ssize_t qsb_get_buffer(const QEMUSizedBuffer *, off_t start, size_t count, uint8_t *buf); ssize_t qsb_write_at(QEMUSizedBuffer *qsb, const uint8_t *buf, off_t pos, size_t count); - +void qsb_put_buffer(QEMUFile *f, QEMUSizedBuffer *qsb, size_t size); +size_t qsb_fill_buffer(QEMUSizedBuffer *qsb, QEMUFile *f, size_t size); /* * For use on files opened with qemu_bufopen diff --git a/migration/qemu-file-buf.c b/migration/qemu-file-buf.c index 7b8e78e..7801780 100644 --- a/migration/qemu-file-buf.c +++ b/migration/qemu-file-buf.c @@ -367,6 +367,67 @@ ssize_t qsb_write_at(QEMUSizedBuffer *qsb, const uint8_t *source, return count; } +/** + * Put the content of a given QEMUSizedBuffer into QEMUFile. + * + * @f: A QEMUFile + * @qsb: A QEMUSizedBuffer + * @size: size of content to write + */ +void qsb_put_buffer(QEMUFile *f, QEMUSizedBuffer *qsb, size_t size) +{ + size_t l; + int i; + + for (i = 0; i < qsb->n_iov && size > 0; i++) { + l = MIN(qsb->iov[i].iov_len, size); + qemu_put_buffer(f, qsb->iov[i].iov_base, l); + size -= l; + } +} + +/* + * Read 'size' bytes of data from the file into qsb. + * always fill from pos 0 and used after qsb_create(). + * + * It will return size bytes unless there was an error, in which case it will + * return as many as it managed to read (assuming blocking fd's which + * all current QEMUFile are) + */ +size_t qsb_fill_buffer(QEMUSizedBuffer *qsb, QEMUFile *f, size_t size) +{ + ssize_t rc = qsb_grow(qsb, size); + ssize_t pending = size; + int i; + uint8_t *buf = NULL; + + qsb->used = 0; + + if (rc < 0) { + return rc; + } + + for (i = 0; i < qsb->n_iov && pending > 0; i++) { + size_t doneone = 0; + /* read until iov full */ + while (doneone < qsb->iov[i].iov_len && pending > 0) { + size_t readone = 0; + + buf = qsb->iov[i].iov_base; + readone = qemu_get_buffer(f, buf, + MIN(qsb->iov[i].iov_len - doneone, pending)); + if (readone == 0) { + return qsb->used; + } + buf += readone; + doneone += readone; + pending -= readone; + qsb->used += readone; + } + } + return qsb->used; +} + typedef struct QEMUBuffer { QEMUSizedBuffer *qsb; QEMUFile *file; -- 1.8.3.1