diff options
Diffstat (limited to 'util/iov.c')
-rw-r--r-- | util/iov.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/util/iov.c b/util/iov.c index 6569b5aae1..49f88388f8 100644 --- a/util/iov.c +++ b/util/iov.c @@ -335,6 +335,27 @@ void qemu_iovec_concat(QEMUIOVector *dst, qemu_iovec_concat_iov(dst, src->iov, src->niov, soffset, sbytes); } +/* + * Check if the contents of the iovecs are all zero + */ +bool qemu_iovec_is_zero(QEMUIOVector *qiov) +{ + int i; + for (i = 0; i < qiov->niov; i++) { + size_t offs = QEMU_ALIGN_DOWN(qiov->iov[i].iov_len, 4 * sizeof(long)); + uint8_t *ptr = qiov->iov[i].iov_base; + if (offs && !buffer_is_zero(qiov->iov[i].iov_base, offs)) { + return false; + } + for (; offs < qiov->iov[i].iov_len; offs++) { + if (ptr[offs]) { + return false; + } + } + } + return true; +} + void qemu_iovec_destroy(QEMUIOVector *qiov) { assert(qiov->nalloc != -1); |