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authoraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>2009-01-22 16:59:20 +0000
committeraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>2009-01-22 16:59:20 +0000
commit44e3ee8a2aaee5df49cd440446fee4525144255f (patch)
tree450cf688ca2c46221c9e4447da0bbabde0398b29 /cutils.c
parentba223c29da480b40b38678c66636ee9910973a47 (diff)
I/O vector helpers (Avi Kivity)
In general, it is not possible to predict the size of of an I/O vector since a contiguous guest region may map to a disconiguous host region. Add some helpers to manage I/O vector growth. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6396 c046a42c-6fe2-441c-8c8c-71466251a162
Diffstat (limited to 'cutils.c')
-rw-r--r--cutils.c47
1 files changed, 47 insertions, 0 deletions
diff --git a/cutils.c b/cutils.c
index 9617e083c..80a7a1d8f 100644
--- a/cutils.c
+++ b/cutils.c
@@ -101,3 +101,50 @@ int qemu_fls(int i)
{
return 32 - clz32(i);
}
+
+/* io vectors */
+
+void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint)
+{
+ qiov->iov = qemu_malloc(alloc_hint * sizeof(struct iovec));
+ qiov->niov = 0;
+ qiov->nalloc = alloc_hint;
+}
+
+void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len)
+{
+ if (qiov->niov == qiov->nalloc) {
+ qiov->nalloc = 2 * qiov->nalloc + 1;
+ qiov->iov = qemu_realloc(qiov->iov, qiov->nalloc * sizeof(struct iovec));
+ }
+ qiov->iov[qiov->niov].iov_base = base;
+ qiov->iov[qiov->niov].iov_len = len;
+ ++qiov->niov;
+}
+
+void qemu_iovec_destroy(QEMUIOVector *qiov)
+{
+ qemu_free(qiov->iov);
+}
+
+void qemu_iovec_to_buffer(QEMUIOVector *qiov, void *buf)
+{
+ uint8_t *p = (uint8_t *)buf;
+ int i;
+
+ for (i = 0; i < qiov->niov; ++i) {
+ memcpy(p, qiov->iov[i].iov_base, qiov->iov[i].iov_len);
+ p += qiov->iov[i].iov_len;
+ }
+}
+
+void qemu_iovec_from_buffer(QEMUIOVector *qiov, const void *buf)
+{
+ const uint8_t *p = (const uint8_t *)buf;
+ int i;
+
+ for (i = 0; i < qiov->niov; ++i) {
+ memcpy(qiov->iov[i].iov_base, p, qiov->iov[i].iov_len);
+ p += qiov->iov[i].iov_len;
+ }
+}