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[Qemu-devel] [PULL 20/22] util: add qemu_iovec_is_zero
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PULL 20/22] util: add qemu_iovec_is_zero |
Date: |
Mon, 19 May 2014 16:22:38 +0200 |
From: Peter Lieven <address@hidden>
Signed-off-by: Peter Lieven <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
include/qemu-common.h | 1 +
util/iov.c | 21 +++++++++++++++++++++
2 files changed, 22 insertions(+)
diff --git a/include/qemu-common.h b/include/qemu-common.h
index 3f3fd60..66ceceb 100644
--- a/include/qemu-common.h
+++ b/include/qemu-common.h
@@ -318,6 +318,7 @@ void qemu_iovec_concat(QEMUIOVector *dst,
void qemu_iovec_concat_iov(QEMUIOVector *dst,
struct iovec *src_iov, unsigned int src_cnt,
size_t soffset, size_t sbytes);
+bool qemu_iovec_is_zero(QEMUIOVector *qiov);
void qemu_iovec_destroy(QEMUIOVector *qiov);
void qemu_iovec_reset(QEMUIOVector *qiov);
size_t qemu_iovec_to_buf(QEMUIOVector *qiov, size_t offset,
diff --git a/util/iov.c b/util/iov.c
index 6569b5a..49f8838 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);
--
1.8.3.1
- [Qemu-devel] [PULL 10/22] qemu-iotests: Fix blkdebug in VM drive in 030, (continued)
- [Qemu-devel] [PULL 10/22] qemu-iotests: Fix blkdebug in VM drive in 030, Kevin Wolf, 2014/05/19
- [Qemu-devel] [PULL 14/22] curl: Add usage documentation, Kevin Wolf, 2014/05/19
- [Qemu-devel] [PULL 12/22] curl: Remove broken parsing of options from url, Kevin Wolf, 2014/05/19
- [Qemu-devel] [PULL 11/22] curl: Fix build when curl_multi_socket_action isn't available, Kevin Wolf, 2014/05/19
- [Qemu-devel] [PULL 15/22] qcow1: Make padding in the header explicit, Kevin Wolf, 2014/05/19
- [Qemu-devel] [PULL 16/22] qcow1: Check maximum cluster size, Kevin Wolf, 2014/05/19
- [Qemu-devel] [PULL 13/22] curl: Add sslverify option, Kevin Wolf, 2014/05/19
- [Qemu-devel] [PULL 17/22] qcow1: Validate L2 table size (CVE-2014-0222), Kevin Wolf, 2014/05/19
- [Qemu-devel] [PULL 19/22] qcow1: Stricter backing file length check, Kevin Wolf, 2014/05/19
- [Qemu-devel] [PULL 18/22] qcow1: Validate image size (CVE-2014-0223), Kevin Wolf, 2014/05/19
- [Qemu-devel] [PULL 20/22] util: add qemu_iovec_is_zero,
Kevin Wolf <=
- [Qemu-devel] [PULL 21/22] blockdev: add a function to parse enum ids from strings, Kevin Wolf, 2014/05/19
- [Qemu-devel] [PULL 22/22] block: optimize zero writes with bdrv_write_zeroes, Kevin Wolf, 2014/05/19
- Re: [Qemu-devel] [PULL 00/22] Block patches, Peter Maydell, 2014/05/22