From 58f423fbd5f7f435e8dc56dfa565b043d20d1e1b Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 9 Jul 2014 19:17:30 +0200 Subject: dma-helpers: Fix too long qiov If the size of the scatter/gather list isn't a multiple of 512, the number of sectors for the block layer request is rounded down, resulting in a qiov that doesn't match the request length. Truncate the qiov to the new length of the request. This fixes the IDE qtest case /x86_64/ide/bmdma/short_prdt. Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake --- util/iov.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'util') diff --git a/util/iov.c b/util/iov.c index 2b4f46da75..24566c8789 100644 --- a/util/iov.c +++ b/util/iov.c @@ -550,3 +550,16 @@ size_t iov_discard_back(struct iovec *iov, unsigned int *iov_cnt, return total; } + +void qemu_iovec_discard_back(QEMUIOVector *qiov, size_t bytes) +{ + size_t total; + unsigned int niov = qiov->niov; + + assert(qiov->size >= bytes); + total = iov_discard_back(qiov->iov, &niov, bytes); + assert(total == bytes); + + qiov->niov = niov; + qiov->size -= bytes; +} -- cgit v1.2.1