@@ -106,8 +106,8 @@ int is_windows_drive(const char *filename)
size_t bdrv_opt_mem_align(BlockDriverState *bs)
{
if (!bs || !bs->drv) {
- /* 4k should be on the safe side */
- return 4096;
+ /* page size or 4k (hdd sector size) should be on the safe side */
+ return MAX(4096, getpagesize());
}
return bs->bl.opt_mem_alignment;
@@ -116,8 +116,8 @@ size_t bdrv_opt_mem_align(BlockDriverState *bs)
size_t bdrv_min_mem_align(BlockDriverState *bs)
{
if (!bs || !bs->drv) {
- /* 4k should be on the safe side */
- return 4096;
+ /* page size or 4k (hdd sector size) should be on the safe side */
+ return MAX(4096, getpagesize());
}
return bs->bl.min_mem_alignment;
@@ -205,7 +205,7 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error **errp)
bs->bl.opt_mem_alignment = bs->file->bl.opt_mem_alignment;
} else {
bs->bl.min_mem_alignment = 512;
- bs->bl.opt_mem_alignment = 512;
+ bs->bl.opt_mem_alignment = getpagesize();
}
if (bs->backing_hd) {
@@ -301,6 +301,7 @@ static void raw_probe_alignment(BlockDriverState *bs, int fd, Error **errp)
{
BDRVRawState *s = bs->opaque;
char *buf;
+ size_t max_align = MAX(MAX_BLOCKSIZE, getpagesize());
/* For /dev/sg devices the alignment is not really used.
With buffered I/O, we don't have any restrictions. */
@@ -330,9 +331,9 @@ static void raw_probe_alignment(BlockDriverState *bs, int fd, Error **errp)
/* If we could not get the sizes so far, we can only guess them */
if (!s->buf_align) {
size_t align;
- buf = qemu_memalign(MAX_BLOCKSIZE, 2 * MAX_BLOCKSIZE);
- for (align = 512; align <= MAX_BLOCKSIZE; align <<= 1) {
- if (raw_is_io_aligned(fd, buf + align, MAX_BLOCKSIZE)) {
+ buf = qemu_memalign(max_align, 2 * max_align);
+ for (align = 512; align <= max_align; align <<= 1) {
+ if (raw_is_io_aligned(fd, buf + align, max_align)) {
s->buf_align = align;
break;
}
@@ -342,8 +343,8 @@ static void raw_probe_alignment(BlockDriverState *bs, int fd, Error **errp)
if (!bs->request_alignment) {
size_t align;
- buf = qemu_memalign(s->buf_align, MAX_BLOCKSIZE);
- for (align = 512; align <= MAX_BLOCKSIZE; align <<= 1) {
+ buf = qemu_memalign(s->buf_align, max_align);
+ for (align = 512; align <= max_align; align <<= 1) {
if (raw_is_io_aligned(fd, buf, align)) {
bs->request_alignment = align;
break;
@@ -726,7 +727,7 @@ static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
raw_probe_alignment(bs, s->fd, errp);
bs->bl.min_mem_alignment = s->buf_align;
- bs->bl.opt_mem_alignment = s->buf_align;
+ bs->bl.opt_mem_alignment = MAX(s->buf_align, getpagesize());
}
static int check_for_dasd(int fd)