diff options
Diffstat (limited to 'hw/block/xen_blkif.h')
| -rw-r--r-- | hw/block/xen_blkif.h | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/hw/block/xen_blkif.h b/hw/block/xen_blkif.h index 711b692742..c68487cb31 100644 --- a/hw/block/xen_blkif.h +++ b/hw/block/xen_blkif.h @@ -85,8 +85,10 @@ static inline void blkif_get_x86_32_req(blkif_request_t *dst, blkif_x86_32_reque d->nr_sectors = s->nr_sectors; return; } - if (n > src->nr_segments) - n = src->nr_segments; + /* prevent the compiler from optimizing the code and using src->nr_segments instead */ + barrier(); + if (n > dst->nr_segments) + n = dst->nr_segments; for (i = 0; i < n; i++) dst->seg[i] = src->seg[i]; } @@ -106,8 +108,10 @@ static inline void blkif_get_x86_64_req(blkif_request_t *dst, blkif_x86_64_reque d->nr_sectors = s->nr_sectors; return; } - if (n > src->nr_segments) - n = src->nr_segments; + /* prevent the compiler from optimizing the code and using src->nr_segments instead */ + barrier(); + if (n > dst->nr_segments) + n = dst->nr_segments; for (i = 0; i < n; i++) dst->seg[i] = src->seg[i]; } |