diff options
| author |   Don Dugger <n0ano@n0ano.com> | 2016-06-03 03:33:22 +0000 |
|---|---|---|
| committer |   Gerrit Code Review <gerrit@172.30.200.206> | 2016-06-03 03:33:23 +0000 |
| commit | da27230f80795d0028333713f036d44c53cb0e68 (patch) | |
| tree | b3d379eaf000adf72b36cb01cdf4d79c3e3f064c /qemu/hw/block/xen_blkif.h | |
| parent | 0e68cb048bb8aadb14675f5d4286d8ab2fc35449 (diff) | |
| parent | 437fd90c0250dee670290f9b714253671a990160 (diff) | |
Merge "These changes are the raw update to qemu-2.6."
Diffstat (limited to 'qemu/hw/block/xen_blkif.h')
| -rw-r--r-- | qemu/hw/block/xen_blkif.h | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/qemu/hw/block/xen_blkif.h b/qemu/hw/block/xen_blkif.h index 711b69274..c68487cb3 100644 --- a/qemu/hw/block/xen_blkif.h +++ b/qemu/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]; } |