diff options
Diffstat (limited to 'dma-helpers.c')
| -rw-r--r-- | dma-helpers.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/dma-helpers.c b/dma-helpers.c index e8a26e81e1..2a77b5a9cb 100644 --- a/dma-helpers.c +++ b/dma-helpers.c @@ -13,6 +13,8 @@ #include "trace-root.h" #include "qemu/thread.h" #include "qemu/main-loop.h" +#include "sysemu/cpus.h" +#include "qemu/range.h" /* #define DEBUG_IOMMU */ @@ -142,6 +144,26 @@ static void dma_blk_cb(void *opaque, int ret) cur_addr = dbs->sg->sg[dbs->sg_cur_index].base + dbs->sg_cur_byte; cur_len = dbs->sg->sg[dbs->sg_cur_index].len - dbs->sg_cur_byte; mem = dma_memory_map(dbs->sg->as, cur_addr, &cur_len, dbs->dir); + /* + * Make reads deterministic in icount mode. Windows sometimes issues + * disk read requests with overlapping SGs. It leads + * to non-determinism, because resulting buffer contents may be mixed + * from several sectors. This code splits all SGs into several + * groups. SGs in every group do not overlap. + */ + if (mem && use_icount && dbs->dir == DMA_DIRECTION_FROM_DEVICE) { + int i; + for (i = 0 ; i < dbs->iov.niov ; ++i) { + if (ranges_overlap((intptr_t)dbs->iov.iov[i].iov_base, + dbs->iov.iov[i].iov_len, (intptr_t)mem, + cur_len)) { + dma_memory_unmap(dbs->sg->as, mem, cur_len, + dbs->dir, cur_len); + mem = NULL; + break; + } + } + } if (!mem) break; qemu_iovec_add(&dbs->iov, mem, cur_len); |