diff options
Diffstat (limited to 'migration/rdma.c')
| -rw-r--r-- | migration/rdma.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/migration/rdma.c b/migration/rdma.c index eb80431aae..2a3c7889b9 100644 --- a/migration/rdma.c +++ b/migration/rdma.c @@ -1133,6 +1133,32 @@ static bool rdma_support_odp(struct ibv_context *dev) return false; } +/* + * ibv_advise_mr to avoid RNR NAK error as far as possible. + * The responder mr registering with ODP will sent RNR NAK back to + * the requester in the face of the page fault. + */ +static void qemu_rdma_advise_prefetch_mr(struct ibv_pd *pd, uint64_t addr, + uint32_t len, uint32_t lkey, + const char *name, bool wr) +{ +#ifdef HAVE_IBV_ADVISE_MR + int ret; + int advice = wr ? IBV_ADVISE_MR_ADVICE_PREFETCH_WRITE : + IBV_ADVISE_MR_ADVICE_PREFETCH; + struct ibv_sge sg_list = {.lkey = lkey, .addr = addr, .length = len}; + + ret = ibv_advise_mr(pd, advice, + IBV_ADVISE_MR_FLAG_FLUSH, &sg_list, 1); + /* ignore the error */ + if (ret) { + trace_qemu_rdma_advise_mr(name, len, addr, strerror(errno)); + } else { + trace_qemu_rdma_advise_mr(name, len, addr, "successed"); + } +#endif +} + static int qemu_rdma_reg_whole_ram_blocks(RDMAContext *rdma) { int i; @@ -1156,6 +1182,15 @@ static int qemu_rdma_reg_whole_ram_blocks(RDMAContext *rdma) local->block[i].local_host_addr, local->block[i].length, access); trace_qemu_rdma_register_odp_mr(local->block[i].block_name); + + if (local->block[i].mr) { + qemu_rdma_advise_prefetch_mr(rdma->pd, + (uintptr_t)local->block[i].local_host_addr, + local->block[i].length, + local->block[i].mr->lkey, + local->block[i].block_name, + true); + } } if (!local->block[i].mr) { @@ -1255,6 +1290,13 @@ static int qemu_rdma_register_and_get_keys(RDMAContext *rdma, /* register ODP mr */ block->pmr[chunk] = ibv_reg_mr(rdma->pd, chunk_start, len, access); trace_qemu_rdma_register_odp_mr(block->block_name); + + if (block->pmr[chunk]) { + qemu_rdma_advise_prefetch_mr(rdma->pd, (uintptr_t)chunk_start, + len, block->pmr[chunk]->lkey, + block->block_name, rkey); + + } } } if (!block->pmr[chunk]) { |