[Qemu-devel] [PATCH 1/2] migration: update index field when delete or qsort RDMALocalBlock

[Lidong Chen <jemmy858585@gmail.com>]

rdma_delete_block function deletes RDMALocalBlock base on index field,
but not update the index field. So when next time invoke rdma_delete_block,
it will not work correctly.

If start and cancel migration repeatedly, some RDMALocalBlock not invoke
ibv_dereg_mr to decrease kernel mm_struct vmpin. When vmpin is large than
max locked memory limitation, ibv_reg_mr will failed, and migration can not
start successfully again.

Signed-off-by: Lidong Chen <lidongchen@tencent.com>
---
 migration/rdma.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/migration/rdma.c b/migration/rdma.c
index ed9cfb1..0dd4033 100644
--- a/migration/rdma.c
+++ b/migration/rdma.c
@@ -713,6 +713,9 @@ static int rdma_delete_block(RDMAContext *rdma, RDMALocalBlock *block)
             memcpy(local->block + block->index, old + (block->index + 1),
                 sizeof(RDMALocalBlock) *
                     (local->nb_blocks - (block->index + 1)));
+            for (x = block->index; x < local->nb_blocks - 1; x++) {
+                local->block[x].index--;
+            }
         }
     } else {
         assert(block == local->block);
@@ -3398,6 +3401,10 @@ static int qemu_rdma_registration_handle(QEMUFile *f, void *opaque)
             qsort(rdma->local_ram_blocks.block,
                   rdma->local_ram_blocks.nb_blocks,
                   sizeof(RDMALocalBlock), dest_ram_sort_func);
+            for (i = 0; i < local->nb_blocks; i++) {
+                local->block[i].index = i;
+            }
+
             if (rdma->pin_all) {
                 ret = qemu_rdma_reg_whole_ram_blocks(rdma);
                 if (ret) {
-- 
1.8.3.1