vpc: Handle failure for potentially large allocations

Some code in the block layer makes potentially huge allocations. Failure
is not completely unexpected there, so avoid aborting qemu and handle
out-of-memory situations gracefully.

This patch addresses the allocations in the vpc block driver.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>

diff --git a/block/vpc.c b/block/vpc.c
index 96903441b89b802b8e6b1125009bce5202a77c57..055efc42d21cdfcb649a7c55f086489c0e355a0f 100644 (file)
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -269,7 +269,11 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags,
             goto fail;
         }
 
-        s->pagetable = qemu_blockalign(bs, s->max_table_entries * 4);
+        s->pagetable = qemu_try_blockalign(bs->file, s->max_table_entries * 4);
+        if (s->pagetable == NULL) {
+            ret = -ENOMEM;
+            goto fail;
+        }
 
         s->bat_offset = be64_to_cpu(dyndisk_header->table_offset);