From: Igor Druzhinin <igor.druzhinin@citrix.com>
Date: Tue, 6 Nov 2018 12:16:55 +0000 (+0000)
Subject: nvme: call blk_drain in NVMe reset code to avoid lockups
X-Git-Tag: v3.1.0-rc3~13^2~7
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6bf7463615752934d7221e5be9820d9da45ab2de;p=thirdparty%2Fqemu.git

nvme: call blk_drain in NVMe reset code to avoid lockups

When blk_flush called in NVMe reset path S/C queues are already freed
which means that re-entering AIO handling loop having some IO requests
unfinished will lockup or crash as their SG structures being potentially
reused. Call blk_drain before freeing the queues to avoid this nasty
scenario.

Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index d0226e7fdcd..28d284346dd 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -797,6 +797,8 @@ static void nvme_clear_ctrl(NvmeCtrl *n)
 {
     int i;
 
+    blk_drain(n->conf.blk);
+
     for (i = 0; i < n->num_queues; i++) {
         if (n->sq[i] != NULL) {
             nvme_free_sq(n->sq[i], n);