Re: [PATCH] NVMe: init nvme queue before enabling irq

From: Sagi Grimberg
Date: Wed Jan 20 2016 - 04:08:01 EST

During reset process, the nvme_dev->bar (ioremapped) may change,
so nvmeq->q_db shall be also updated by nvme_init_queue().

Currently nvmeq irq is enabled before queue init, so a spurious
interrupt triggered nvme_process_cq may access nvmeq->q_db just
before it is updated, this could cause kernel panic.

Signed-off-by: Wenbo Wang <>
Reviewed-by: Wenwei Tao <wenwei.tao@xxxxxxxxxxxx>

This patch makes sense to me.

drivers/nvme/host/pci.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index f5c0e26..df55f28 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1590,11 +1590,17 @@ static int nvme_create_queue(struct nvme_queue *nvmeq, int qid)
if (result < 0)
goto release_cq;

+ /*
+ * Init queue door bell ioremap address before enabling irq, if not,
+ * a spurious interrupt triggered nvme_process_cq may access invalid
+ * address
+ */

Not sure we need an explicit comment on the fix here. But I don't
mind keeping it.

+ nvme_init_queue(nvmeq, qid);

I think that this makes the duplication in nvme_alloc_queue redundant.
Can you remove it?

Other then that, looks good to me,

Reviewed-by: Sagi Grimberg <sagig@xxxxxxxxxxxx>