diff options
| author | Dan Aloni <dan@kernelim.com> | 2017-05-28 16:06:49 +0300 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2017-08-29 16:54:40 +0100 |
| commit | cdd346371e09709be8e46398bb097dc690a746f2 (patch) | |
| tree | aa68fa10037095d0ba23b0ca1465ed9296e6063b /hw/block | |
| parent | 248b23735645f7cbb503d9be6f5bf825f2a603ab (diff) | |
nvme: Fix get/set number of queues feature, again
The number of queues that should be return by the admin command should:
1) Only mention the number of non-admin queues.
2) It is zero-based, meaning that '0 == one non-admin queue',
'1 == two non-admin queues', and so forth.
Because our `num_queues` means the number of queues _plus_ the admin
queue, then the right calculation for the number returned from the admin
command is `num_queues - 2`, combining the two requirements mentioned.
The issue was discovered by reducing num_queues from 64 to 8 and running
a Linux VM with an SMP parameter larger than that (e.g. 22). It tries to
utilize all queues, and therefore fails with an invalid queue number
when trying to queue I/Os on the last queue.
Signed-off-by: Dan Aloni <dan@kernelim.com>
CC: Alex Friedman <alex@e8storage.com>
CC: Keith Busch <keith.busch@intel.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'hw/block')
| -rw-r--r-- | hw/block/nvme.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/hw/block/nvme.c b/hw/block/nvme.c index 6071dc12d8..9aa32692a3 100644 --- a/hw/block/nvme.c +++ b/hw/block/nvme.c @@ -615,7 +615,7 @@ static uint16_t nvme_get_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req) result = blk_enable_write_cache(n->conf.blk); break; case NVME_NUMBER_OF_QUEUES: - result = cpu_to_le32((n->num_queues - 1) | ((n->num_queues - 1) << 16)); + result = cpu_to_le32((n->num_queues - 2) | ((n->num_queues - 2) << 16)); break; default: return NVME_INVALID_FIELD | NVME_DNR; @@ -636,7 +636,7 @@ static uint16_t nvme_set_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req) break; case NVME_NUMBER_OF_QUEUES: req->cqe.result = - cpu_to_le32((n->num_queues - 1) | ((n->num_queues - 1) << 16)); + cpu_to_le32((n->num_queues - 2) | ((n->num_queues - 2) << 16)); break; default: return NVME_INVALID_FIELD | NVME_DNR; |