NVMe: Configure support for block flush

This configures an nvme request_queue as flush capable if the device
has a volatile write cache present.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/uapi/linux/nvme.h b/include/uapi/linux/nvme.h
index ad9014e49693..f090336d5bad 100644
--- a/include/uapi/linux/nvme.h
+++ b/include/uapi/linux/nvme.h
@@ -73,6 +73,7 @@ enum {
         NVME_CTRL_ONCS_COMPARE                  = 1 << 0,
         NVME_CTRL_ONCS_WRITE_UNCORRECTABLE      = 1 << 1,
         NVME_CTRL_ONCS_DSM                      = 1 << 2,
+        NVME_CTRL_VWC_PRESENT                   = 1 << 0,
 };
 
 struct nvme_lbaf {