From d21d37f5ab8c439ea183d8b04c469823d3b0b5ef Mon Sep 17 00:00:00 2001
From: Klaus Jensen <k.jensen@samsung.com>
Date: Mon, 6 Jul 2020 08:12:55 +0200
Subject: [PATCH] hw/block/nvme: flush write cache when disabled

If the write cache is disabled with a Set Features command, flush it if
currently enabled.

Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200706061303.246057-11-its@irrelevant.dk>
---
 hw/block/nvme.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index 41a15da3f6..298b250199 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -1181,6 +1181,10 @@ static uint16_t nvme_set_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
 
         break;
     case NVME_VOLATILE_WRITE_CACHE:
+        if (!(dw11 & 0x1) && blk_enable_write_cache(n->conf.blk)) {
+            blk_flush(n->conf.blk);
+        }
+
         blk_set_enable_write_cache(n->conf.blk, dw11 & 1);
         break;
     case NVME_NUMBER_OF_QUEUES: