From: Klaus Jensen <k.jensen@samsung.com>

Add a 'dbcs' knob to allow Doorbell Buffer Config command to be
disabled.

Reviewed-by: Jesper Wendel Devantier <foss@defmacro.it>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
---
 hw/nvme/ctrl.c       | 11 ++++++++---
 hw/nvme/nvme.h       |  1 +
 include/block/nvme.h |  2 +-
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
index 4ee8588ca9ae..1ad76da943a6 100644
--- a/hw/nvme/ctrl.c
+++ b/hw/nvme/ctrl.c
@@ -278,7 +278,6 @@ static const uint32_t nvme_cse_acs_default[256] = {
     [NVME_ADM_CMD_GET_FEATURES]     = NVME_CMD_EFF_CSUPP,
     [NVME_ADM_CMD_ASYNC_EV_REQ]     = NVME_CMD_EFF_CSUPP,
     [NVME_ADM_CMD_NS_ATTACHMENT]    = NVME_CMD_EFF_CSUPP | NVME_CMD_EFF_NIC,
-    [NVME_ADM_CMD_DBBUF_CONFIG]     = NVME_CMD_EFF_CSUPP,
     [NVME_ADM_CMD_FORMAT_NVM]       = NVME_CMD_EFF_CSUPP | NVME_CMD_EFF_LBCC,
     [NVME_ADM_CMD_DIRECTIVE_RECV]   = NVME_CMD_EFF_CSUPP,
     [NVME_ADM_CMD_DIRECTIVE_SEND]   = NVME_CMD_EFF_CSUPP,
@@ -8773,8 +8772,13 @@ static void nvme_init_ctrl(NvmeCtrl *n, PCIDevice *pci_dev)
     id->mdts = n->params.mdts;
     id->ver = cpu_to_le32(NVME_SPEC_VER);
 
-    oacs = NVME_OACS_NMS | NVME_OACS_FORMAT | NVME_OACS_DBBUF |
-        NVME_OACS_DIRECTIVES;
+    oacs = NVME_OACS_NMS | NVME_OACS_FORMAT | NVME_OACS_DIRECTIVES;
+
+    if (n->params.dbcs) {
+        oacs |= NVME_OACS_DBCS;
+
+        n->cse.acs[NVME_ADM_CMD_DBBUF_CONFIG] = NVME_CMD_EFF_CSUPP;
+    }
 
     if (n->params.sriov_max_vfs) {
         oacs |= NVME_OACS_VMS;
@@ -9024,6 +9028,7 @@ static const Property nvme_props[] = {
     DEFINE_PROP_BOOL("use-intel-id", NvmeCtrl, params.use_intel_id, false),
     DEFINE_PROP_BOOL("legacy-cmb", NvmeCtrl, params.legacy_cmb, false),
     DEFINE_PROP_BOOL("ioeventfd", NvmeCtrl, params.ioeventfd, false),
+    DEFINE_PROP_BOOL("dbcs", NvmeCtrl, params.dbcs, true),
     DEFINE_PROP_UINT8("zoned.zasl", NvmeCtrl, params.zasl, 0),
     DEFINE_PROP_BOOL("zoned.auto_transition", NvmeCtrl,
                      params.auto_transition_zones, true),
diff --git a/hw/nvme/nvme.h b/hw/nvme/nvme.h
index b86cad388f5a..b8d063a027a9 100644
--- a/hw/nvme/nvme.h
+++ b/hw/nvme/nvme.h
@@ -539,6 +539,7 @@ typedef struct NvmeParams {
     bool     auto_transition_zones;
     bool     legacy_cmb;
     bool     ioeventfd;
+    bool     dbcs;
     uint16_t  sriov_max_vfs;
     uint16_t sriov_vq_flexible;
     uint16_t sriov_vi_flexible;
diff --git a/include/block/nvme.h b/include/block/nvme.h
index 80fbcb420d48..63eb74460eac 100644
--- a/include/block/nvme.h
+++ b/include/block/nvme.h
@@ -1235,7 +1235,7 @@ enum NvmeIdCtrlOacs {
     NVME_OACS_NMS           = 1 << 3,
     NVME_OACS_DIRECTIVES    = 1 << 5,
     NVME_OACS_VMS           = 1 << 7,
-    NVME_OACS_DBBUF         = 1 << 8,
+    NVME_OACS_DBCS          = 1 << 8,
 };
 
 enum NvmeIdCtrlOncs {
-- 
2.47.2