[Qemu-devel] [PATCH 5/8] nvme: add support for metadata

[Klaus Birkelund Jensen <klaus@birkelund.eu>]

The new `ms` parameter may be used to indicate the number of metadata
bytes provided per LBA.

Signed-off-by: Klaus Birkelund Jensen <klaus.jensen@cnexlabs.com>
---
 hw/block/nvme.c | 31 +++++++++++++++++++++++++++++--
 hw/block/nvme.h | 11 ++++++++++-
 2 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index c514f93f3867..675967a596d1 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -33,6 +33,8 @@
  *   num_ns=<int>          : Namespaces to make out of the backing storage,
  *                           Default:1
  *   num_queues=<int>      : Number of possible IO Queues, Default:64
+ *   ms=<int>              : Number of metadata bytes provided per LBA,
+ *                           Default:0
  *   cmb_size_mb=<int>     : Size of CMB in MBs, Default:0
  *
  * Parameters will be verified against conflicting capabilities and attributes
@@ -386,6 +388,8 @@ static uint16_t nvme_blk_map(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
 
     uint32_t unit_len = nvme_ns_lbads_bytes(ns);
     uint32_t len = req->nlb * unit_len;
+    uint32_t meta_unit_len = nvme_ns_ms(ns);
+    uint32_t meta_len = req->nlb * meta_unit_len;
     uint64_t prp1 = le64_to_cpu(cmd->prp1);
     uint64_t prp2 = le64_to_cpu(cmd->prp2);
 
@@ -399,6 +403,19 @@ static uint16_t nvme_blk_map(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
         return err;
     }
 
+    qsg.nsg = 0;
+    qsg.size = 0;
+
+    if (cmd->mptr && n->params.ms) {
+        qemu_sglist_add(&qsg, le64_to_cpu(cmd->mptr), meta_len);
+
+        err = nvme_blk_setup(n, ns, &qsg, ns->blk_offset_md, meta_unit_len,
+            req);
+        if (err) {
+            return err;
+        }
+    }
+
     qemu_sglist_destroy(&qsg);
 
     return NVME_SUCCESS;
@@ -1902,6 +1919,11 @@ static int nvme_check_constraints(NvmeCtrl *n, Error **errp)
         return 1;
     }
 
+    if (params->ms && !is_power_of_2(params->ms)) {
+        error_setg(errp, "nvme: invalid metadata configuration");
+        return 1;
+    }
+
     return 0;
 }
 
@@ -2066,17 +2088,20 @@ static void nvme_init_ctrl(NvmeCtrl *n)
 
 static uint64_t nvme_ns_calc_blks(NvmeCtrl *n, NvmeNamespace *ns)
 {
-    return n->ns_size / nvme_ns_lbads_bytes(ns);
+    return n->ns_size / (nvme_ns_lbads_bytes(ns) + nvme_ns_ms(ns));
 }
 
 static void nvme_ns_init_identify(NvmeCtrl *n, NvmeIdNs *id_ns)
 {
+    NvmeParams *params = &n->params;
+
     id_ns->nlbaf = 0;
     id_ns->flbas = 0;
-    id_ns->mc = 0;
+    id_ns->mc = params->ms ? 0x2 : 0;
     id_ns->dpc = 0;
     id_ns->dps = 0;
     id_ns->lbaf[0].lbads = BDRV_SECTOR_BITS;
+    id_ns->lbaf[0].ms = params->ms;
 }
 
 static int nvme_init_namespace(NvmeCtrl *n, NvmeNamespace *ns, Error **errp)
@@ -2086,6 +2111,8 @@ static int nvme_init_namespace(NvmeCtrl *n, NvmeNamespace *ns, Error **errp)
     nvme_ns_init_identify(n, id_ns);
 
     ns->ns_blks = nvme_ns_calc_blks(n, ns);
+    ns->blk_offset_md = ns->blk_offset + nvme_ns_lbads_bytes(ns) * ns->ns_blks;
+
     id_ns->nuse = id_ns->ncap = id_ns->nsze = cpu_to_le64(ns->ns_blks);
 
     return 0;
diff --git a/hw/block/nvme.h b/hw/block/nvme.h
index 711ca249eac5..81ee0c5173d5 100644
--- a/hw/block/nvme.h
+++ b/hw/block/nvme.h
@@ -8,13 +8,15 @@
     DEFINE_PROP_UINT32("cmb_size_mb", _state, _props.cmb_size_mb, 0), \
     DEFINE_PROP_UINT32("num_queues", _state, _props.num_queues, 64), \
     DEFINE_PROP_UINT32("num_ns", _state, _props.num_ns, 1), \
-    DEFINE_PROP_UINT8("mdts", _state, _props.mdts, 7)
+    DEFINE_PROP_UINT8("mdts", _state, _props.mdts, 7), \
+    DEFINE_PROP_UINT8("ms", _state, _props.ms, 0)
 
 typedef struct NvmeParams {
     char     *serial;
     uint32_t num_queues;
     uint32_t num_ns;
     uint8_t  mdts;
+    uint8_t  ms;
     uint32_t cmb_size_mb;
 } NvmeParams;
 
@@ -91,6 +93,7 @@ typedef struct NvmeNamespace {
     uint32_t        id;
     uint64_t        ns_blks;
     uint64_t        blk_offset;
+    uint64_t        blk_offset_md;
 } NvmeNamespace;
 
 #define TYPE_NVME "nvme"
@@ -154,4 +157,10 @@ static inline size_t nvme_ns_lbads_bytes(NvmeNamespace *ns)
     return 1 << nvme_ns_lbads(ns);
 }
 
+static inline uint16_t nvme_ns_ms(NvmeNamespace *ns)
+{
+    NvmeIdNs *id = &ns->id_ns;
+    return le16_to_cpu(id->lbaf[NVME_ID_NS_FLBAS_INDEX(id->flbas)].ms);
+}
+
 #endif /* HW_NVME_H */
-- 
2.21.0