hw/block/nvme: report non-mdts command size limit for dsm

Dataset Management is not subject to MDTS, but exceeded a certain size
per range causes internal looping. Report this limit (DMRSL) in the NVM
command set specific identify controller data structure.

Signed-off-by: Gollu Appalanaidu <anaidu.gollu@samsung.com>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>

3 files changed, 22 insertions, 8 deletions

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index b81c4c3705..30aef5b09e 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -1789,6 +1789,10 @@ static uint16_t nvme_dsm(NvmeCtrl *n, NvmeRequest *req)
             trace_pci_nvme_dsm_deallocate(nvme_cid(req), nvme_nsid(ns), slba,
                                           nlb);
 
+            if (nlb > n->dmrsl) {
+                trace_pci_nvme_dsm_single_range_limit_exceeded(nlb, n->dmrsl);
+            }
+
             offset = nvme_l2b(ns, slba);
             len = nvme_l2b(ns, nlb);
 
@@ -3208,20 +3212,24 @@ static uint16_t nvme_identify_ctrl(NvmeCtrl *n, NvmeRequest *req)
 static uint16_t nvme_identify_ctrl_csi(NvmeCtrl *n, NvmeRequest *req)
 {
     NvmeIdentify *c = (NvmeIdentify *)&req->cmd;
-    NvmeIdCtrlZoned id = {};
+    uint8_t id[NVME_IDENTIFY_DATA_SIZE] = {};
 
     trace_pci_nvme_identify_ctrl_csi(c->csi);
 
-    if (c->csi == NVME_CSI_NVM) {
-        return nvme_rpt_empty_id_struct(n, req);
-    } else if (c->csi == NVME_CSI_ZONED) {
-        id.zasl = n->params.zasl;
+    switch (c->csi) {
+    case NVME_CSI_NVM:
+        ((NvmeIdCtrlNvm *)&id)->dmrsl = cpu_to_le32(n->dmrsl);
+        break;
 
-        return nvme_dma(n, (uint8_t *)&id, sizeof(id),
-                        DMA_DIRECTION_FROM_DEVICE, req);
+    case NVME_CSI_ZONED:
+        ((NvmeIdCtrlZoned *)&id)->zasl = n->params.zasl;
+        break;
+
+    default:
+        return NVME_INVALID_FIELD | NVME_DNR;
     }
 
-    return NVME_INVALID_FIELD | NVME_DNR;
+    return nvme_dma(n, id, sizeof(id), DMA_DIRECTION_FROM_DEVICE, req);
 }
 
 static uint16_t nvme_identify_ns(NvmeCtrl *n, NvmeRequest *req)
@@ -4655,6 +4663,9 @@ int nvme_register_namespace(NvmeCtrl *n, NvmeNamespace *ns, Error **errp)
 
     n->namespaces[nsid - 1] = ns;
 
+    n->dmrsl = MIN_NON_ZERO(n->dmrsl,
+                            BDRV_REQUEST_MAX_BYTES / nvme_l2b(ns, 1));
+
     return 0;
 }
 
diff --git a/hw/block/nvme.h b/hw/block/nvme.h
index f45ace0cff..294fac1def 100644
--- a/hw/block/nvme.h
+++ b/hw/block/nvme.h
@@ -171,6 +171,8 @@ typedef struct NvmeCtrl {
     QTAILQ_HEAD(, NvmeAsyncEvent) aer_queue;
     int         aer_queued;
 
+    uint32_t    dmrsl;
+
     NvmeSubsystem   *subsys;
 
     NvmeNamespace   namespace;
diff --git a/hw/block/trace-events b/hw/block/trace-events
index c165ee2a97..8deeacc8c3 100644
--- a/hw/block/trace-events
+++ b/hw/block/trace-events
@@ -51,6 +51,7 @@ pci_nvme_copy_cb(uint16_t cid) "cid %"PRIu16""
 pci_nvme_block_status(int64_t offset, int64_t bytes, int64_t pnum, int ret, bool zeroed) "offset %"PRId64" bytes %"PRId64" pnum %"PRId64" ret 0x%x zeroed %d"
 pci_nvme_dsm(uint16_t cid, uint32_t nsid, uint32_t nr, uint32_t attr) "cid %"PRIu16" nsid %"PRIu32" nr %"PRIu32" attr 0x%"PRIx32""
 pci_nvme_dsm_deallocate(uint16_t cid, uint32_t nsid, uint64_t slba, uint32_t nlb) "cid %"PRIu16" nsid %"PRIu32" slba %"PRIu64" nlb %"PRIu32""
+pci_nvme_dsm_single_range_limit_exceeded(uint32_t nlb, uint32_t dmrsl) "nlb %"PRIu32" dmrsl %"PRIu32""
 pci_nvme_compare(uint16_t cid, uint32_t nsid, uint64_t slba, uint32_t nlb) "cid %"PRIu16" nsid %"PRIu32" slba 0x%"PRIx64" nlb %"PRIu32""
 pci_nvme_compare_cb(uint16_t cid) "cid %"PRIu16""
 pci_nvme_aio_discard_cb(uint16_t cid) "cid %"PRIu16""