[PATCH 3/3] hw/block/nvme: report non-mdts command size limit for dsm

[Klaus Jensen]

From: Gollu Appalanaidu <anaidu.gollu@samsung.com>

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>
---
 hw/block/nvme.h       |  1 +
 include/block/nvme.h  | 11 +++++++++++
 hw/block/nvme.c       | 30 ++++++++++++++++++++----------
 hw/block/trace-events |  1 +
 4 files changed, 33 insertions(+), 10 deletions(-)

diff --git a/hw/block/nvme.h b/hw/block/nvme.h
index cb2b5175f1a1..3046b82b3da1 100644
--- a/hw/block/nvme.h
+++ b/hw/block/nvme.h
@@ -172,6 +172,7 @@ typedef struct NvmeCtrl {
     int         aer_queued;
 
     uint8_t     zasl;
+    uint32_t    dmrsl;
 
     NvmeSubsystem   *subsys;
 
diff --git a/include/block/nvme.h b/include/block/nvme.h
index b23f3ae2279f..16d8c4c90f7e 100644
--- a/include/block/nvme.h
+++ b/include/block/nvme.h
@@ -1041,6 +1041,16 @@ typedef struct NvmeIdCtrlZoned {
     uint8_t     rsvd1[4095];
 } NvmeIdCtrlZoned;
 
+typedef struct NvmeIdCtrlNvm {
+    uint8_t     vsl;
+    uint8_t     wzsl;
+    uint8_t     wusl;
+    uint8_t     dmrl;
+    uint32_t    dmrsl;
+    uint64_t    dmsl;
+    uint8_t     rsvd16[4080];
+} NvmeIdCtrlNvm;
+
 enum NvmeIdCtrlOacs {
     NVME_OACS_SECURITY  = 1 << 0,
     NVME_OACS_FORMAT    = 1 << 1,
@@ -1396,6 +1406,7 @@ static inline void _nvme_check_size(void)
     QEMU_BUILD_BUG_ON(sizeof(NvmeEffectsLog) != 4096);
     QEMU_BUILD_BUG_ON(sizeof(NvmeIdCtrl) != 4096);
     QEMU_BUILD_BUG_ON(sizeof(NvmeIdCtrlZoned) != 4096);
+    QEMU_BUILD_BUG_ON(sizeof(NvmeIdCtrlNvm) != 4096);
     QEMU_BUILD_BUG_ON(sizeof(NvmeLBAF) != 4);
     QEMU_BUILD_BUG_ON(sizeof(NvmeLBAFE) != 16);
     QEMU_BUILD_BUG_ON(sizeof(NvmeIdNs) != 4096);
diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index 897b9ff0db91..5d6bba5fcb0d 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -1777,6 +1777,10 @@ 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);
 
@@ -3202,21 +3206,24 @@ 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) {
-        if (n->params.zasl_bs) {
-            id.zasl = n->zasl;
-        }
-        return nvme_dma(n, (uint8_t *)&id, sizeof(id),
-                        DMA_DIRECTION_FROM_DEVICE, req);
+    switch (c->csi) {
+    case NVME_CSI_NVM:
+        ((NvmeIdCtrlNvm *)&id)->dmrsl = cpu_to_le32(n->dmrsl);
+        break;
+
+    case NVME_CSI_ZONED:
+        ((NvmeIdCtrlZoned *)&id)->zasl = n->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)
@@ -4670,6 +4677,9 @@ 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/trace-events b/hw/block/trace-events
index 1f958d09d2a9..27940fe2e98a 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""
-- 
2.30.1