nvmet: add commands supported and effects log page

This patch adds support for Commands Supported and Effects log page
(Log Identifier 05h) for NVMeOF. This also makes it easier to find
which commands are supported, e.g. :-

subnqn    : testnqn1
Admin Command Set
ACS2     [Get Log Page                    ] 00000001
ACS6     [Identify                        ] 00000001
ACS8     [Abort                           ] 00000001
ACS9     [Set Features                    ] 00000001
ACS10    [Get Features                    ] 00000001
ACS12    [Asynchronous Event Request      ] 00000001
ACS24    [Keep Alive                      ] 00000001

NVM Command Set
IOCS0    [Flush                           ] 00000001
IOCS1    [Write                           ] 00000001
IOCS2    [Read                            ] 00000001
IOCS8    [Write Zeroes                    ] 00000001
IOCS9    [Dataset Management              ] 00000001

This partticular functionality can be used from the host side to examine
the NVMeOF ctrl commands supported.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/target/admin-cmd.c

@@ -128,6 +128,36 @@ static void nvmet_execute_get_log_page_smart(struct nvmet_req *req)
 	nvmet_req_complete(req, status);
 }
 
+static void nvmet_execute_get_log_cmd_effects_ns(struct nvmet_req *req)
+{
+	u16 status = NVME_SC_INTERNAL;
+	struct nvme_effects_log *log;
+
+	log = kzalloc(sizeof(*log), GFP_KERNEL);
+	if (!log)
+		goto out;
+
+	log->acs[nvme_admin_get_log_page]	= cpu_to_le32(1 << 0);
+	log->acs[nvme_admin_identify]		= cpu_to_le32(1 << 0);
+	log->acs[nvme_admin_abort_cmd]		= cpu_to_le32(1 << 0);
+	log->acs[nvme_admin_set_features]	= cpu_to_le32(1 << 0);
+	log->acs[nvme_admin_get_features]	= cpu_to_le32(1 << 0);
+	log->acs[nvme_admin_async_event]	= cpu_to_le32(1 << 0);
+	log->acs[nvme_admin_keep_alive]		= cpu_to_le32(1 << 0);
+
+	log->iocs[nvme_cmd_read]		= cpu_to_le32(1 << 0);
+	log->iocs[nvme_cmd_write]		= cpu_to_le32(1 << 0);
+	log->iocs[nvme_cmd_flush]		= cpu_to_le32(1 << 0);
+	log->iocs[nvme_cmd_dsm]			= cpu_to_le32(1 << 0);
+	log->iocs[nvme_cmd_write_zeroes]	= cpu_to_le32(1 << 0);
+
+	status = nvmet_copy_to_sgl(req, 0, log, sizeof(*log));
+
+	kfree(log);
+out:
+	nvmet_req_complete(req, status);
+}
+
 static void nvmet_execute_get_log_changed_ns(struct nvmet_req *req)
 {
 	struct nvmet_ctrl *ctrl = req->sq->ctrl;
@@ -208,7 +238,7 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
 
 	/* first slot is read-only, only one slot supported */
 	id->frmw = (1 << 0) | (1 << 1);
-	id->lpa = (1 << 0) | (1 << 2);
+	id->lpa = (1 << 0) | (1 << 1) | (1 << 2);
 	id->elpe = NVMET_ERROR_LOG_SLOTS - 1;
 	id->npss = 0;
 
@@ -586,6 +616,9 @@ u16 nvmet_parse_admin_cmd(struct nvmet_req *req)
 		case NVME_LOG_CHANGED_NS:
 			req->execute = nvmet_execute_get_log_changed_ns;
 			return 0;
+		case NVME_LOG_CMD_EFFECTS:
+			req->execute = nvmet_execute_get_log_cmd_effects_ns;
+			return 0;
 		}
 		break;
 	case nvme_admin_identify: