scsi: target: core: Add emulate_rsoc attribute

Allow support for RSOC to be turned off via the emulate_rsoc attibute.
This is just for testing purposes.

Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Link: https://lore.kernel.org/r/20220906103421.22348-5-d.bogdanov@yadro.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/target/target_core_configfs.c

@@ -547,6 +547,7 @@ DEF_CONFIGFS_ATTRIB_SHOW(unmap_granularity);
 DEF_CONFIGFS_ATTRIB_SHOW(unmap_granularity_alignment);
 DEF_CONFIGFS_ATTRIB_SHOW(unmap_zeroes_data);
 DEF_CONFIGFS_ATTRIB_SHOW(max_write_same_len);
+DEF_CONFIGFS_ATTRIB_SHOW(emulate_rsoc);
 
 #define DEF_CONFIGFS_ATTRIB_STORE_U32(_name)				\
 static ssize_t _name##_store(struct config_item *item, const char *page,\
@@ -1186,6 +1187,23 @@ static ssize_t pgr_support_store(struct config_item *item,
 	return count;
 }
 
+static ssize_t emulate_rsoc_store(struct config_item *item,
+		const char *page, size_t count)
+{
+	struct se_dev_attrib *da = to_attrib(item);
+	bool flag;
+	int ret;
+
+	ret = strtobool(page, &flag);
+	if (ret < 0)
+		return ret;
+
+	da->emulate_rsoc = flag;
+	pr_debug("dev[%p]: SE Device REPORT_SUPPORTED_OPERATION_CODES_EMULATION flag: %d\n",
+			da->da_dev, flag);
+	return count;
+}
+
 CONFIGFS_ATTR(, emulate_model_alias);
 CONFIGFS_ATTR(, emulate_dpo);
 CONFIGFS_ATTR(, emulate_fua_write);
@@ -1198,6 +1216,7 @@ CONFIGFS_ATTR(, emulate_tpws);
 CONFIGFS_ATTR(, emulate_caw);
 CONFIGFS_ATTR(, emulate_3pc);
 CONFIGFS_ATTR(, emulate_pr);
+CONFIGFS_ATTR(, emulate_rsoc);
 CONFIGFS_ATTR(, pi_prot_type);
 CONFIGFS_ATTR_RO(, hw_pi_prot_type);
 CONFIGFS_ATTR(, pi_prot_format);
@@ -1261,6 +1280,7 @@ struct configfs_attribute *sbc_attrib_attrs[] = {
 	&attr_max_write_same_len,
 	&attr_alua_support,
 	&attr_pgr_support,
+	&attr_emulate_rsoc,
 	NULL,
 };
 EXPORT_SYMBOL(sbc_attrib_attrs);

drivers/target/target_core_device.c

@@ -785,6 +785,7 @@ struct se_device *target_alloc_device(struct se_hba *hba, const char *name)
 	dev->dev_attrib.emulate_caw = DA_EMULATE_CAW;
 	dev->dev_attrib.emulate_3pc = DA_EMULATE_3PC;
 	dev->dev_attrib.emulate_pr = DA_EMULATE_PR;
+	dev->dev_attrib.emulate_rsoc = DA_EMULATE_RSOC;
 	dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE0_PROT;
 	dev->dev_attrib.enforce_pr_isids = DA_ENFORCE_PR_ISIDS;
 	dev->dev_attrib.force_pr_aptpl = DA_FORCE_PR_APTPL;

drivers/target/target_core_spc.c

@@ -1889,6 +1889,14 @@ static struct target_opcode_descriptor tcm_opcode_report_target_pgs = {
 		       0xff, 0xff, 0x00, SCSI_CONTROL_MASK},
 };
 
+
+static bool spc_rsoc_enabled(struct se_cmd *cmd)
+{
+	struct se_device *dev = cmd->se_dev;
+
+	return dev->dev_attrib.emulate_rsoc;
+}
+
 static struct target_opcode_descriptor tcm_opcode_report_supp_opcodes = {
 	.support = SCSI_SUPPORT_FULL,
 	.serv_action_valid = 1,
@@ -1899,6 +1907,7 @@ static struct target_opcode_descriptor tcm_opcode_report_supp_opcodes = {
 		       0x87, 0xff,
 		       0xff, 0xff, 0xff, 0xff,
 		       0xff, 0xff, 0x00, SCSI_CONTROL_MASK},
+	.enabled = spc_rsoc_enabled,
 };
 
 static bool tcm_is_set_tpg_enabled(struct se_cmd *cmd)
@@ -2135,6 +2144,9 @@ spc_emulate_report_supp_op_codes(struct se_cmd *cmd)
 	sense_reason_t ret = 0;
 	int i;
 
+	if (!cmd->se_dev->dev_attrib.emulate_rsoc)
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+
 	rbuf = transport_kmap_data_sg(cmd);
 	if (cmd->data_length && !rbuf) {
 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

include/target/target_core_base.h

@@ -91,6 +91,8 @@
 #define DA_EMULATE_ALUA				0
 /* Emulate SCSI2 RESERVE/RELEASE and Persistent Reservations by default */
 #define DA_EMULATE_PR				1
+/* Emulation for REPORT SUPPORTED OPERATION CODES */
+#define DA_EMULATE_RSOC				1
 /* Enforce SCSI Initiator Port TransportID with 'ISID' for PR */
 #define DA_ENFORCE_PR_ISIDS			1
 /* Force SPC-3 PR Activate Persistence across Target Power Loss */
@@ -690,6 +692,7 @@ struct se_dev_attrib {
 	bool		emulate_caw;
 	bool		emulate_3pc;
 	bool		emulate_pr;
+	bool		emulate_rsoc;
 	enum target_prot_type pi_prot_type;
 	enum target_prot_type hw_pi_prot_type;
 	bool		pi_prot_verify;