nvmet: add ZBD over ZNS backend support

NVMe TP 4053 – Zoned Namespaces (ZNS) allows host software to
communicate with a non-volatile memory subsystem using zones for NVMe
protocol-based controllers. NVMeOF already support the ZNS NVMe
Protocol compliant devices on the target in the passthru mode. There
are generic zoned block devices like  Shingled Magnetic Recording (SMR)
HDDs that are not based on the NVMe protocol.

This patch adds ZNS backend support for non-ZNS zoned block devices as
NVMeOF targets.

This support includes implementing the new command set NVME_CSI_ZNS,
adding different command handlers for ZNS command set such as NVMe
Identify Controller, NVMe Identify Namespace, NVMe Zone Append,
NVMe Zone Management Send and NVMe Zone Management Receive.

With the new command set identifier, we also update the target command
effects logs to reflect the ZNS compliant commands.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 41 insertions, 0 deletions

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 93aaa7479e71..363e357d2f20 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -179,6 +179,13 @@ static void nvmet_get_cmd_effects_nvm(struct nvme_effects_log *log)
 	log->iocs[nvme_cmd_write_zeroes]	= cpu_to_le32(1 << 0);
 }
 
+static void nvmet_get_cmd_effects_zns(struct nvme_effects_log *log)
+{
+	log->iocs[nvme_cmd_zone_append]		= cpu_to_le32(1 << 0);
+	log->iocs[nvme_cmd_zone_mgmt_send]	= cpu_to_le32(1 << 0);
+	log->iocs[nvme_cmd_zone_mgmt_recv]	= cpu_to_le32(1 << 0);
+}
+
 static void nvmet_execute_get_log_cmd_effects_ns(struct nvmet_req *req)
 {
 	struct nvme_effects_log *log;
@@ -194,6 +201,14 @@ static void nvmet_execute_get_log_cmd_effects_ns(struct nvmet_req *req)
 	case NVME_CSI_NVM:
 		nvmet_get_cmd_effects_nvm(log);
 		break;
+	case NVME_CSI_ZNS:
+		if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED)) {
+			status = NVME_SC_INVALID_IO_CMD_SET;
+			goto free;
+		}
+		nvmet_get_cmd_effects_nvm(log);
+		nvmet_get_cmd_effects_zns(log);
+		break;
 	default:
 		status = NVME_SC_INVALID_LOG_PAGE;
 		goto free;
@@ -647,6 +662,12 @@ static bool nvmet_handle_identify_desclist(struct nvmet_req *req)
 	case NVME_CSI_NVM:
 		nvmet_execute_identify_desclist(req);
 		return true;
+	case NVME_CSI_ZNS:
+		if (IS_ENABLED(CONFIG_BLK_DEV_ZONED)) {
+			nvmet_execute_identify_desclist(req);
+			return true;
+		}
+		return false;
 	default:
 		return false;
 	}
@@ -666,12 +687,32 @@ static void nvmet_execute_identify(struct nvmet_req *req)
 			break;
 		}
 		break;
+	case NVME_ID_CNS_CS_NS:
+		if (IS_ENABLED(CONFIG_BLK_DEV_ZONED)) {
+			switch (req->cmd->identify.csi) {
+			case NVME_CSI_ZNS:
+				return nvmet_execute_identify_cns_cs_ns(req);
+			default:
+				break;
+			}
+		}
+		break;
 	case NVME_ID_CNS_CTRL:
 		switch (req->cmd->identify.csi) {
 		case NVME_CSI_NVM:
 			return nvmet_execute_identify_ctrl(req);
 		}
 		break;
+	case NVME_ID_CNS_CS_CTRL:
+		if (IS_ENABLED(CONFIG_BLK_DEV_ZONED)) {
+			switch (req->cmd->identify.csi) {
+			case NVME_CSI_ZNS:
+				return nvmet_execute_identify_cns_cs_ctrl(req);
+			default:
+				break;
+			}
+		}
+		break;
 	case NVME_ID_CNS_NS_ACTIVE_LIST:
 		switch (req->cmd->identify.csi) {
 		case NVME_CSI_NVM: