nvmet: add Command Set Identifier support

NVMe TP 4056 allows controllers to support different command sets.
NVMeoF target currently only supports namespaces that contain
traditional logical blocks that may be randomly read and written. In
some applications there is a value in exposing namespaces that contain
logical blocks that have special access rules (e.g. sequentially write
required namespace such as Zoned Namespace (ZNS)).

In order to support the Zoned Block Devices (ZBD) backend, controllers
need to have support for ZNS Command Set Identifier (CSI).

In this preparation patch, we adjust the code such that it can now
support the default command set identifier. We update the namespace data
structure to store the CSI value which defaults to NVME_CSI_NVM
that represents traditional logical blocks namespace type.

The CSI support is required to implement the ZBD backend for NVMeOF
with host side NVMe ZNS interface, since ZNS commands belong to
the different command set than the default one.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 62 insertions, 13 deletions

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 3de6a6c99b01..93aaa7479e71 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -162,15 +162,8 @@ out:
 	nvmet_req_complete(req, status);
 }
 
-static void nvmet_execute_get_log_cmd_effects_ns(struct nvmet_req *req)
+static void nvmet_get_cmd_effects_nvm(struct nvme_effects_log *log)
 {
-	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);
@@ -184,9 +177,30 @@ static void nvmet_execute_get_log_cmd_effects_ns(struct nvmet_req *req)
 	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));
+static void nvmet_execute_get_log_cmd_effects_ns(struct nvmet_req *req)
+{
+	struct nvme_effects_log *log;
+	u16 status = NVME_SC_SUCCESS;
+
+	log = kzalloc(sizeof(*log), GFP_KERNEL);
+	if (!log) {
+		status = NVME_SC_INTERNAL;
+		goto out;
+	}
+
+	switch (req->cmd->get_log_page.csi) {
+	case NVME_CSI_NVM:
+		nvmet_get_cmd_effects_nvm(log);
+		break;
+	default:
+		status = NVME_SC_INVALID_LOG_PAGE;
+		goto free;
+	}
 
+	status = nvmet_copy_to_sgl(req, 0, log, sizeof(*log));
+free:
 	kfree(log);
 out:
 	nvmet_req_complete(req, status);
@@ -613,6 +627,12 @@ static void nvmet_execute_identify_desclist(struct nvmet_req *req)
 			goto out;
 	}
 
+	status = nvmet_copy_ns_identifier(req, NVME_NIDT_CSI,
+					  NVME_NIDT_CSI_LEN,
+					  &req->ns->csi, &off);
+	if (status)
+		goto out;
+
 	if (sg_zero_buffer(req->sg, req->sg_cnt, NVME_IDENTIFY_DATA_SIZE - off,
 			off) != NVME_IDENTIFY_DATA_SIZE - off)
 		status = NVME_SC_INTERNAL | NVME_SC_DNR;
@@ -621,6 +641,17 @@ out:
 	nvmet_req_complete(req, status);
 }
 
+static bool nvmet_handle_identify_desclist(struct nvmet_req *req)
+{
+	switch (req->cmd->identify.csi) {
+	case NVME_CSI_NVM:
+		nvmet_execute_identify_desclist(req);
+		return true;
+	default:
+		return false;
+	}
+}
+
 static void nvmet_execute_identify(struct nvmet_req *req)
 {
 	if (!nvmet_check_transfer_len(req, NVME_IDENTIFY_DATA_SIZE))
@@ -628,13 +659,31 @@ static void nvmet_execute_identify(struct nvmet_req *req)
 
 	switch (req->cmd->identify.cns) {
 	case NVME_ID_CNS_NS:
-		return nvmet_execute_identify_ns(req);
+		switch (req->cmd->identify.csi) {
+		case NVME_CSI_NVM:
+			return nvmet_execute_identify_ns(req);
+		default:
+			break;
+		}
+		break;
 	case NVME_ID_CNS_CTRL:
-		return nvmet_execute_identify_ctrl(req);
+		switch (req->cmd->identify.csi) {
+		case NVME_CSI_NVM:
+			return nvmet_execute_identify_ctrl(req);
+		}
+		break;
 	case NVME_ID_CNS_NS_ACTIVE_LIST:
-		return nvmet_execute_identify_nslist(req);
+		switch (req->cmd->identify.csi) {
+		case NVME_CSI_NVM:
+			return nvmet_execute_identify_nslist(req);
+		default:
+			break;
+		}
+		break;
 	case NVME_ID_CNS_NS_DESC_LIST:
-		return nvmet_execute_identify_desclist(req);
+		if (nvmet_handle_identify_desclist(req) == true)
+			return;
+		break;
 	}
 
 	nvmet_req_cns_error_complete(req);