mi_xfer: Added nvme_mi_mi_xfer API

This is added to be analogous to nvme_mi_admin_xfer, providing a way for
the application to implement vendor specific mi commands.

Signed-off-by: Chuck Horkin <chorkin@microsoft.com>

Author: chorkin

src/libnvme-mi.map

@@ -1,3 +1,8 @@
+LIBNVME_MI_1_12 {
+	global:
+		nvme_mi_mi_xfer;
+};
+
 LIBNVME_MI_1_11 {
 	global:
 		nvme_mi_control;

src/nvme/mi.c

@@ -1599,6 +1599,72 @@ static int nvme_mi_read_data(nvme_mi_ep_t ep, __u32 cdw0,
 	return 0;
 }
 
+int nvme_mi_mi_xfer(nvme_mi_ep_t ep,
+		       struct nvme_mi_mi_req_hdr *mi_req,
+		       size_t req_data_size,
+		       struct nvme_mi_mi_resp_hdr *mi_resp,
+		       size_t *resp_data_size)
+{
+	int rc;
+	struct nvme_mi_req req;
+	struct nvme_mi_resp resp;
+
+	/* There is nothing in the spec to define this limit but going with the limits
+	 * from the admin message types for DLEN seems like a reasonable starting point
+	 * to check for coding errors
+	 */
+	const size_t mi_data_xfer_size_limit = 4096;
+
+	/* length/offset checks. The common _submit() API will do further
+	 * checking on the message lengths too, so these are kept specific
+	 * to the requirements of the particular command set
+	 */
+
+	if (*resp_data_size > mi_data_xfer_size_limit) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	/* request and response lengths & offset must be aligned */
+	if ((req_data_size & 0x3) ||
+	    (*resp_data_size & 0x3)) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	/* bidirectional not permitted */
+	if (req_data_size && *resp_data_size) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	mi_req->hdr.type = NVME_MI_MSGTYPE_NVME;
+	mi_req->hdr.nmp = (NVME_MI_ROR_REQ << 7) |
+				(NVME_MI_MT_MI << 3);
+
+	memset(&req, 0, sizeof(req));
+	req.hdr = &mi_req->hdr;
+	req.hdr_len = sizeof(*mi_req);
+	req.data = mi_req + 1;
+	req.data_len = req_data_size;
+
+	nvme_mi_calc_req_mic(&req);
+
+	memset(&resp, 0, sizeof(resp));
+	resp.hdr = &mi_resp->hdr;
+	resp.hdr_len = sizeof(*mi_resp);
+	resp.data = mi_resp + 1;
+	resp.data_len = *resp_data_size;
+
+	rc = nvme_mi_submit(ep, &req, &resp);
+	if (rc)
+		return rc;
+
+	*resp_data_size = resp.data_len;
+
+	return 0;
+}
+
 int nvme_mi_mi_read_mi_data_subsys(nvme_mi_ep_t ep,
 				   struct nvme_mi_read_nvm_ss_info *s)
 {

src/nvme/mi.h

@@ -729,6 +729,36 @@ char *nvme_mi_endpoint_desc(nvme_mi_ep_t ep);
 
 /* MI Command API: nvme_mi_mi_ prefix */
 
+/**
+ * nvme_mi_mi_xfer() -  Raw mi transfer interface.
+ * @ep: endpoint to send the MI command to
+ * @mi_req: request data
+ * @req_data_size: size of request data payload
+ * @mi_resp: buffer for response data
+ * @resp_data_size: size of response data buffer, updated to received size
+ *
+ * Performs an arbitrary NVMe MI command, using the provided request data,
+ * in @mi_req. The size of the request data *payload* is specified in
+ * @req_data_size - this does not include the standard header length (so a
+ * header-only request would have a size of 0). Note that the Management
+ * Request Doublewords are considered part of the header data.
+ *
+ * On success, response data is stored in @mi_resp, which has an optional
+ * appended payload buffer of @resp_data_size bytes. The actual payload
+ * size transferred will be stored in @resp_data_size. This size does not
+ * include the MI response header, so 0 represents no payload.
+ *
+ * See: &struct nvme_mi_mi_req_hdr and &struct nvme_mi_mi_resp_hdr.
+ *
+ * Return: The nvme command status if a response was received (see
+ * &enum nvme_status_field) or -1 with errno set otherwise..
+ */
+int nvme_mi_mi_xfer(nvme_mi_ep_t ep,
+		       struct nvme_mi_mi_req_hdr *mi_req,
+		       size_t req_data_size,
+		       struct nvme_mi_mi_resp_hdr *mi_resp,
+		       size_t *resp_data_size);
+
 /**
  * nvme_mi_mi_read_mi_data_subsys() - Perform a Read MI Data Structure command,
  * retrieving subsystem data.

test/mi.c

@@ -566,8 +566,8 @@ static void test_admin_err_nvme_resp(nvme_mi_ep_t ep)
 		| NVME_SC_DNR));
 }
 
-/* invalid Admin command transfers */
-static int test_admin_invalid_formats_cb(struct nvme_mi_ep *ep,
+/* invalid command transfers */
+static int test_rejected_command_cb(struct nvme_mi_ep *ep,
 					 struct nvme_mi_req *req,
 					 struct nvme_mi_resp *resp,
 					 void *data)
@@ -588,7 +588,7 @@ static void test_admin_invalid_formats(nvme_mi_ep_t ep)
 	size_t len;
 	int rc;
 
-	test_set_transport_callback(ep, test_admin_invalid_formats_cb, NULL);
+	test_set_transport_callback(ep, test_rejected_command_cb, NULL);
 
 	ctrl = nvme_mi_init_ctrl(ep, 1);
 	assert(ctrl);
@@ -629,6 +629,44 @@ static void test_admin_invalid_formats(nvme_mi_ep_t ep)
 	assert(rc != 0);
 }
 
+static void test_mi_invalid_formats(nvme_mi_ep_t ep)
+{
+	struct {
+		struct nvme_mi_mi_req_hdr hdr;
+		uint8_t data[4];
+	} req = { 0 };
+	struct nvme_mi_mi_resp_hdr resp = { 0 };
+	nvme_mi_ctrl_t ctrl;
+	size_t len;
+	int rc;
+
+	test_set_transport_callback(ep, test_rejected_command_cb, NULL);
+
+	ctrl = nvme_mi_init_ctrl(ep, 1);
+	assert(ctrl);
+
+	/* unaligned req size */
+	len = 0;
+
+	rc = nvme_mi_mi_xfer(ep, &req.hdr, 1, &resp, &len);
+	assert(rc != 0);
+
+	/* unaligned resp size */
+	len = 1;
+	rc = nvme_mi_mi_xfer(ep, &req.hdr, 0, &resp, &len);
+	assert(rc != 0);
+
+	/* resp too large */
+	len = 4096 + 4;
+	rc = nvme_mi_mi_xfer(ep, &req.hdr, 0, &resp, &len);
+	assert(rc != 0);
+
+	/* req and resp payloads */
+	len = 4;
+	rc = nvme_mi_mi_xfer(ep, &req.hdr, 4, &resp, &len);
+	assert(rc != 0);
+}
+
 /* test: header length too small */
 static int test_resp_hdr_small_cb(struct nvme_mi_ep *ep,
 				  struct nvme_mi_req *req,
@@ -2049,6 +2087,7 @@ struct test {
 	DEFINE_TEST(endpoint_quirk_probe),
 	DEFINE_TEST(admin_dlen_doff_req),
 	DEFINE_TEST(admin_dlen_doff_resp),
+	DEFINE_TEST(mi_invalid_formats),
 };
 
 static void run_test(struct test *test, FILE *logfd, nvme_mi_ep_t ep)