bdev_virtio: define virtio devs in separate config sections

This is required for adding
optional params for vdevs.

Since virtio-initiator README.md
had to be changed, some outdated
entries from TODO section has
been removed as a part of this
patch as well.

Change-Id: I472a966d8e4166305fb19ad3ab20e53289a1e071
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/382347
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>

lib/bdev/virtio/README.md

@@ -23,8 +23,8 @@ Use the following configuration file snippet to enumerate a virtio-scsi PCI
 device and present its LUNs as bdevs.
 
 ~~~{.sh}
-[Virtio]
+[VirtioPci]
-  Dev Pci
+  Enable Yes
 ~~~
 
 Use the following configuration file snippet to enumerate an SPDK vhost-scsi
@@ -33,14 +33,11 @@ target has created an SPDK vhost-scsi controller which is accessible through
 the /tmp/vhost.0 domain socket.
 
 ~~~{.sh}
-[Virtio]
+[VirtioUser0]
-  Dev User /tmp/vhost.0
+  Path /tmp/vhost.0
 ~~~
 
 ## Todo:
-* Support multiple PCI devices, including specifying the PCI device by PCI
-  bus/domain/function.
-* Add unmap support.
 * Add I/O channel support.  Includes requesting correct number of queues
   (based on core count).  Fail device initialization if not enough queues 
   can be allocated.
@@ -57,16 +54,7 @@ the /tmp/vhost.0 domain socket.
   scsi and blk.  If these should be separate, then this driver should be
   renamed to something scsi specific.
 * Add reset support.
-* Finish cleaning up "eth" references.  This includes filenames like
-  virtio_ethdev.c and "eth" in various API calls.
 * Understand and handle queue full conditions.
-* Clear interrupt flag for completions - since we are polling, we do not
-  need the virtio-scsi backend to signal completion.
-* Check interrupt flag for submission.  If the backend requires an interrupt,
-  we need to signal it.
-* Change read/write to use READ_16/WRITE_16 to handle LBA > 4G.  We can add
-  a basic check and bail during enumeration if INQUIRY indicates the LUN does
-  not support >= SBC-3.
 * Automated test scripts for both PCI and vhost-user scenarios.
 * Document Virtio config file section in examples.  Should wait on this until
   enough of the above items are implemented to consider this module as ready

lib/bdev/virtio/bdev_virtio.c

@@ -600,46 +600,75 @@ scan_target(struct virtio_scsi_scan_base *base)
 }
 
 static int
-bdev_virtio_initialize(void)
+bdev_virtio_process_config(void)
 {
-	struct spdk_conf_section *sp = spdk_conf_find_section(NULL, "Virtio");
+	struct spdk_conf_section *sp;
-	struct virtio_scsi_scan_base *base;
 	struct virtio_dev *vdev = NULL;
-	char *type, *path;
+	char *path;
-	uint32_t i;
+	unsigned vdev_num;
+	bool enable_pci;
 	int rc = 0;
-	bool scan_pci = false;
 
-	if (sp == NULL) {
+	for (sp = spdk_conf_first_section(NULL); sp != NULL; sp = spdk_conf_next_section(sp)) {
+		if (!spdk_conf_section_match_prefix(sp, "VirtioUser")) {
+			continue;
+		}
+
+		if (sscanf(spdk_conf_section_get_name(sp), "VirtioUser%u", &vdev_num) != 1) {
+			SPDK_ERRLOG("Section '%s' has non-numeric suffix.\n",
+				    spdk_conf_section_get_name(sp));
+			rc = -1;
 			goto out;
 		}
 
-	for (i = 0; spdk_conf_section_get_nval(sp, "Dev", i) != NULL; i++) {
+		path = spdk_conf_section_get_val(sp, "Path");
-		type = spdk_conf_section_get_nmval(sp, "Dev", i, 0);
-		if (type == NULL) {
-			SPDK_ERRLOG("No type specified for index %d\n", i);
-			continue;
-		}
-		if (!strcmp("User", type)) {
-			path = spdk_conf_section_get_nmval(sp, "Dev", i, 1);
 		if (path == NULL) {
-				SPDK_ERRLOG("No path specified for index %d\n", i);
+			SPDK_ERRLOG("VirtioUser%u: missing Path\n", vdev_num);
-				continue;
+			rc = -1;
+			goto out;
 		}
+
 		vdev = virtio_user_dev_init(path, 512);
 		if (vdev == NULL) {
+			rc = -1;
 			goto out;
 		}
-		} else if (!strcmp("Pci", type)) {
-			scan_pci = true;
-		} else {
-			SPDK_ERRLOG("Invalid type %s specified for index %d\n", type, i);
-			continue;
-		}
 	}
 
-	if (scan_pci) {
+	sp = spdk_conf_find_section(NULL, "VirtioPci");
-		vtpci_enumerate_pci();
+	if (sp == NULL) {
+		return 0;
+	}
+
+	enable_pci = spdk_conf_section_get_boolval(sp, "Enable", false);
+	if (enable_pci) {
+		rc = vtpci_enumerate_pci();
+	}
+
+	return rc;
+out:
+	if (vdev) {
+		virtio_dev_free(vdev);
+	}
+	return rc;
+}
+
+
+static int
+bdev_virtio_initialize(void)
+{
+	struct virtio_scsi_scan_base *base;
+	struct virtio_dev *vdev = NULL;
+	int rc = 0;
+
+	rc = bdev_virtio_process_config();
+	if (rc != 0) {
+		goto out;
+	}
+
+	if (TAILQ_EMPTY(&g_virtio_driver.init_ctrlrs)) {
+		spdk_bdev_module_init_done(SPDK_GET_BDEV_MODULE(virtio_scsi));
+		return 0;
 	}
 
 	TAILQ_FOREACH(vdev, &g_virtio_driver.init_ctrlrs, tailq) {
@@ -672,10 +701,6 @@ bdev_virtio_initialize(void)
 	return 0;
 
 out:
-	if (vdev) {
-		virtio_dev_free(vdev);
-	}
-
 	spdk_bdev_module_init_done(SPDK_GET_BDEV_MODULE(virtio_scsi));
 	return rc;
 }

test/vhost/initiator/bdev.conf.in

@@ -1,5 +1,5 @@
-[Virtio]
+[VirtioUser0]
-  Dev User /tmp/vhost.0
+  Path /tmp/vhost.0
 
 [Rpc]
   Enable Yes