[PATCH v2 2/2] virtio_scsi: Implement fc_host

Fam Zheng
2017-01-26T03:41:41Z

This implements the VIRTIO_SCSI_F_FC_HOST feature by reading the config
fields and presenting them as sysfs fc_host attributes. The config
change handler is added here because primary_active will toggle during
migration.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
drivers/scsi/virtio_scsi.c | 60 +++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 59 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index ec91bd0..1bb330c 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -28,6 +28,7 @@
#include <scsi/scsi_device.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_tcq.h>
+#include <scsi/scsi_transport_fc.h>
#include <linux/seqlock.h>

#define VIRTIO_SCSI_MEMPOOL_SZ 64
@@ -795,6 +796,15 @@ static struct scsi_host_template virtscsi_host_template_multi = {
.track_queue_depth = 1,
};

+static struct fc_function_template virtscsi_fc_template = {
+ .show_host_node_name = 1,
+ .show_host_port_name = 1,
+ .show_host_port_type = 1,
+ .show_host_port_state = 1,
+};
+
+static struct scsi_transport_template *virtscsi_fc_transport_template;
+
#define virtscsi_config_get(vdev, fld) \
({ \
typeof(((struct virtio_scsi_config *)0)->fld) __val; \
@@ -956,15 +966,42 @@ static int virtscsi_init(struct virtio_device *vdev,
return err;
}

+static void virtscsi_update_fc_host_attrs(struct virtio_device *vdev)
+{
+ struct Scsi_Host *shost = vdev->priv;
+ u8 node_name[8], port_name[8];
+
+ if (virtscsi_config_get(vdev, primary_active)) {
+ virtio_cread_bytes(vdev,
+ offsetof(struct virtio_scsi_config, primary_wwnn),
+ &node_name, 8);
+ virtio_cread_bytes(vdev,
+ offsetof(struct virtio_scsi_config, primary_wwpn),
+ &port_name, 8);
+ } else {
+ virtio_cread_bytes(vdev,
+ offsetof(struct virtio_scsi_config, secondary_wwnn),
+ &node_name, 8);
+ virtio_cread_bytes(vdev,
+ offsetof(struct virtio_scsi_config, secondary_wwpn),
+ &port_name, 8);
+ }
+ fc_host_node_name(shost) = wwn_to_u64(node_name);
+ fc_host_port_name(shost) = wwn_to_u64(port_name);
+ fc_host_port_type(shost) = FC_PORTTYPE_NPORT;
+ fc_host_port_state(shost) = FC_PORTSTATE_ONLINE;
+}
+
static int virtscsi_probe(struct virtio_device *vdev)
{
- struct Scsi_Host *shost;
+ struct Scsi_Host *shost = NULL;
struct virtio_scsi *vscsi;
int err;
u32 sg_elems, num_targets;
u32 cmd_per_lun;
u32 num_queues;
struct scsi_host_template *hostt;
+ bool fc_host_enabled;

if (!vdev->config->get) {
dev_err(&vdev->dev, "%s failure: config access disabled\n",
@@ -987,6 +1024,9 @@ static int virtscsi_probe(struct virtio_device *vdev)
if (!shost)
return -ENOMEM;

+ fc_host_enabled = virtio_has_feature(vdev, VIRTIO_SCSI_F_FC_HOST);
+ if (fc_host_enabled)
+ shost->transportt = virtscsi_fc_transport_template;
sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
shost->sg_tablesize = sg_elems;
vscsi = shost_priv(shost);
@@ -1032,6 +1072,9 @@ static int virtscsi_probe(struct virtio_device *vdev)
if (err)
goto scsi_add_host_failed;

+ if (fc_host_enabled)
+ virtscsi_update_fc_host_attrs(vdev);
+
virtio_device_ready(vdev);

if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
@@ -1098,6 +1141,11 @@ static int virtscsi_restore(struct virtio_device *vdev)
}
#endif

+static void virtscsi_config_changed(struct virtio_device *vdev)
+{
+ virtscsi_update_fc_host_attrs(vdev);
+}
+
static struct virtio_device_id id_table[] = {
{ VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
{ 0 },
@@ -1109,6 +1157,7 @@ static unsigned int features[] = {
#ifdef CONFIG_BLK_DEV_INTEGRITY
VIRTIO_SCSI_F_T10_PI,
#endif
+ VIRTIO_SCSI_F_FC_HOST,
};

static struct virtio_driver virtio_scsi_driver = {
@@ -1123,12 +1172,20 @@ static struct virtio_driver virtio_scsi_driver = {
.restore = virtscsi_restore,
#endif
.remove = virtscsi_remove,
+ .config_changed = virtscsi_config_changed,
};

static int __init init(void)
{
int ret = -ENOMEM;

+ virtscsi_fc_transport_template =
+ fc_attach_transport(&virtscsi_fc_template);
+ if (!virtscsi_fc_transport_template) {
+ pr_err("fc_attach_transport() failed\n");
+ goto error;
+ }
+
virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
if (!virtscsi_cmd_cache) {
pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
@@ -1176,6 +1233,7 @@ static int __init init(void)

static void __exit fini(void)
{
+ fc_release_transport(virtscsi_fc_transport_template);
unregister_virtio_driver(&virtio_scsi_driver);
cpuhp_remove_multi_state(virtioscsi_online);
cpuhp_remove_multi_state(CPUHP_VIRT_SCSI_DEAD);
--
2.9.3