tcm_vhost: Initial merge for vhost level target fabric driver
This patch adds the initial code for tcm_vhost, a Vhost level TCM
fabric driver for virtio SCSI initiators into KVM guest.
This code is currently up and running on v3.5-rc2 host+guest
from target-pending/for-next-merge.
Using tcm_vhost requires Zhi's -> Stefan -> nab's qemu vhost-scsi tree here:
http://git.kernel.org/?p=virt/kvm/nab/qemu-kvm.git;a=shortlog;h=refs/heads/vhost-scsi
--
Changelog v4 -> v5:
Expose ABI version via VHOST_SCSI_GET_ABI_VERSION + use Rev 0 as
starting point for v3.6-rc code (Stefan + ALiguori + nab)
Convert vhost_scsi_handle_vq() to vq_err() (nab + MST)
Minor style fixes from checkpatch (nab)
Changelog v3 -> v4:
Rename vhost_vring_target -> vhost_scsi_target (mst + nab)
Use TRANSPORT_IQN_LEN in vhost_scsi_target->vhost_wwpn[] def (nab)
Move back to drivers/vhost/, and just use drivers/vhost/Kconfig.tcm (mst)
Move TCM_VHOST related ioctl defines from include/linux/vhost.h ->
drivers/vhost/tcm_vhost.h as requested by MST (nab)
Move Kbuild.tcm include from drivers/staging -> drivers/vhost/, and
just use 'if STAGING' around 'source drivers/vhost/Kbuild.tcm'
Changelog v2 -> v3:
Unlock on error in tcm_vhost_drop_nexus() (DanC)
Fix strlen() doesn't count the terminator (DanC)
Call kfree() on an error path (DanC)
Convert tcm_vhost_write_pending to use target_execute_cmd (hch + nab)
Fix another strlen() off by one in tcm_vhost_make_tport (DanC)
Add option under drivers/staging/Kconfig, and move to drivers/vhost/tcm/
as requested by MST (nab)
Changelog v1 -> v2:
Fix tv_cmd completion -> release SGL memory leak (nab)
Fix sparse warnings for static variable usage ((Fengguang Wu)
Fix sparse warnings for min() typing + printk format specs (Fengguang Wu)
Convert to cmwq submission for I/O dispatch (nab + hch)
Changelog v0 -> v1:
Merge into single source + header file, and move to drivers/vhost/
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>
Cc: Zhi Yong Wu <wuzhy@cn.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/vhost/tcm_vhost.h b/drivers/vhost/tcm_vhost.h
new file mode 100644
index 0000000..c983ed2
--- /dev/null
+++ b/drivers/vhost/tcm_vhost.h
@@ -0,0 +1,101 @@
+#define TCM_VHOST_VERSION "v0.1"
+#define TCM_VHOST_NAMELEN 256
+#define TCM_VHOST_MAX_CDB_SIZE 32
+
+struct tcm_vhost_cmd {
+ /* Descriptor from vhost_get_vq_desc() for virt_queue segment */
+ int tvc_vq_desc;
+ /* The Tag from include/linux/virtio_scsi.h:struct virtio_scsi_cmd_req */
+ u64 tvc_tag;
+ /* The number of scatterlists associated with this cmd */
+ u32 tvc_sgl_count;
+ /* Saved unpacked SCSI LUN for tcm_vhost_submission_work() */
+ u32 tvc_lun;
+ /* Pointer to the SGL formatted memory from virtio-scsi */
+ struct scatterlist *tvc_sgl;
+ /* Pointer to response */
+ struct virtio_scsi_cmd_resp __user *tvc_resp;
+ /* Pointer to vhost_scsi for our device */
+ struct vhost_scsi *tvc_vhost;
+ /* The TCM I/O descriptor that is accessed via container_of() */
+ struct se_cmd tvc_se_cmd;
+ /* work item used for cmwq dispatch to tcm_vhost_submission_work() */
+ struct work_struct work;
+ /* Copy of the incoming SCSI command descriptor block (CDB) */
+ unsigned char tvc_cdb[TCM_VHOST_MAX_CDB_SIZE];
+ /* Sense buffer that will be mapped into outgoing status */
+ unsigned char tvc_sense_buf[TRANSPORT_SENSE_BUFFER];
+ /* Completed commands list, serviced from vhost worker thread */
+ struct list_head tvc_completion_list;
+};
+
+struct tcm_vhost_nexus {
+ /* Pointer to TCM session for I_T Nexus */
+ struct se_session *tvn_se_sess;
+};
+
+struct tcm_vhost_nacl {
+ /* Binary World Wide unique Port Name for Vhost Initiator port */
+ u64 iport_wwpn;
+ /* ASCII formatted WWPN for Sas Initiator port */
+ char iport_name[TCM_VHOST_NAMELEN];
+ /* Returned by tcm_vhost_make_nodeacl() */
+ struct se_node_acl se_node_acl;
+};
+
+struct tcm_vhost_tpg {
+ /* Vhost port target portal group tag for TCM */
+ u16 tport_tpgt;
+ /* Used to track number of TPG Port/Lun Links wrt to explict I_T Nexus shutdown */
+ atomic_t tv_tpg_port_count;
+ /* Used for vhost_scsi device reference to tpg_nexus */
+ atomic_t tv_tpg_vhost_count;
+ /* list for tcm_vhost_list */
+ struct list_head tv_tpg_list;
+ /* Used to protect access for tpg_nexus */
+ struct mutex tv_tpg_mutex;
+ /* Pointer to the TCM VHost I_T Nexus for this TPG endpoint */
+ struct tcm_vhost_nexus *tpg_nexus;
+ /* Pointer back to tcm_vhost_tport */
+ struct tcm_vhost_tport *tport;
+ /* Returned by tcm_vhost_make_tpg() */
+ struct se_portal_group se_tpg;
+};
+
+struct tcm_vhost_tport {
+ /* SCSI protocol the tport is providing */
+ u8 tport_proto_id;
+ /* Binary World Wide unique Port Name for Vhost Target port */
+ u64 tport_wwpn;
+ /* ASCII formatted WWPN for Vhost Target port */
+ char tport_name[TCM_VHOST_NAMELEN];
+ /* Returned by tcm_vhost_make_tport() */
+ struct se_wwn tport_wwn;
+};
+
+/*
+ * As per request from MST, keep TCM_VHOST related ioctl defines out of
+ * linux/vhost.h (user-space) for now..
+ */
+
+#include <linux/vhost.h>
+
+/*
+ * Used by QEMU userspace to ensure a consistent vhost-scsi ABI.
+ *
+ * ABI Rev 0: July 2012 version starting point for v3.6-rc merge candidate +
+ * RFC-v2 vhost-scsi userspace. Add GET_ABI_VERSION ioctl usage
+ */
+
+#define VHOST_SCSI_ABI_VERSION 0
+
+struct vhost_scsi_target {
+ int abi_version;
+ unsigned char vhost_wwpn[TRANSPORT_IQN_LEN];
+ unsigned short vhost_tpgt;
+};
+
+/* VHOST_SCSI specific defines */
+#define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target)
+#define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct vhost_scsi_target)
+#define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, struct vhost_scsi_target)