* [PATCH V4 1/4] Introduce xen-scsifront module
2014-08-08 7:43 Add XEN pvSCSI support jgross
@ 2014-08-08 7:43 ` jgross
2014-08-08 7:43 ` [PATCH V4 2/4] Introduce XEN scsiback module jgross
` (3 subsequent siblings)
4 siblings, 0 replies; 7+ messages in thread
From: jgross @ 2014-08-08 7:43 UTC (permalink / raw)
To: xen-devel, linux-scsi, target-devel, JBottomley, konrad.wilk, hch,
david.vrabel, JBeulich
Cc: Juergen Gross
From: Juergen Gross <jgross@suse.com>
Introduces the XEN pvSCSI frontend. With pvSCSI it is possible for a XEN domU
to issue SCSI commands to a SCSI LUN assigned to that domU. The SCSI commands
are passed to the pvSCSI backend in a driver domain (usually Dom0) which is
owner of the physical device. This allows e.g. to use SCSI tape drives in a
XEN domU.
The code is taken from the pvSCSI implementation in XEN done by Fujitsu based
on Linux kernel 2.6.18.
Changes from the original version are:
- port to upstream kernel
- put all code in just one source file
- move module to appropriate location in kernel tree
- adapt to Linux style guide
- some minor code simplifications
- replace constants with defines
- remove not used defines
- add support for larger SG lists by putting them in a granted page
Signed-off-by: Juergen Gross <jgross@suse.com>
Xen related parts
Acked-by: David Vrabel <david.vrabel@citrix.com>
---
drivers/scsi/Kconfig | 9 +
drivers/scsi/Makefile | 1 +
drivers/scsi/xen-scsifront.c | 1011 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 1021 insertions(+)
create mode 100644 drivers/scsi/xen-scsifront.c
diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index baca589..e860c16 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -611,6 +611,15 @@ config VMWARE_PVSCSI
To compile this driver as a module, choose M here: the
module will be called vmw_pvscsi.
+config XEN_SCSI_FRONTEND
+ tristate "XEN SCSI frontend driver"
+ depends on SCSI && XEN
+ help
+ The XEN SCSI frontend driver allows the kernel to access SCSI Devices
+ within another guest OS (usually Dom0).
+ Only needed if the kernel is running in a XEN guest and generic
+ SCSI access to a device is needed.
+
config HYPERV_STORAGE
tristate "Microsoft Hyper-V virtual storage driver"
depends on SCSI && HYPERV
diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
index e172d4f..a4ee9c5 100644
--- a/drivers/scsi/Makefile
+++ b/drivers/scsi/Makefile
@@ -144,6 +144,7 @@ obj-$(CONFIG_SCSI_ESAS2R) += esas2r/
obj-$(CONFIG_SCSI_PMCRAID) += pmcraid.o
obj-$(CONFIG_SCSI_VIRTIO) += virtio_scsi.o
obj-$(CONFIG_VMWARE_PVSCSI) += vmw_pvscsi.o
+obj-$(CONFIG_XEN_SCSI_FRONTEND) += xen-scsifront.o
obj-$(CONFIG_HYPERV_STORAGE) += hv_storvsc.o
obj-$(CONFIG_ARM) += arm/
diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c
new file mode 100644
index 0000000..7c60c68
--- /dev/null
+++ b/drivers/scsi/xen-scsifront.c
@@ -0,0 +1,1011 @@
+/*
+ * Xen SCSI frontend driver
+ *
+ * Copyright (c) 2008, FUJITSU Limited
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#define DEBUG
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/wait.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/sched.h>
+#include <linux/blkdev.h>
+#include <linux/pfn.h>
+#include <linux/slab.h>
+
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_host.h>
+
+#include <xen/xen.h>
+#include <xen/xenbus.h>
+#include <xen/grant_table.h>
+#include <xen/events.h>
+#include <xen/page.h>
+
+#include <xen/interface/grant_table.h>
+#include <xen/interface/io/vscsiif.h>
+#include <xen/interface/io/protocols.h>
+
+#include <asm/xen/hypervisor.h>
+
+
+#define GRANT_INVALID_REF 0
+
+#define VSCSIFRONT_OP_ADD_LUN 1
+#define VSCSIFRONT_OP_DEL_LUN 2
+
+#define DEFAULT_TASK_COMM_LEN TASK_COMM_LEN
+
+/* tuning point*/
+#define VSCSIIF_DEFAULT_CMD_PER_LUN 10
+#define VSCSIIF_MAX_TARGET 64
+#define VSCSIIF_MAX_LUN 255
+
+#define VSCSIIF_RING_SIZE __CONST_RING_SIZE(vscsiif, PAGE_SIZE)
+#define VSCSIIF_MAX_REQS VSCSIIF_RING_SIZE
+
+#define vscsiif_grants_sg(_sg) (PFN_UP((_sg) * \
+ sizeof(struct scsiif_request_segment)))
+
+struct vscsifrnt_shadow {
+ /* command between backend and frontend */
+ unsigned char act;
+ uint16_t rqid;
+
+ /* Number of pieces of scatter-gather */
+ unsigned int nr_grants;
+ struct scsiif_request_segment *sg;
+
+ /* do reset or abort function */
+ wait_queue_head_t wq_reset; /* reset work queue */
+ int wait_reset; /* reset work queue condition */
+ int32_t rslt_reset; /* reset response status */
+ /* (SUCESS or FAILED) */
+
+ /* requested struct scsi_cmnd is stored from kernel */
+ struct scsi_cmnd *sc;
+ int gref[vscsiif_grants_sg(SG_ALL) + SG_ALL];
+};
+
+struct vscsifrnt_info {
+ struct xenbus_device *dev;
+
+ struct Scsi_Host *host;
+ int host_active;
+
+ spinlock_t shadow_lock;
+ unsigned int evtchn;
+ unsigned int irq;
+
+ grant_ref_t ring_ref;
+ struct vscsiif_front_ring ring;
+ struct vscsiif_response ring_res;
+
+ unsigned long shadow_free;
+ struct vscsifrnt_shadow *shadow[VSCSIIF_MAX_REQS];
+
+ wait_queue_head_t wq_sync;
+ unsigned int waiting_sync:1;
+};
+
+#define DPRINTK(_f, _a...) \
+ pr_debug("(file=%s, line=%d) " _f, __FILE__ , __LINE__ , ## _a)
+
+#define PREFIX(lvl) KERN_##lvl "scsifront: "
+
+static void scsifront_wake_up(struct vscsifrnt_info *info)
+{
+ info->waiting_sync = 0;
+ wake_up(&info->wq_sync);
+}
+
+static int scsifront_get_rqid(struct vscsifrnt_info *info)
+{
+ unsigned long flags;
+ int free;
+
+ spin_lock_irqsave(&info->shadow_lock, flags);
+
+ free = find_first_bit(&info->shadow_free, VSCSIIF_MAX_REQS);
+ info->shadow_free &= ~(1UL << free);
+
+ spin_unlock_irqrestore(&info->shadow_lock, flags);
+
+ return free;
+}
+
+static int _scsifront_put_rqid(struct vscsifrnt_info *info, uint32_t id)
+{
+ info->shadow_free |= 1UL << id;
+ info->shadow[id] = NULL;
+
+ return (info->shadow_free == 1UL << id || info->waiting_sync);
+}
+
+static void scsifront_put_rqid(struct vscsifrnt_info *info, uint32_t id)
+{
+ unsigned long flags;
+ int was_empty;
+
+ spin_lock_irqsave(&info->shadow_lock, flags);
+ was_empty = _scsifront_put_rqid(info, id);
+ spin_unlock_irqrestore(&info->shadow_lock, flags);
+
+ if (was_empty)
+ scsifront_wake_up(info);
+}
+
+static struct vscsiif_request *scsifront_pre_req(struct vscsifrnt_info *info)
+{
+ struct vscsiif_front_ring *ring = &(info->ring);
+ struct vscsiif_request *ring_req;
+ uint32_t id;
+
+ id = scsifront_get_rqid(info); /* use id by response */
+ if (id >= VSCSIIF_MAX_REQS)
+ return NULL;
+
+ ring_req = RING_GET_REQUEST(&(info->ring), ring->req_prod_pvt);
+
+ ring->req_prod_pvt++;
+
+ ring_req->rqid = (uint16_t)id;
+
+ return ring_req;
+}
+
+static void scsifront_do_request(struct vscsifrnt_info *info)
+{
+ struct vscsiif_front_ring *ring = &(info->ring);
+ int notify;
+
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(ring, notify);
+ if (notify)
+ notify_remote_via_irq(info->irq);
+}
+
+static void scsifront_gnttab_done(struct vscsifrnt_info *info, uint32_t id)
+{
+ struct vscsifrnt_shadow *s = info->shadow[id];
+ int i;
+
+ if (s->sc->sc_data_direction == DMA_NONE)
+ return;
+
+ for (i = 0; i < s->nr_grants; i++) {
+ if (unlikely(gnttab_query_foreign_access(s->gref[i]) != 0)) {
+ shost_printk(PREFIX(ALERT), info->host,
+ "grant still in use by backend\n");
+ BUG();
+ }
+ gnttab_end_foreign_access(s->gref[i], 0, 0UL);
+ }
+
+ kfree(s->sg);
+}
+
+static void scsifront_cdb_cmd_done(struct vscsifrnt_info *info,
+ struct vscsiif_response *ring_res)
+{
+ struct scsi_cmnd *sc;
+ uint32_t id;
+ uint8_t sense_len;
+
+ id = ring_res->rqid;
+ sc = info->shadow[id]->sc;
+
+ BUG_ON(sc == NULL);
+
+ scsifront_gnttab_done(info, id);
+ scsifront_put_rqid(info, id);
+
+ sc->result = ring_res->rslt;
+ scsi_set_resid(sc, ring_res->residual_len);
+
+ sense_len = min_t(uint8_t, VSCSIIF_SENSE_BUFFERSIZE,
+ ring_res->sense_len);
+
+ if (sense_len)
+ memcpy(sc->sense_buffer, ring_res->sense_buffer, sense_len);
+
+ sc->scsi_done(sc);
+}
+
+static void scsifront_sync_cmd_done(struct vscsifrnt_info *info,
+ struct vscsiif_response *ring_res)
+{
+ uint16_t id = ring_res->rqid;
+ unsigned long flags;
+ struct vscsifrnt_shadow *shadow = info->shadow[id];
+ int was_empty;
+
+ spin_lock_irqsave(&info->shadow_lock, flags);
+ shadow->wait_reset = 1;
+ switch (shadow->rslt_reset) {
+ case 0:
+ shadow->rslt_reset = ring_res->rslt;
+ break;
+ case -1:
+ was_empty = _scsifront_put_rqid(info, id);
+ spin_unlock_irqrestore(&info->shadow_lock, flags);
+ kfree(shadow);
+ if (was_empty)
+ scsifront_wake_up(info);
+ return;
+ default:
+ shost_printk(PREFIX(ERR), info->host,
+ "bad reset state %d, possibly leaking %u\n",
+ shadow->rslt_reset, id);
+ break;
+ }
+ spin_unlock_irqrestore(&info->shadow_lock, flags);
+
+ wake_up(&shadow->wq_reset);
+}
+
+static int scsifront_cmd_done(struct vscsifrnt_info *info)
+{
+ struct vscsiif_response *ring_res;
+ RING_IDX i, rp;
+ int more_to_do = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(info->host->host_lock, flags);
+
+ rp = info->ring.sring->rsp_prod;
+ rmb(); /* ordering required respective to dom0 */
+ for (i = info->ring.rsp_cons; i != rp; i++) {
+
+ ring_res = RING_GET_RESPONSE(&info->ring, i);
+
+ if (info->shadow[ring_res->rqid]->act == VSCSIIF_ACT_SCSI_CDB)
+ scsifront_cdb_cmd_done(info, ring_res);
+ else
+ scsifront_sync_cmd_done(info, ring_res);
+ }
+
+ info->ring.rsp_cons = i;
+
+ if (i != info->ring.req_prod_pvt)
+ RING_FINAL_CHECK_FOR_RESPONSES(&info->ring, more_to_do);
+ else
+ info->ring.sring->rsp_event = i + 1;
+
+ info->waiting_sync = 0;
+
+ spin_unlock_irqrestore(info->host->host_lock, flags);
+
+ wake_up(&info->wq_sync);
+
+ return more_to_do;
+}
+
+static irqreturn_t scsifront_irq_fn(int irq, void *dev_id)
+{
+ struct vscsifrnt_info *info = dev_id;
+
+ while (scsifront_cmd_done(info))
+ /* Yield point for this unbounded loop. */
+ cond_resched();
+
+ return IRQ_HANDLED;
+}
+
+static int map_data_for_request(struct vscsifrnt_info *info,
+ struct scsi_cmnd *sc,
+ struct vscsiif_request *ring_req,
+ struct vscsifrnt_shadow *shadow)
+{
+ grant_ref_t gref_head;
+ struct page *page;
+ int err, ref, ref_cnt = 0;
+ int write = (sc->sc_data_direction == DMA_TO_DEVICE);
+ unsigned int i, off, len, bytes;
+ unsigned int data_len = scsi_bufflen(sc);
+ unsigned int data_grants = 0, seg_grants = 0;
+ struct scatterlist *sg;
+ unsigned long mfn;
+ struct scsiif_request_segment *seg;
+
+ ring_req->nr_segments = 0;
+ if (sc->sc_data_direction == DMA_NONE || !data_len)
+ return 0;
+
+ scsi_for_each_sg(sc, sg, scsi_sg_count(sc), i)
+ data_grants += PFN_UP(sg->offset + sg->length);
+
+ if (data_grants > VSCSIIF_SG_TABLESIZE) {
+ if (data_grants > info->host->sg_tablesize) {
+ shost_printk(PREFIX(ERR), info->host,
+ "Unable to map request_buffer for command!\n");
+ return -E2BIG;
+ }
+ seg_grants = vscsiif_grants_sg(data_grants);
+ shadow->sg = kcalloc(data_grants,
+ sizeof(struct scsiif_request_segment), GFP_NOIO);
+ if (!shadow->sg)
+ return -ENOMEM;
+ }
+ seg = shadow->sg ? : ring_req->seg;
+
+ err = gnttab_alloc_grant_references(seg_grants + data_grants,
+ &gref_head);
+ if (err) {
+ kfree(shadow->sg);
+ shost_printk(PREFIX(ERR), info->host,
+ "gnttab_alloc_grant_references() error\n");
+ return -ENOMEM;
+ }
+
+ if (seg_grants) {
+ page = virt_to_page(seg);
+ off = (unsigned long)seg & ~PAGE_MASK;
+ len = sizeof(struct scsiif_request_segment) * data_grants;
+ while (len > 0) {
+ bytes = min_t(unsigned int, len, PAGE_SIZE - off);
+
+ ref = gnttab_claim_grant_reference(&gref_head);
+ BUG_ON(ref == -ENOSPC);
+
+ mfn = pfn_to_mfn(page_to_pfn(page));
+ gnttab_grant_foreign_access_ref(ref,
+ info->dev->otherend_id, mfn, 1);
+ shadow->gref[ref_cnt] = ref;
+ ring_req->seg[ref_cnt].gref = ref;
+ ring_req->seg[ref_cnt].offset = (uint16_t)off;
+ ring_req->seg[ref_cnt].length = (uint16_t)bytes;
+
+ page++;
+ len -= bytes;
+ off = 0;
+ ref_cnt++;
+ }
+ BUG_ON(seg_grants < ref_cnt);
+ seg_grants = ref_cnt;
+ }
+
+ scsi_for_each_sg(sc, sg, scsi_sg_count(sc), i) {
+ page = sg_page(sg);
+ off = sg->offset;
+ len = sg->length;
+
+ while (len > 0 && data_len > 0) {
+ /*
+ * sg sends a scatterlist that is larger than
+ * the data_len it wants transferred for certain
+ * IO sizes
+ */
+ bytes = min_t(unsigned int, len, PAGE_SIZE - off);
+ bytes = min(bytes, data_len);
+
+ ref = gnttab_claim_grant_reference(&gref_head);
+ BUG_ON(ref == -ENOSPC);
+
+ mfn = pfn_to_mfn(page_to_pfn(page));
+ gnttab_grant_foreign_access_ref(ref,
+ info->dev->otherend_id, mfn, write);
+
+ shadow->gref[ref_cnt] = ref;
+ seg->gref = ref;
+ seg->offset = (uint16_t)off;
+ seg->length = (uint16_t)bytes;
+
+ page++;
+ seg++;
+ len -= bytes;
+ data_len -= bytes;
+ off = 0;
+ ref_cnt++;
+ }
+ }
+
+ if (seg_grants)
+ ring_req->nr_segments = VSCSIIF_SG_GRANT | seg_grants;
+ else
+ ring_req->nr_segments = (uint8_t)ref_cnt;
+ shadow->nr_grants = ref_cnt;
+
+ return 0;
+}
+
+static struct vscsiif_request *scsifront_command2ring(
+ struct vscsifrnt_info *info, struct scsi_cmnd *sc,
+ struct vscsifrnt_shadow *shadow)
+{
+ struct vscsiif_request *ring_req;
+
+ memset(shadow, 0, sizeof(*shadow));
+
+ ring_req = scsifront_pre_req(info);
+ if (!ring_req)
+ return NULL;
+
+ info->shadow[ring_req->rqid] = shadow;
+ shadow->rqid = ring_req->rqid;
+
+ ring_req->id = sc->device->id;
+ ring_req->lun = sc->device->lun;
+ ring_req->channel = sc->device->channel;
+ ring_req->cmd_len = sc->cmd_len;
+
+ BUG_ON(sc->cmd_len > VSCSIIF_MAX_COMMAND_SIZE);
+
+ if (sc->cmd_len)
+ memcpy(ring_req->cmnd, sc->cmnd, sc->cmd_len);
+ else
+ memset(ring_req->cmnd, 0, VSCSIIF_MAX_COMMAND_SIZE);
+
+ ring_req->sc_data_direction = (uint8_t)sc->sc_data_direction;
+ ring_req->timeout_per_command = sc->request->timeout / HZ;
+
+ return ring_req;
+}
+
+static int scsifront_queuecommand(struct Scsi_Host *shost,
+ struct scsi_cmnd *sc)
+{
+ struct vscsifrnt_info *info = shost_priv(shost);
+ struct vscsiif_request *ring_req;
+ struct vscsifrnt_shadow *shadow = scsi_cmd_priv(sc);
+ unsigned long flags;
+ int err;
+ uint16_t rqid;
+
+ spin_lock_irqsave(shost->host_lock, flags);
+ if (RING_FULL(&info->ring))
+ goto busy;
+
+ ring_req = scsifront_command2ring(info, sc, shadow);
+ if (!ring_req)
+ goto busy;
+
+ sc->result = 0;
+
+ rqid = ring_req->rqid;
+ ring_req->act = VSCSIIF_ACT_SCSI_CDB;
+
+ shadow->sc = sc;
+ shadow->act = VSCSIIF_ACT_SCSI_CDB;
+
+ err = map_data_for_request(info, sc, ring_req, shadow);
+ if (err < 0) {
+ DPRINTK("%s: err %d\n", __func__, err);
+ scsifront_put_rqid(info, rqid);
+ spin_unlock_irqrestore(shost->host_lock, flags);
+ if (err == -ENOMEM)
+ return SCSI_MLQUEUE_HOST_BUSY;
+ sc->result = DID_ERROR << 16;
+ sc->scsi_done(sc);
+ return 0;
+ }
+
+ scsifront_do_request(info);
+ spin_unlock_irqrestore(shost->host_lock, flags);
+
+ return 0;
+
+busy:
+ spin_unlock_irqrestore(shost->host_lock, flags);
+ DPRINTK("%s: busy\n", __func__);
+ return SCSI_MLQUEUE_HOST_BUSY;
+}
+
+static int scsifront_action_handler(struct scsi_cmnd *sc, uint8_t act)
+{
+ struct Scsi_Host *host = sc->device->host;
+ struct vscsifrnt_info *info = shost_priv(host);
+ struct vscsifrnt_shadow *shadow, *s = scsi_cmd_priv(sc);
+ struct vscsiif_request *ring_req;
+ int err = 0;
+
+ shadow = kmalloc(sizeof(*shadow), GFP_NOIO);
+ if (!shadow)
+ return FAILED;
+
+ for (;;) {
+ spin_lock_irq(host->host_lock);
+ if (!RING_FULL(&info->ring)) {
+ ring_req = scsifront_command2ring(info, sc, shadow);
+ if (ring_req)
+ break;
+ }
+ if (err) {
+ spin_unlock_irq(host->host_lock);
+ kfree(shadow);
+ return FAILED;
+ }
+ info->waiting_sync = 1;
+ spin_unlock_irq(host->host_lock);
+ err = wait_event_interruptible(info->wq_sync,
+ !info->waiting_sync);
+ spin_lock_irq(host->host_lock);
+ }
+
+ ring_req->act = act;
+ ring_req->ref_rqid = s->rqid;
+
+ shadow->act = act;
+ shadow->rslt_reset = 0;
+ init_waitqueue_head(&shadow->wq_reset);
+
+ ring_req->nr_segments = 0;
+
+ scsifront_do_request(info);
+
+ spin_unlock_irq(host->host_lock);
+ err = wait_event_interruptible(shadow->wq_reset, shadow->wait_reset);
+ spin_lock_irq(host->host_lock);
+
+ if (!err) {
+ err = shadow->rslt_reset;
+ scsifront_put_rqid(info, shadow->rqid);
+ kfree(shadow);
+ } else {
+ spin_lock(&info->shadow_lock);
+ shadow->rslt_reset = -1;
+ spin_unlock(&info->shadow_lock);
+ err = FAILED;
+ }
+
+ spin_unlock_irq(host->host_lock);
+ return err;
+}
+
+static int scsifront_eh_abort_handler(struct scsi_cmnd *sc)
+{
+ DPRINTK("%s\n", __func__);
+ return scsifront_action_handler(sc, VSCSIIF_ACT_SCSI_ABORT);
+}
+
+static int scsifront_dev_reset_handler(struct scsi_cmnd *sc)
+{
+ DPRINTK("%s\n", __func__);
+ return scsifront_action_handler(sc, VSCSIIF_ACT_SCSI_RESET);
+}
+
+static int scsifront_sdev_alloc(struct scsi_device *sdev)
+{
+ /* set hostdata to not NULL indicating new allocation */
+ sdev->hostdata = sdev;
+ return 0;
+}
+
+static struct scsi_host_template scsifront_sht = {
+ .module = THIS_MODULE,
+ .name = "Xen SCSI frontend driver",
+ .queuecommand = scsifront_queuecommand,
+ .eh_abort_handler = scsifront_eh_abort_handler,
+ .eh_device_reset_handler = scsifront_dev_reset_handler,
+ .slave_alloc = scsifront_sdev_alloc,
+ .cmd_per_lun = VSCSIIF_DEFAULT_CMD_PER_LUN,
+ .can_queue = VSCSIIF_MAX_REQS,
+ .this_id = -1,
+ .cmd_size = sizeof(struct vscsifrnt_shadow),
+ .sg_tablesize = VSCSIIF_SG_TABLESIZE,
+ .use_clustering = DISABLE_CLUSTERING,
+ .proc_name = "scsifront",
+};
+
+static void scsifront_free(struct vscsifrnt_info *info)
+{
+ if (info->host && info->host_active) {
+ /* Scsi_host not yet removed */
+ scsi_remove_host(info->host);
+ info->host_active = 0;
+ }
+
+ if (info->ring_ref != GRANT_INVALID_REF) {
+ gnttab_end_foreign_access(info->ring_ref, 0,
+ (unsigned long)info->ring.sring);
+ info->ring_ref = GRANT_INVALID_REF;
+ info->ring.sring = NULL;
+ }
+
+ if (info->irq)
+ unbind_from_irqhandler(info->irq, info);
+ info->irq = 0;
+ info->evtchn = 0;
+
+ if (info->host)
+ scsi_host_put(info->host);
+}
+
+static int scsifront_alloc_ring(struct vscsifrnt_info *info)
+{
+ struct xenbus_device *dev = info->dev;
+ struct vscsiif_sring *sring;
+ int err = -ENOMEM;
+
+ info->ring_ref = GRANT_INVALID_REF;
+
+ /***** Frontend to Backend ring start *****/
+ sring = (struct vscsiif_sring *) __get_free_page(GFP_KERNEL);
+ if (!sring) {
+ xenbus_dev_fatal(dev, err,
+ "fail to allocate shared ring (Front to Back)");
+ return err;
+ }
+ SHARED_RING_INIT(sring);
+ FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE);
+
+ err = xenbus_grant_ring(dev, virt_to_mfn(sring));
+ if (err < 0) {
+ free_page((unsigned long) sring);
+ info->ring.sring = NULL;
+ xenbus_dev_fatal(dev, err,
+ "fail to grant shared ring (Front to Back)");
+ goto free_sring;
+ }
+ info->ring_ref = err;
+
+ err = xenbus_alloc_evtchn(dev, &info->evtchn);
+ if (err)
+ goto free_sring;
+
+ err = bind_evtchn_to_irq(info->evtchn);
+ if (err <= 0) {
+ xenbus_dev_fatal(dev, err, "bind_evtchn_to_irq");
+ goto free_sring;
+ }
+
+ info->irq = err;
+
+ err = request_threaded_irq(info->irq, NULL, scsifront_irq_fn,
+ IRQF_ONESHOT, "scsifront", info);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "request_threaded_irq");
+ goto free_sring;
+ }
+
+ return 0;
+
+/* free resource */
+free_sring:
+ scsifront_free(info);
+
+ return err;
+}
+
+static int scsifront_init_ring(struct vscsifrnt_info *info)
+{
+ struct xenbus_device *dev = info->dev;
+ struct xenbus_transaction xbt;
+ int err;
+
+ DPRINTK("%s\n", __func__);
+
+ err = scsifront_alloc_ring(info);
+ if (err)
+ return err;
+ DPRINTK("%u %u\n", info->ring_ref, info->evtchn);
+
+again:
+ err = xenbus_transaction_start(&xbt);
+ if (err)
+ xenbus_dev_fatal(dev, err, "starting transaction");
+
+ err = xenbus_printf(xbt, dev->nodename, "ring-ref", "%u",
+ info->ring_ref);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "%s", "writing ring-ref");
+ goto fail;
+ }
+
+ err = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
+ info->evtchn);
+
+ if (err) {
+ xenbus_dev_fatal(dev, err, "%s", "writing event-channel");
+ goto fail;
+ }
+
+ err = xenbus_transaction_end(xbt, 0);
+ if (err) {
+ if (err == -EAGAIN)
+ goto again;
+ xenbus_dev_fatal(dev, err, "completing transaction");
+ goto free_sring;
+ }
+
+ return 0;
+
+fail:
+ xenbus_transaction_end(xbt, 1);
+free_sring:
+ /* free resource */
+ scsifront_free(info);
+
+ return err;
+}
+
+
+static int scsifront_probe(struct xenbus_device *dev,
+ const struct xenbus_device_id *id)
+{
+ struct vscsifrnt_info *info;
+ struct Scsi_Host *host;
+ int err = -ENOMEM;
+ char name[DEFAULT_TASK_COMM_LEN];
+
+ host = scsi_host_alloc(&scsifront_sht, sizeof(*info));
+ if (!host) {
+ xenbus_dev_fatal(dev, err, "fail to allocate scsi host");
+ return err;
+ }
+ info = (struct vscsifrnt_info *)host->hostdata;
+
+ dev_set_drvdata(&dev->dev, info);
+ info->dev = dev;
+
+ info->shadow_free = (1UL << VSCSIIF_MAX_REQS) - 1;
+
+ err = scsifront_init_ring(info);
+ if (err) {
+ scsi_host_put(host);
+ return err;
+ }
+
+ init_waitqueue_head(&info->wq_sync);
+ spin_lock_init(&info->shadow_lock);
+
+ snprintf(name, DEFAULT_TASK_COMM_LEN, "vscsiif.%d", host->host_no);
+
+ host->max_id = VSCSIIF_MAX_TARGET;
+ host->max_channel = 0;
+ host->max_lun = VSCSIIF_MAX_LUN;
+ host->max_sectors = (host->sg_tablesize - 1) * PAGE_SIZE / 512;
+ host->max_cmd_len = VSCSIIF_MAX_COMMAND_SIZE;
+
+ err = scsi_add_host(host, &dev->dev);
+ if (err) {
+ dev_err(&dev->dev, "fail to add scsi host %d\n", err);
+ goto free_sring;
+ }
+ info->host = host;
+ info->host_active = 1;
+
+ xenbus_switch_state(dev, XenbusStateInitialised);
+
+ return 0;
+
+free_sring:
+ /* free resource */
+ scsifront_free(info);
+ scsi_host_put(host);
+ return err;
+}
+
+static int scsifront_remove(struct xenbus_device *dev)
+{
+ struct vscsifrnt_info *info = dev_get_drvdata(&dev->dev);
+
+ DPRINTK("%s: %s removed\n", __func__, dev->nodename);
+
+ scsifront_free(info);
+
+ return 0;
+}
+
+static void scsifront_disconnect(struct vscsifrnt_info *info)
+{
+ struct xenbus_device *dev = info->dev;
+ struct Scsi_Host *host = info->host;
+
+ DPRINTK("%s: %s disconnect\n", __func__, dev->nodename);
+
+ /*
+ * When this function is executed, all devices of
+ * Frontend have been deleted.
+ * Therefore, it need not block I/O before remove_host.
+ */
+
+ if (info->host_active)
+ scsi_remove_host(host);
+ info->host_active = 0;
+
+ xenbus_frontend_closed(dev);
+}
+
+static void scsifront_do_lun_hotplug(struct vscsifrnt_info *info, int op)
+{
+ struct xenbus_device *dev = info->dev;
+ int i, err = 0;
+ char str[64], state_str[64];
+ char **dir;
+ unsigned int dir_n = 0;
+ unsigned int device_state;
+ unsigned int hst, chn, tgt, lun;
+ struct scsi_device *sdev;
+
+ dir = xenbus_directory(XBT_NIL, dev->otherend, "vscsi-devs", &dir_n);
+ if (IS_ERR(dir))
+ return;
+
+ for (i = 0; i < dir_n; i++) {
+ /* read status */
+ snprintf(str, sizeof(str), "vscsi-devs/%s/state", dir[i]);
+ err = xenbus_scanf(XBT_NIL, dev->otherend, str, "%u",
+ &device_state);
+ if (XENBUS_EXIST_ERR(err))
+ continue;
+
+ /* virtual SCSI device */
+ snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", dir[i]);
+ err = xenbus_scanf(XBT_NIL, dev->otherend, str,
+ "%u:%u:%u:%u", &hst, &chn, &tgt, &lun);
+ if (XENBUS_EXIST_ERR(err))
+ continue;
+
+ /* front device state path */
+ snprintf(state_str, sizeof(state_str), "vscsi-devs/%s/state",
+ dir[i]);
+
+ switch (op) {
+ case VSCSIFRONT_OP_ADD_LUN:
+ if (device_state == XenbusStateInitialised) {
+ sdev = __scsi_add_device(info->host, chn, tgt,
+ lun, NULL);
+ err = (IS_ERR(sdev) || !sdev->hostdata);
+ if (!IS_ERR(sdev)) {
+ sdev->hostdata = NULL;
+ scsi_device_put(sdev);
+ }
+
+ if (err) {
+ dev_err(&dev->dev,
+ "Device already in use.\n");
+ xenbus_printf(XBT_NIL, dev->nodename,
+ state_str, "%d",
+ XenbusStateClosed);
+ } else {
+ xenbus_printf(XBT_NIL, dev->nodename,
+ state_str, "%d",
+ XenbusStateConnected);
+ }
+ }
+ break;
+ case VSCSIFRONT_OP_DEL_LUN:
+ if (device_state == XenbusStateClosing) {
+ sdev = scsi_device_lookup(info->host, chn, tgt,
+ lun);
+ if (sdev) {
+ scsi_remove_device(sdev);
+ scsi_device_put(sdev);
+ xenbus_printf(XBT_NIL, dev->nodename,
+ state_str, "%d",
+ XenbusStateClosed);
+ }
+ }
+ break;
+ default:
+ break;
+ }
+ }
+
+ kfree(dir);
+}
+
+static void scsifront_read_backend_params(struct xenbus_device *dev,
+ struct vscsifrnt_info *info)
+{
+ unsigned int sg_grant;
+ int ret;
+ struct Scsi_Host *host = info->host;
+
+ ret = xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg-grant", "%u",
+ &sg_grant);
+ if (ret == 1 && sg_grant) {
+ sg_grant = min_t(unsigned int, sg_grant, SG_ALL);
+ host->sg_tablesize = min_t(unsigned int, sg_grant,
+ VSCSIIF_SG_TABLESIZE * PAGE_SIZE /
+ sizeof(struct scsiif_request_segment));
+ dev_info(&dev->dev, "using up to %d SG entries\n",
+ host->sg_tablesize);
+ host->max_sectors = (host->sg_tablesize - 1) * PAGE_SIZE / 512;
+ }
+}
+
+static void scsifront_backend_changed(struct xenbus_device *dev,
+ enum xenbus_state backend_state)
+{
+ struct vscsifrnt_info *info = dev_get_drvdata(&dev->dev);
+
+ DPRINTK("%p %u %u\n", dev, dev->state, backend_state);
+
+ switch (backend_state) {
+ case XenbusStateUnknown:
+ case XenbusStateInitialising:
+ case XenbusStateInitWait:
+ case XenbusStateInitialised:
+ break;
+
+ case XenbusStateConnected:
+ scsifront_read_backend_params(dev, info);
+ if (xenbus_read_driver_state(dev->nodename) ==
+ XenbusStateInitialised) {
+ scsifront_do_lun_hotplug(info, VSCSIFRONT_OP_ADD_LUN);
+ }
+
+ if (dev->state != XenbusStateConnected)
+ xenbus_switch_state(dev, XenbusStateConnected);
+ break;
+
+ case XenbusStateClosed:
+ if (dev->state == XenbusStateClosed)
+ break;
+ /* Missed the backend's Closing state -- fallthrough */
+ case XenbusStateClosing:
+ scsifront_disconnect(info);
+ break;
+
+ case XenbusStateReconfiguring:
+ scsifront_do_lun_hotplug(info, VSCSIFRONT_OP_DEL_LUN);
+ xenbus_switch_state(dev, XenbusStateReconfiguring);
+ break;
+
+ case XenbusStateReconfigured:
+ scsifront_do_lun_hotplug(info, VSCSIFRONT_OP_ADD_LUN);
+ xenbus_switch_state(dev, XenbusStateConnected);
+ break;
+ }
+}
+
+static const struct xenbus_device_id scsifront_ids[] = {
+ { "vscsi" },
+ { "" }
+};
+
+static DEFINE_XENBUS_DRIVER(scsifront, ,
+ .probe = scsifront_probe,
+ .remove = scsifront_remove,
+ .otherend_changed = scsifront_backend_changed,
+);
+
+static int __init scsifront_init(void)
+{
+ if (!xen_domain())
+ return -ENODEV;
+
+ return xenbus_register_frontend(&scsifront_driver);
+}
+module_init(scsifront_init);
+
+static void __exit scsifront_exit(void)
+{
+ xenbus_unregister_driver(&scsifront_driver);
+}
+module_exit(scsifront_exit);
+
+MODULE_DESCRIPTION("Xen SCSI frontend driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("xen:vscsi");
--
1.8.4.5
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH V4 2/4] Introduce XEN scsiback module
2014-08-08 7:43 Add XEN pvSCSI support jgross
2014-08-08 7:43 ` [PATCH V4 1/4] Introduce xen-scsifront module jgross
@ 2014-08-08 7:43 ` jgross
2014-08-08 7:43 ` [PATCH V4 3/4] add xen pvscsi maintainer jgross
` (2 subsequent siblings)
4 siblings, 0 replies; 7+ messages in thread
From: jgross @ 2014-08-08 7:43 UTC (permalink / raw)
To: xen-devel, linux-scsi, target-devel, JBottomley, konrad.wilk, hch,
david.vrabel, JBeulich
Cc: Juergen Gross
From: Juergen Gross <jgross@suse.com>
Introduces the XEN pvSCSI backend. With pvSCSI it is possible for a XEN domU
to issue SCSI commands to a SCSI LUN assigned to that domU. The SCSI commands
are passed to the pvSCSI backend in a driver domain (usually Dom0) which is
owner of the physical device. This allows e.g. to use SCSI tape drives in a
XEN domU.
The code is taken from the pvSCSI implementation in XEN done by Fujitsu based
on Linux kernel 2.6.18.
Changes from the original version are:
- port to upstream kernel
- put all code in just one source file
- adapt to Linux style guide
- use target core infrastructure instead doing pure pass-through
- enable module unloading
- support SG-list in grant page(s)
- support task abort
- remove redundant struct backend
- allocate resources dynamically
- correct minor error in scsiback_fast_flush_area
- free allocated resources in case of error during I/O preparation
- remove CDB emulation, now handled by target core infrastructure
Signed-off-by: Juergen Gross <jgross@suse.com>
Xen related parts
Acked-by: David Vrabel <david.vrabel@citrix.com>
---
drivers/xen/Kconfig | 9 +
drivers/xen/Makefile | 1 +
drivers/xen/xen-scsiback.c | 2282 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 2292 insertions(+)
create mode 100644 drivers/xen/xen-scsiback.c
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 38fb36e..42fb963 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -172,6 +172,15 @@ config XEN_PCIDEV_BACKEND
If in doubt, say m.
+config XEN_SCSI_BACKEND
+ tristate "XEN SCSI backend driver"
+ depends on XEN && XEN_BACKEND && TARGET_CORE
+ help
+ The SCSI backend driver allows the kernel to export its SCSI Devices
+ to other guests via a high-performance shared-memory interface.
+ Only needed for systems running as XEN driver domains (e.g. Dom0) and
+ if guests need generic access to SCSI devices.
+
config XEN_PRIVCMD
tristate
depends on XEN
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index 45e00af..b42ee75 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -33,6 +33,7 @@ obj-$(CONFIG_XEN_STUB) += xen-stub.o
obj-$(CONFIG_XEN_ACPI_HOTPLUG_MEMORY) += xen-acpi-memhotplug.o
obj-$(CONFIG_XEN_ACPI_HOTPLUG_CPU) += xen-acpi-cpuhotplug.o
obj-$(CONFIG_XEN_ACPI_PROCESSOR) += xen-acpi-processor.o
+obj-$(CONFIG_XEN_SCSI_BACKEND) += xen-scsiback.o
xen-evtchn-y := evtchn.o
xen-gntdev-y := gntdev.o
xen-gntalloc-y := gntalloc.o
diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
new file mode 100644
index 0000000..4a0d6e3
--- /dev/null
+++ b/drivers/xen/xen-scsiback.c
@@ -0,0 +1,2282 @@
+/*
+ * Xen SCSI backend driver
+ *
+ * Copyright (c) 2008, FUJITSU Limited
+ *
+ * Based on the blkback driver code.
+ * Adaption to kernel taget core infrastructure taken from vhost/scsi.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <stdarg.h>
+
+#include <linux/module.h>
+#include <linux/utsname.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/list.h>
+#include <linux/gfp.h>
+#include <linux/kthread.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/configfs.h>
+
+#include <generated/utsrelease.h>
+
+#include <scsi/scsi_dbg.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_tcq.h>
+
+#include <target/target_core_base.h>
+#include <target/target_core_fabric.h>
+#include <target/target_core_configfs.h>
+#include <target/target_core_fabric_configfs.h>
+
+#include <asm/hypervisor.h>
+
+#include <xen/xen.h>
+#include <xen/balloon.h>
+#include <xen/events.h>
+#include <xen/xenbus.h>
+#include <xen/grant_table.h>
+#include <xen/page.h>
+
+#include <xen/interface/grant_table.h>
+#include <xen/interface/io/vscsiif.h>
+
+#define DPRINTK(_f, _a...) \
+ pr_debug("(file=%s, line=%d) " _f, __FILE__ , __LINE__ , ## _a)
+
+#define VSCSI_VERSION "v0.1"
+#define VSCSI_NAMELEN 32
+
+struct ids_tuple {
+ unsigned int hst; /* host */
+ unsigned int chn; /* channel */
+ unsigned int tgt; /* target */
+ unsigned int lun; /* LUN */
+};
+
+struct v2p_entry {
+ struct ids_tuple v; /* translate from */
+ struct scsiback_tpg *tpg; /* translate to */
+ unsigned int lun;
+ struct kref kref;
+ struct list_head l;
+};
+
+struct vscsibk_info {
+ struct xenbus_device *dev;
+
+ domid_t domid;
+ unsigned int evtchn;
+ unsigned int irq;
+
+ struct vscsiif_back_ring ring;
+
+ spinlock_t ring_lock;
+ atomic_t nr_unreplied_reqs;
+
+ spinlock_t v2p_lock;
+ struct list_head v2p_entry_lists;
+
+ struct task_struct *kthread;
+ wait_queue_head_t waiting_to_free;
+ wait_queue_head_t wq;
+ wait_queue_head_t shutdown_wq;
+ unsigned int waiting_reqs;
+};
+
+/* theoretical maximum of grants for one request */
+#define VSCSI_MAX_GRANTS (SG_ALL + VSCSIIF_SG_TABLESIZE)
+
+/*
+ * VSCSI_GRANT_BATCH is the maximum number of grants to be processed in one
+ * call to map/unmap grants. Don't choose it too large, as there are arrays
+ * with VSCSI_GRANT_BATCH elements allocated on the stack.
+ */
+#define VSCSI_GRANT_BATCH 16
+
+struct vscsibk_pend {
+ uint16_t rqid;
+
+ uint8_t cmnd[VSCSIIF_MAX_COMMAND_SIZE];
+ uint8_t cmd_len;
+
+ uint8_t sc_data_direction;
+ uint16_t n_sg; /* real length of SG list */
+ uint16_t n_grants; /* SG pages and potentially SG list */
+ uint32_t data_len;
+ uint32_t result;
+
+ struct vscsibk_info *info;
+ struct v2p_entry *v2p;
+ struct scatterlist *sgl;
+
+ uint8_t sense_buffer[VSCSIIF_SENSE_BUFFERSIZE];
+
+ grant_handle_t grant_handles[VSCSI_MAX_GRANTS];
+ struct page *pages[VSCSI_MAX_GRANTS];
+
+ struct se_cmd se_cmd;
+};
+
+struct scsiback_tmr {
+ atomic_t tmr_complete;
+ wait_queue_head_t tmr_wait;
+};
+
+struct vscsibk_emulate {
+ void (*pre_function)(struct vscsibk_pend *, void *);
+ void (*post_function)(struct vscsibk_pend *, void *);
+};
+
+struct scsiback_nexus {
+ /* Pointer to TCM session for I_T Nexus */
+ struct se_session *tvn_se_sess;
+};
+
+struct scsiback_nacl {
+ /* Binary World Wide unique Port Name for pvscsi Initiator port */
+ u64 iport_wwpn;
+ /* ASCII formatted WWPN for Sas Initiator port */
+ char iport_name[VSCSI_NAMELEN];
+ /* Returned by scsiback_make_nodeacl() */
+ struct se_node_acl se_node_acl;
+};
+
+struct scsiback_tport {
+ /* SCSI protocol the tport is providing */
+ u8 tport_proto_id;
+ /* Binary World Wide unique Port Name for pvscsi Target port */
+ u64 tport_wwpn;
+ /* ASCII formatted WWPN for pvscsi Target port */
+ char tport_name[VSCSI_NAMELEN];
+ /* Returned by scsiback_make_tport() */
+ struct se_wwn tport_wwn;
+};
+
+struct scsiback_tpg {
+ /* scsiback port target portal group tag for TCM */
+ u16 tport_tpgt;
+ /* track number of TPG Port/Lun Links wrt explicit I_T Nexus shutdown */
+ int tv_tpg_port_count;
+ /* xen-pvscsi references to tpg_nexus, protected by tv_tpg_mutex */
+ int tv_tpg_fe_count;
+ /* list for scsiback_list */
+ struct list_head tv_tpg_list;
+ /* Used to protect access for tpg_nexus */
+ struct mutex tv_tpg_mutex;
+ /* Pointer to the TCM pvscsi I_T Nexus for this TPG endpoint */
+ struct scsiback_nexus *tpg_nexus;
+ /* Pointer back to scsiback_tport */
+ struct scsiback_tport *tport;
+ /* Returned by scsiback_make_tpg() */
+ struct se_portal_group se_tpg;
+ /* alias used in xenstore */
+ char param_alias[VSCSI_NAMELEN];
+ /* list of info structures related to this target portal group */
+ struct list_head info_list;
+};
+
+#define scsiback_get(_b) (atomic_inc(&(_b)->nr_unreplied_reqs))
+#define scsiback_put(_b) \
+ do { \
+ if (atomic_dec_and_test(&(_b)->nr_unreplied_reqs)) \
+ wake_up(&(_b)->waiting_to_free);\
+ } while (0)
+
+#define SCSIBACK_INVALID_HANDLE (~0)
+
+static bool log_print_stat;
+module_param(log_print_stat, bool, 0644);
+
+static int scsiback_max_buffer_pages = 1024;
+module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644);
+MODULE_PARM_DESC(max_buffer_pages,
+"Maximum number of free pages to keep in backend buffer");
+
+static struct kmem_cache *scsiback_cachep;
+static DEFINE_SPINLOCK(free_pages_lock);
+static int free_pages_num;
+static LIST_HEAD(scsiback_free_pages);
+
+/* Global spinlock to protect scsiback TPG list */
+static DEFINE_MUTEX(scsiback_mutex);
+static LIST_HEAD(scsiback_list);
+
+/* Local pointer to allocated TCM configfs fabric module */
+static struct target_fabric_configfs *scsiback_fabric_configfs;
+
+static void put_free_pages(struct page **page, int num)
+{
+ unsigned long flags;
+ int i = free_pages_num + num, n = num;
+
+ if (num == 0)
+ return;
+ if (i > scsiback_max_buffer_pages) {
+ n = min(num, i - scsiback_max_buffer_pages);
+ free_xenballooned_pages(n, page + num - n);
+ n = num - n;
+ }
+ spin_lock_irqsave(&free_pages_lock, flags);
+ for (i = 0; i < n; i++)
+ list_add(&page[i]->lru, &scsiback_free_pages);
+ free_pages_num += n;
+ spin_unlock_irqrestore(&free_pages_lock, flags);
+}
+
+static int get_free_page(struct page **page)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&free_pages_lock, flags);
+ if (list_empty(&scsiback_free_pages)) {
+ spin_unlock_irqrestore(&free_pages_lock, flags);
+ return alloc_xenballooned_pages(1, page, false);
+ }
+ page[0] = list_first_entry(&scsiback_free_pages, struct page, lru);
+ list_del(&page[0]->lru);
+ free_pages_num--;
+ spin_unlock_irqrestore(&free_pages_lock, flags);
+ return 0;
+}
+
+static unsigned long vaddr_page(struct page *page)
+{
+ unsigned long pfn = page_to_pfn(page);
+
+ return (unsigned long)pfn_to_kaddr(pfn);
+}
+
+static unsigned long vaddr(struct vscsibk_pend *req, int seg)
+{
+ return vaddr_page(req->pages[seg]);
+}
+
+static void scsiback_print_status(char *sense_buffer, int errors,
+ struct vscsibk_pend *pending_req)
+{
+ struct scsiback_tpg *tpg = pending_req->v2p->tpg;
+
+ pr_err("xen-pvscsi[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x drv=%02x\n",
+ tpg->tport->tport_name, pending_req->v2p->lun,
+ pending_req->cmnd[0], status_byte(errors), msg_byte(errors),
+ host_byte(errors), driver_byte(errors));
+
+ if (CHECK_CONDITION & status_byte(errors))
+ __scsi_print_sense("xen-pvscsi", sense_buffer,
+ SCSI_SENSE_BUFFERSIZE);
+}
+
+static void scsiback_fast_flush_area(struct vscsibk_pend *req)
+{
+ struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH];
+ struct page *pages[VSCSI_GRANT_BATCH];
+ unsigned int i, invcount = 0;
+ grant_handle_t handle;
+ int err;
+
+ kfree(req->sgl);
+ req->sgl = NULL;
+ req->n_sg = 0;
+
+ if (!req->n_grants)
+ return;
+
+ for (i = 0; i < req->n_grants; i++) {
+ handle = req->grant_handles[i];
+ if (handle == SCSIBACK_INVALID_HANDLE)
+ continue;
+ gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i),
+ GNTMAP_host_map, handle);
+ req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
+ pages[invcount] = req->pages[i];
+ put_page(pages[invcount]);
+ invcount++;
+ if (invcount < VSCSI_GRANT_BATCH)
+ continue;
+ err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
+ BUG_ON(err);
+ invcount = 0;
+ }
+
+ if (invcount) {
+ err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
+ BUG_ON(err);
+ }
+
+ put_free_pages(req->pages, req->n_grants);
+ req->n_grants = 0;
+}
+
+static void scsiback_free_translation_entry(struct kref *kref)
+{
+ struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref);
+ struct scsiback_tpg *tpg = entry->tpg;
+
+ mutex_lock(&tpg->tv_tpg_mutex);
+ tpg->tv_tpg_fe_count--;
+ mutex_unlock(&tpg->tv_tpg_mutex);
+
+ kfree(entry);
+}
+
+static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result,
+ uint32_t resid, struct vscsibk_pend *pending_req)
+{
+ struct vscsiif_response *ring_res;
+ struct vscsibk_info *info = pending_req->info;
+ int notify;
+ struct scsi_sense_hdr sshdr;
+ unsigned long flags;
+ unsigned len;
+
+ spin_lock_irqsave(&info->ring_lock, flags);
+
+ ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt);
+ info->ring.rsp_prod_pvt++;
+
+ ring_res->rslt = result;
+ ring_res->rqid = pending_req->rqid;
+
+ if (sense_buffer != NULL &&
+ scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE,
+ &sshdr)) {
+ len = min_t(unsigned, 8 + sense_buffer[7],
+ VSCSIIF_SENSE_BUFFERSIZE);
+ memcpy(ring_res->sense_buffer, sense_buffer, len);
+ ring_res->sense_len = len;
+ } else {
+ ring_res->sense_len = 0;
+ }
+
+ ring_res->residual_len = resid;
+
+ RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify);
+ spin_unlock_irqrestore(&info->ring_lock, flags);
+
+ if (notify)
+ notify_remote_via_irq(info->irq);
+
+ if (pending_req->v2p)
+ kref_put(&pending_req->v2p->kref,
+ scsiback_free_translation_entry);
+
+ kmem_cache_free(scsiback_cachep, pending_req);
+}
+
+static void scsiback_cmd_done(struct vscsibk_pend *pending_req)
+{
+ struct vscsibk_info *info = pending_req->info;
+ unsigned char *sense_buffer;
+ unsigned int resid;
+ int errors;
+
+ sense_buffer = pending_req->sense_buffer;
+ resid = pending_req->se_cmd.residual_count;
+ errors = pending_req->result;
+
+ if (errors && log_print_stat)
+ scsiback_print_status(sense_buffer, errors, pending_req);
+
+ scsiback_fast_flush_area(pending_req);
+ scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req);
+ scsiback_put(info);
+
+ transport_generic_free_cmd(&pending_req->se_cmd, 0);
+}
+
+static void scsiback_cmd_exec(struct vscsibk_pend *pending_req)
+{
+ struct se_cmd *se_cmd = &pending_req->se_cmd;
+ struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess;
+ int rc;
+
+ memset(pending_req->sense_buffer, 0, VSCSIIF_SENSE_BUFFERSIZE);
+
+ memset(se_cmd, 0, sizeof(*se_cmd));
+ se_cmd->prot_pto = true;
+
+ scsiback_get(pending_req->info);
+ rc = target_submit_cmd_map_sgls(se_cmd, sess, pending_req->cmnd,
+ pending_req->sense_buffer, pending_req->v2p->lun,
+ pending_req->data_len, 0,
+ pending_req->sc_data_direction, 0,
+ pending_req->sgl, pending_req->n_sg,
+ NULL, 0, NULL, 0);
+ if (rc < 0) {
+ transport_send_check_condition_and_sense(se_cmd,
+ TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
+ transport_generic_free_cmd(se_cmd, 0);
+ }
+}
+
+static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map,
+ struct page **pg, grant_handle_t *grant, int cnt)
+{
+ int err, i;
+
+ if (!cnt)
+ return 0;
+
+ err = gnttab_map_refs(map, NULL, pg, cnt);
+ BUG_ON(err);
+ for (i = 0; i < cnt; i++) {
+ if (unlikely(map[i].status != GNTST_okay)) {
+ pr_err("xen-pvscsi: invalid buffer -- could not remap it\n");
+ map[i].handle = SCSIBACK_INVALID_HANDLE;
+ err = -ENOMEM;
+ } else {
+ get_page(pg[i]);
+ }
+ grant[i] = map[i].handle;
+ }
+ return err;
+}
+
+static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req,
+ struct scsiif_request_segment *seg, struct page **pg,
+ grant_handle_t *grant, int cnt, u32 flags)
+{
+ int mapcount = 0, i, err = 0;
+ struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH];
+ struct vscsibk_info *info = pending_req->info;
+
+ for (i = 0; i < cnt; i++) {
+ if (get_free_page(pg + mapcount)) {
+ put_free_pages(pg, mapcount);
+ pr_err("xen-pvscsi: no grant page\n");
+ return -ENOMEM;
+ }
+ gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]),
+ flags, seg[i].gref, info->domid);
+ mapcount++;
+ if (mapcount < VSCSI_GRANT_BATCH)
+ continue;
+ err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
+ pg += mapcount;
+ grant += mapcount;
+ pending_req->n_grants += mapcount;
+ if (err)
+ return err;
+ mapcount = 0;
+ }
+ err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
+ pending_req->n_grants += mapcount;
+ return err;
+}
+
+static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req,
+ struct vscsibk_pend *pending_req)
+{
+ u32 flags;
+ int i, err, n_segs, i_seg = 0;
+ struct page **pg;
+ struct scsiif_request_segment *seg;
+ unsigned long end_seg = 0;
+ unsigned int nr_segments = (unsigned int)ring_req->nr_segments;
+ unsigned int nr_sgl = 0;
+ struct scatterlist *sg;
+ grant_handle_t *grant;
+
+ pending_req->n_sg = 0;
+ pending_req->n_grants = 0;
+ pending_req->data_len = 0;
+
+ nr_segments &= ~VSCSIIF_SG_GRANT;
+ if (!nr_segments)
+ return 0;
+
+ if (nr_segments > VSCSIIF_SG_TABLESIZE) {
+ DPRINTK("xen-pvscsi: invalid parameter nr_seg = %d\n",
+ ring_req->nr_segments);
+ return -EINVAL;
+ }
+
+ if (ring_req->nr_segments & VSCSIIF_SG_GRANT) {
+ err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg,
+ pending_req->pages, pending_req->grant_handles,
+ nr_segments, GNTMAP_host_map | GNTMAP_readonly);
+ if (err)
+ return err;
+ nr_sgl = nr_segments;
+ nr_segments = 0;
+ for (i = 0; i < nr_sgl; i++) {
+ n_segs = ring_req->seg[i].length /
+ sizeof(struct scsiif_request_segment);
+ if ((unsigned)ring_req->seg[i].offset +
+ (unsigned)ring_req->seg[i].length > PAGE_SIZE ||
+ n_segs * sizeof(struct scsiif_request_segment) !=
+ ring_req->seg[i].length)
+ return -EINVAL;
+ nr_segments += n_segs;
+ }
+ if (nr_segments > SG_ALL) {
+ DPRINTK("xen-pvscsi: invalid nr_seg = %d\n",
+ nr_segments);
+ return -EINVAL;
+ }
+ }
+
+ /* free of (sgl) in fast_flush_area()*/
+ pending_req->sgl = kmalloc_array(nr_segments,
+ sizeof(struct scatterlist), GFP_KERNEL);
+ if (!pending_req->sgl) {
+ pr_err("xen-pvscsi: %s: kmalloc() error\n", __func__);
+ return -ENOMEM;
+ }
+
+ sg_init_table(pending_req->sgl, nr_segments);
+ pending_req->n_sg = nr_segments;
+
+ flags = GNTMAP_host_map;
+ if (pending_req->sc_data_direction == DMA_TO_DEVICE)
+ flags |= GNTMAP_readonly;
+
+ pg = pending_req->pages + nr_sgl;
+ grant = pending_req->grant_handles + nr_sgl;
+ if (!nr_sgl) {
+ seg = ring_req->seg;
+ err = scsiback_gnttab_data_map_list(pending_req, seg,
+ pg, grant, nr_segments, flags);
+ if (err)
+ return err;
+ } else {
+ for (i = 0; i < nr_sgl; i++) {
+ seg = (struct scsiif_request_segment *)(
+ vaddr(pending_req, i) + ring_req->seg[i].offset);
+ n_segs = ring_req->seg[i].length /
+ sizeof(struct scsiif_request_segment);
+ err = scsiback_gnttab_data_map_list(pending_req, seg,
+ pg, grant, n_segs, flags);
+ if (err)
+ return err;
+ pg += n_segs;
+ grant += n_segs;
+ }
+ end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset;
+ seg = (struct scsiif_request_segment *)end_seg;
+ end_seg += ring_req->seg[0].length;
+ pg = pending_req->pages + nr_sgl;
+ }
+
+ for_each_sg(pending_req->sgl, sg, nr_segments, i) {
+ sg_set_page(sg, pg[i], seg->length, seg->offset);
+ pending_req->data_len += seg->length;
+ seg++;
+ if (nr_sgl && (unsigned long)seg >= end_seg) {
+ i_seg++;
+ end_seg = vaddr(pending_req, i_seg) +
+ ring_req->seg[i_seg].offset;
+ seg = (struct scsiif_request_segment *)end_seg;
+ end_seg += ring_req->seg[i_seg].length;
+ }
+ if (sg->offset >= PAGE_SIZE ||
+ sg->length > PAGE_SIZE ||
+ sg->offset + sg->length > PAGE_SIZE)
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void scsiback_notify_work(struct vscsibk_info *info)
+{
+ info->waiting_reqs = 1;
+ wake_up(&info->wq);
+}
+
+static irqreturn_t scsiback_intr(int irq, void *dev_id)
+{
+ scsiback_notify_work((struct vscsibk_info *)dev_id);
+ return IRQ_HANDLED;
+}
+
+static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
+ evtchn_port_t evtchn)
+{
+ void *area;
+ struct vscsiif_sring *sring;
+ int err;
+
+ if (info->irq) {
+ pr_err("xen-pvscsi: Already connected through?\n");
+ return -1;
+ }
+
+ err = xenbus_map_ring_valloc(info->dev, ring_ref, &area);
+ if (err)
+ return err;
+
+ sring = (struct vscsiif_sring *)area;
+ BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
+
+ err = bind_interdomain_evtchn_to_irqhandler(
+ info->domid, evtchn,
+ scsiback_intr, 0, "vscsiif-backend", info);
+
+ if (err < 0)
+ goto unmap_page;
+
+ info->irq = err;
+
+ return 0;
+
+unmap_page:
+ xenbus_unmap_ring_vfree(info->dev, area);
+
+ return err;
+}
+
+static void scsiback_disconnect(struct vscsibk_info *info)
+{
+ if (info->kthread) {
+ kthread_stop(info->kthread);
+ info->kthread = NULL;
+ wake_up(&info->shutdown_wq);
+ }
+
+ wait_event(info->waiting_to_free,
+ atomic_read(&info->nr_unreplied_reqs) == 0);
+
+ if (info->irq) {
+ unbind_from_irqhandler(info->irq, info);
+ info->irq = 0;
+ }
+
+ if (info->ring.sring) {
+ xenbus_unmap_ring_vfree(info->dev, info->ring.sring);
+ info->ring.sring = NULL;
+ }
+}
+
+static void scsiback_device_action(struct vscsibk_pend *pending_req,
+ enum tcm_tmreq_table act, int tag)
+{
+ int rc, err = FAILED;
+ struct scsiback_tpg *tpg = pending_req->v2p->tpg;
+ struct se_cmd *se_cmd = &pending_req->se_cmd;
+ struct scsiback_tmr *tmr;
+
+ tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL);
+ if (!tmr) {
+ pr_err("xen-pvscsi: %s: kmalloc() error\n", __func__);
+ goto out;
+ }
+ init_waitqueue_head(&tmr->tmr_wait);
+
+ transport_init_se_cmd(se_cmd, tpg->se_tpg.se_tpg_tfo,
+ tpg->tpg_nexus->tvn_se_sess, 0, DMA_NONE, MSG_SIMPLE_TAG,
+ &pending_req->sense_buffer[0]);
+
+ rc = core_tmr_alloc_req(se_cmd, tmr, act, GFP_KERNEL);
+ if (rc < 0)
+ goto out;
+
+ se_cmd->se_tmr_req->ref_task_tag = tag;
+
+ if (transport_lookup_tmr_lun(se_cmd, pending_req->v2p->lun) < 0)
+ goto out;
+
+ transport_generic_handle_tmr(se_cmd);
+ wait_event(tmr->tmr_wait, atomic_read(&tmr->tmr_complete));
+
+ err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
+ SUCCESS : FAILED;
+
+out:
+ if (tmr) {
+ transport_generic_free_cmd(&pending_req->se_cmd, 1);
+ kfree(tmr);
+ }
+
+ scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
+}
+
+/*
+ Perform virtual to physical translation
+*/
+static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info,
+ struct ids_tuple *v)
+{
+ struct v2p_entry *entry;
+ struct list_head *head = &(info->v2p_entry_lists);
+ unsigned long flags;
+
+ spin_lock_irqsave(&info->v2p_lock, flags);
+ list_for_each_entry(entry, head, l) {
+ if ((entry->v.chn == v->chn) &&
+ (entry->v.tgt == v->tgt) &&
+ (entry->v.lun == v->lun)) {
+ kref_get(&entry->kref);
+ goto out;
+ }
+ }
+ entry = NULL;
+
+out:
+ spin_unlock_irqrestore(&info->v2p_lock, flags);
+ return entry;
+}
+
+static int prepare_pending_reqs(struct vscsibk_info *info,
+ struct vscsiif_request *ring_req,
+ struct vscsibk_pend *pending_req)
+{
+ struct v2p_entry *v2p;
+ struct ids_tuple vir;
+
+ pending_req->rqid = ring_req->rqid;
+ pending_req->info = info;
+
+ vir.chn = ring_req->channel;
+ vir.tgt = ring_req->id;
+ vir.lun = ring_req->lun;
+
+ v2p = scsiback_do_translation(info, &vir);
+ if (!v2p) {
+ pending_req->v2p = NULL;
+ DPRINTK("xen-pvscsi: doesn't exist.\n");
+ return -ENODEV;
+ }
+ pending_req->v2p = v2p;
+
+ /* request range check from frontend */
+ pending_req->sc_data_direction = ring_req->sc_data_direction;
+ if ((pending_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
+ (pending_req->sc_data_direction != DMA_TO_DEVICE) &&
+ (pending_req->sc_data_direction != DMA_FROM_DEVICE) &&
+ (pending_req->sc_data_direction != DMA_NONE)) {
+ DPRINTK("xen-pvscsi: invalid parameter data_dir = %d\n",
+ pending_req->sc_data_direction);
+ return -EINVAL;
+ }
+
+ pending_req->cmd_len = ring_req->cmd_len;
+ if (pending_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
+ DPRINTK("xen-pvscsi: invalid parameter cmd_len = %d\n",
+ pending_req->cmd_len);
+ return -EINVAL;
+ }
+ memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
+
+ return 0;
+}
+
+static int _scsiback_do_cmd_fn(struct vscsibk_info *info)
+{
+ struct vscsiif_back_ring *ring = &info->ring;
+ struct vscsiif_request *ring_req;
+ struct vscsibk_pend *pending_req;
+ RING_IDX rc, rp;
+ int err, more_to_do = 0;
+ uint32_t result;
+ uint8_t act;
+
+ rc = ring->req_cons;
+ rp = ring->sring->req_prod;
+ rmb(); /* guest system is accessing ring, too */
+
+ if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) {
+ rc = ring->rsp_prod_pvt;
+ pr_warn("xen-pvscsi: Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
+ info->domid, rp, rc, rp - rc);
+ return -EACCES;
+ }
+
+ while ((rc != rp)) {
+ if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
+ break;
+ pending_req = kmem_cache_alloc(scsiback_cachep, GFP_KERNEL);
+ if (NULL == pending_req) {
+ more_to_do = 1;
+ break;
+ }
+
+ ring_req = RING_GET_REQUEST(ring, rc);
+ ring->req_cons = ++rc;
+
+ act = ring_req->act;
+ err = prepare_pending_reqs(info, ring_req, pending_req);
+ if (err) {
+ switch (err) {
+ case -ENODEV:
+ result = DID_NO_CONNECT;
+ break;
+ default:
+ result = DRIVER_ERROR;
+ break;
+ }
+ scsiback_do_resp_with_sense(NULL, result << 24, 0,
+ pending_req);
+ more_to_do = 1;
+ break;
+ }
+
+ switch (act) {
+ case VSCSIIF_ACT_SCSI_CDB:
+ if (scsiback_gnttab_data_map(ring_req, pending_req)) {
+ scsiback_fast_flush_area(pending_req);
+ scsiback_do_resp_with_sense(NULL,
+ DRIVER_ERROR << 24, 0, pending_req);
+ } else {
+ scsiback_cmd_exec(pending_req);
+ }
+ break;
+ case VSCSIIF_ACT_SCSI_ABORT:
+ scsiback_device_action(pending_req, TMR_ABORT_TASK,
+ ring_req->ref_rqid);
+ break;
+ case VSCSIIF_ACT_SCSI_RESET:
+ scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
+ break;
+ default:
+ pr_err_ratelimited("xen-pvscsi: invalid request\n");
+ scsiback_do_resp_with_sense(NULL, DRIVER_ERROR << 24,
+ 0, pending_req);
+ break;
+ }
+
+ /* Yield point for this unbounded loop. */
+ cond_resched();
+ }
+
+ if (RING_HAS_UNCONSUMED_REQUESTS(ring))
+ more_to_do = 1;
+
+ return more_to_do;
+}
+
+static int scsiback_do_cmd_fn(struct vscsibk_info *info)
+{
+ int more_to_do;
+
+ do {
+ more_to_do = _scsiback_do_cmd_fn(info);
+ if (more_to_do)
+ break;
+
+ RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do);
+ } while (more_to_do);
+
+ return more_to_do;
+}
+
+static int scsiback_schedule(void *data)
+{
+ struct vscsibk_info *info = (struct vscsibk_info *)data;
+
+ while (!kthread_should_stop()) {
+ wait_event_interruptible(info->wq,
+ info->waiting_reqs || kthread_should_stop());
+
+ info->waiting_reqs = 0;
+ smp_mb(); /* waiting_reqs used by other thread */
+
+ switch (scsiback_do_cmd_fn(info)) {
+ case 1:
+ info->waiting_reqs = 1;
+ case 0:
+ break;
+ case -EACCES:
+ wait_event_interruptible(info->shutdown_wq,
+ kthread_should_stop());
+ break;
+ default:
+ BUG();
+ }
+ }
+
+ return 0;
+}
+
+static void __vscsiif_name(struct vscsibk_info *info, char *buf)
+{
+ struct xenbus_device *dev = info->dev;
+ unsigned int domid, id;
+
+ if (sscanf(dev->nodename, "backend/vscsi/%u/%u", &domid, &id) == 2)
+ snprintf(buf, TASK_COMM_LEN, "vscsi.%u.%u", info->domid, id);
+ else
+ snprintf(buf, TASK_COMM_LEN, "vscsi.%u..", info->domid);
+}
+
+static int scsiback_map(struct vscsibk_info *info)
+{
+ struct xenbus_device *dev = info->dev;
+ unsigned int ring_ref, evtchn;
+ int err;
+ char name[TASK_COMM_LEN];
+
+ err = xenbus_gather(XBT_NIL, dev->otherend,
+ "ring-ref", "%u", &ring_ref,
+ "event-channel", "%u", &evtchn, NULL);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend);
+ return err;
+ }
+
+ err = scsiback_init_sring(info, ring_ref, evtchn);
+ if (err)
+ return err;
+
+ __vscsiif_name(info, name);
+
+ info->kthread = kthread_run(scsiback_schedule, info, name);
+ if (IS_ERR(info->kthread)) {
+ err = PTR_ERR(info->kthread);
+ info->kthread = NULL;
+ xenbus_dev_error(info->dev, err, "start vscsiif");
+ return err;
+ }
+
+ return 0;
+}
+
+/*
+ Add a new translation entry
+*/
+static int scsiback_add_translation_entry(struct vscsibk_info *info,
+ char *phy, struct ids_tuple *v)
+{
+ int err = 0;
+ struct v2p_entry *entry;
+ struct v2p_entry *new;
+ struct list_head *head = &(info->v2p_entry_lists);
+ unsigned long flags;
+ char *lunp;
+ unsigned int lun;
+ struct scsiback_tpg *tpg_entry, *tpg = NULL;
+ char *error = "doesn't exist";
+
+ lunp = strrchr(phy, ':');
+ if (!lunp) {
+ pr_err("xen-pvscsi: illegal format of physical device %s\n",
+ phy);
+ return -EINVAL;
+ }
+ *lunp = 0;
+ lunp++;
+ if (kstrtouint(lunp, 10, &lun) || lun >= TRANSPORT_MAX_LUNS_PER_TPG) {
+ pr_err("xen-pvscsi: lun number not valid: %s\n", lunp);
+ return -EINVAL;
+ }
+
+ mutex_lock(&scsiback_mutex);
+ list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) {
+ if (!strcmp(phy, tpg_entry->tport->tport_name) ||
+ !strcmp(phy, tpg_entry->param_alias)) {
+ spin_lock(&tpg_entry->se_tpg.tpg_lun_lock);
+ if (tpg_entry->se_tpg.tpg_lun_list[lun]->lun_status ==
+ TRANSPORT_LUN_STATUS_ACTIVE) {
+ if (!tpg_entry->tpg_nexus)
+ error = "nexus undefined";
+ else
+ tpg = tpg_entry;
+ }
+ spin_unlock(&tpg_entry->se_tpg.tpg_lun_lock);
+ break;
+ }
+ }
+ if (tpg) {
+ mutex_lock(&tpg->tv_tpg_mutex);
+ tpg->tv_tpg_fe_count++;
+ mutex_unlock(&tpg->tv_tpg_mutex);
+ }
+ mutex_unlock(&scsiback_mutex);
+
+ if (!tpg) {
+ pr_err("xen-pvscsi: %s:%d %s\n", phy, lun, error);
+ return -ENODEV;
+ }
+
+ new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL);
+ if (new == NULL) {
+ pr_err("xen-pvscsi: %s: kmalloc() error\n", __func__);
+ err = -ENOMEM;
+ goto out_free;
+ }
+
+ spin_lock_irqsave(&info->v2p_lock, flags);
+
+ /* Check double assignment to identical virtual ID */
+ list_for_each_entry(entry, head, l) {
+ if ((entry->v.chn == v->chn) &&
+ (entry->v.tgt == v->tgt) &&
+ (entry->v.lun == v->lun)) {
+ pr_warn("xen-pvscsi: Virtual ID is already used. Assignment was not performed.\n");
+ err = -EEXIST;
+ goto out;
+ }
+
+ }
+
+ /* Create a new translation entry and add to the list */
+ kref_init(&new->kref);
+ new->v = *v;
+ new->tpg = tpg;
+ new->lun = lun;
+ list_add_tail(&new->l, head);
+
+out:
+ spin_unlock_irqrestore(&info->v2p_lock, flags);
+
+out_free:
+ mutex_lock(&tpg->tv_tpg_mutex);
+ tpg->tv_tpg_fe_count--;
+ mutex_unlock(&tpg->tv_tpg_mutex);
+
+ if (err)
+ kfree(new);
+
+ return err;
+}
+
+static void __scsiback_del_translation_entry(struct v2p_entry *entry)
+{
+ list_del(&entry->l);
+ kref_put(&entry->kref, scsiback_free_translation_entry);
+ kfree(entry);
+}
+
+/*
+ Delete the translation entry specfied
+*/
+static int scsiback_del_translation_entry(struct vscsibk_info *info,
+ struct ids_tuple *v)
+{
+ struct v2p_entry *entry;
+ struct list_head *head = &(info->v2p_entry_lists);
+ unsigned long flags;
+
+ spin_lock_irqsave(&info->v2p_lock, flags);
+ /* Find out the translation entry specified */
+ list_for_each_entry(entry, head, l) {
+ if ((entry->v.chn == v->chn) &&
+ (entry->v.tgt == v->tgt) &&
+ (entry->v.lun == v->lun)) {
+ goto found;
+ }
+ }
+
+ spin_unlock_irqrestore(&info->v2p_lock, flags);
+ return 1;
+
+found:
+ /* Delete the translation entry specfied */
+ __scsiback_del_translation_entry(entry);
+
+ spin_unlock_irqrestore(&info->v2p_lock, flags);
+ return 0;
+}
+
+static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
+ char *phy, struct ids_tuple *vir)
+{
+ if (!scsiback_add_translation_entry(info, phy, vir)) {
+ if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
+ "%d", XenbusStateInitialised)) {
+ pr_err("xen-pvscsi: xenbus_printf error %s\n", state);
+ scsiback_del_translation_entry(info, vir);
+ }
+ } else {
+ xenbus_printf(XBT_NIL, info->dev->nodename, state,
+ "%d", XenbusStateClosed);
+ }
+}
+
+static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state,
+ struct ids_tuple *vir)
+{
+ if (!scsiback_del_translation_entry(info, vir)) {
+ if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
+ "%d", XenbusStateClosed))
+ pr_err("xen-pvscsi: xenbus_printf error %s\n", state);
+ }
+}
+
+#define VSCSIBACK_OP_ADD_OR_DEL_LUN 1
+#define VSCSIBACK_OP_UPDATEDEV_STATE 2
+
+static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
+ char *ent)
+{
+ int err;
+ struct ids_tuple vir;
+ char *val;
+ int device_state;
+ char phy[VSCSI_NAMELEN];
+ char str[64];
+ char state[64];
+ struct xenbus_device *dev = info->dev;
+
+ /* read status */
+ snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
+ err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
+ if (XENBUS_EXIST_ERR(err))
+ return;
+
+ /* physical SCSI device */
+ snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
+ val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
+ if (IS_ERR(val)) {
+ xenbus_printf(XBT_NIL, dev->nodename, state,
+ "%d", XenbusStateClosed);
+ return;
+ }
+ strlcpy(phy, val, VSCSI_NAMELEN);
+ kfree(val);
+
+ /* virtual SCSI device */
+ snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
+ err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
+ &vir.hst, &vir.chn, &vir.tgt, &vir.lun);
+ if (XENBUS_EXIST_ERR(err)) {
+ xenbus_printf(XBT_NIL, dev->nodename, state,
+ "%d", XenbusStateClosed);
+ return;
+ }
+
+ switch (op) {
+ case VSCSIBACK_OP_ADD_OR_DEL_LUN:
+ if (device_state == XenbusStateInitialising)
+ scsiback_do_add_lun(info, state, phy, &vir);
+ if (device_state == XenbusStateClosing)
+ scsiback_do_del_lun(info, state, &vir);
+ break;
+
+ case VSCSIBACK_OP_UPDATEDEV_STATE:
+ if (device_state == XenbusStateInitialised) {
+ /* modify vscsi-devs/dev-x/state */
+ if (xenbus_printf(XBT_NIL, dev->nodename, state,
+ "%d", XenbusStateConnected)) {
+ pr_err("xen-pvscsi: xenbus_printf error %s\n",
+ str);
+ scsiback_del_translation_entry(info, &vir);
+ xenbus_printf(XBT_NIL, dev->nodename, state,
+ "%d", XenbusStateClosed);
+ }
+ }
+ break;
+ /*When it is necessary, processing is added here.*/
+ default:
+ break;
+ }
+}
+
+static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op)
+{
+ int i;
+ char **dir;
+ unsigned int ndir = 0;
+
+ dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs",
+ &ndir);
+ if (IS_ERR(dir))
+ return;
+
+ for (i = 0; i < ndir; i++)
+ scsiback_do_1lun_hotplug(info, op, dir[i]);
+
+ kfree(dir);
+}
+
+static void scsiback_frontend_changed(struct xenbus_device *dev,
+ enum xenbus_state frontend_state)
+{
+ struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
+ int err;
+
+ switch (frontend_state) {
+ case XenbusStateInitialising:
+ break;
+ case XenbusStateInitialised:
+ err = scsiback_map(info);
+ if (err)
+ break;
+
+ scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
+ xenbus_switch_state(dev, XenbusStateConnected);
+
+ break;
+ case XenbusStateConnected:
+
+ scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE);
+
+ if (dev->state == XenbusStateConnected)
+ break;
+
+ xenbus_switch_state(dev, XenbusStateConnected);
+
+ break;
+
+ case XenbusStateClosing:
+ scsiback_disconnect(info);
+ xenbus_switch_state(dev, XenbusStateClosing);
+ break;
+
+ case XenbusStateClosed:
+ xenbus_switch_state(dev, XenbusStateClosed);
+ if (xenbus_dev_is_online(dev))
+ break;
+ /* fall through if not online */
+ case XenbusStateUnknown:
+ device_unregister(&dev->dev);
+ break;
+
+ case XenbusStateReconfiguring:
+ scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
+
+ xenbus_switch_state(dev, XenbusStateReconfigured);
+
+ break;
+
+ default:
+ xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
+ frontend_state);
+ break;
+ }
+}
+
+/*
+ Release the translation entry specfied
+*/
+static void scsiback_release_translation_entry(struct vscsibk_info *info)
+{
+ struct v2p_entry *entry, *tmp;
+ struct list_head *head = &(info->v2p_entry_lists);
+ unsigned long flags;
+
+ spin_lock_irqsave(&info->v2p_lock, flags);
+
+ list_for_each_entry_safe(entry, tmp, head, l)
+ __scsiback_del_translation_entry(entry);
+
+ spin_unlock_irqrestore(&info->v2p_lock, flags);
+}
+
+static int scsiback_remove(struct xenbus_device *dev)
+{
+ struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
+
+ scsiback_disconnect(info);
+ scsiback_release_translation_entry(info);
+
+ dev_set_drvdata(&dev->dev, NULL);
+
+ return 0;
+}
+
+static int scsiback_probe(struct xenbus_device *dev,
+ const struct xenbus_device_id *id)
+{
+ int err;
+
+ struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info),
+ GFP_KERNEL);
+
+ DPRINTK("%p %d\n", dev, dev->otherend_id);
+
+ if (!info) {
+ xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure");
+ return -ENOMEM;
+ }
+ info->dev = dev;
+ dev_set_drvdata(&dev->dev, info);
+
+ info->domid = dev->otherend_id;
+ spin_lock_init(&info->ring_lock);
+ atomic_set(&info->nr_unreplied_reqs, 0);
+ init_waitqueue_head(&info->wq);
+ init_waitqueue_head(&info->shutdown_wq);
+ init_waitqueue_head(&info->waiting_to_free);
+ info->dev = dev;
+ info->irq = 0;
+ INIT_LIST_HEAD(&info->v2p_entry_lists);
+ spin_lock_init(&info->v2p_lock);
+
+ err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u",
+ SG_ALL);
+ if (err)
+ xenbus_dev_error(dev, err, "writing feature-sg-grant");
+
+ err = xenbus_switch_state(dev, XenbusStateInitWait);
+ if (err)
+ goto fail;
+
+ return 0;
+
+fail:
+ pr_warn("xen-pvscsi: %s failed\n", __func__);
+ scsiback_remove(dev);
+
+ return err;
+}
+
+static char *scsiback_dump_proto_id(struct scsiback_tport *tport)
+{
+ switch (tport->tport_proto_id) {
+ case SCSI_PROTOCOL_SAS:
+ return "SAS";
+ case SCSI_PROTOCOL_FCP:
+ return "FCP";
+ case SCSI_PROTOCOL_ISCSI:
+ return "iSCSI";
+ default:
+ break;
+ }
+
+ return "Unknown";
+}
+
+static u8 scsiback_get_fabric_proto_ident(struct se_portal_group *se_tpg)
+{
+ struct scsiback_tpg *tpg = container_of(se_tpg,
+ struct scsiback_tpg, se_tpg);
+ struct scsiback_tport *tport = tpg->tport;
+
+ switch (tport->tport_proto_id) {
+ case SCSI_PROTOCOL_SAS:
+ return sas_get_fabric_proto_ident(se_tpg);
+ case SCSI_PROTOCOL_FCP:
+ return fc_get_fabric_proto_ident(se_tpg);
+ case SCSI_PROTOCOL_ISCSI:
+ return iscsi_get_fabric_proto_ident(se_tpg);
+ default:
+ pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
+ tport->tport_proto_id);
+ break;
+ }
+
+ return sas_get_fabric_proto_ident(se_tpg);
+}
+
+static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg)
+{
+ struct scsiback_tpg *tpg = container_of(se_tpg,
+ struct scsiback_tpg, se_tpg);
+ struct scsiback_tport *tport = tpg->tport;
+
+ return &tport->tport_name[0];
+}
+
+static u16 scsiback_get_tag(struct se_portal_group *se_tpg)
+{
+ struct scsiback_tpg *tpg = container_of(se_tpg,
+ struct scsiback_tpg, se_tpg);
+ return tpg->tport_tpgt;
+}
+
+static u32 scsiback_get_default_depth(struct se_portal_group *se_tpg)
+{
+ return 1;
+}
+
+static u32
+scsiback_get_pr_transport_id(struct se_portal_group *se_tpg,
+ struct se_node_acl *se_nacl,
+ struct t10_pr_registration *pr_reg,
+ int *format_code,
+ unsigned char *buf)
+{
+ struct scsiback_tpg *tpg = container_of(se_tpg,
+ struct scsiback_tpg, se_tpg);
+ struct scsiback_tport *tport = tpg->tport;
+
+ switch (tport->tport_proto_id) {
+ case SCSI_PROTOCOL_SAS:
+ return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
+ format_code, buf);
+ case SCSI_PROTOCOL_FCP:
+ return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
+ format_code, buf);
+ case SCSI_PROTOCOL_ISCSI:
+ return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
+ format_code, buf);
+ default:
+ pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
+ tport->tport_proto_id);
+ break;
+ }
+
+ return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
+ format_code, buf);
+}
+
+static u32
+scsiback_get_pr_transport_id_len(struct se_portal_group *se_tpg,
+ struct se_node_acl *se_nacl,
+ struct t10_pr_registration *pr_reg,
+ int *format_code)
+{
+ struct scsiback_tpg *tpg = container_of(se_tpg,
+ struct scsiback_tpg, se_tpg);
+ struct scsiback_tport *tport = tpg->tport;
+
+ switch (tport->tport_proto_id) {
+ case SCSI_PROTOCOL_SAS:
+ return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
+ format_code);
+ case SCSI_PROTOCOL_FCP:
+ return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
+ format_code);
+ case SCSI_PROTOCOL_ISCSI:
+ return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
+ format_code);
+ default:
+ pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
+ tport->tport_proto_id);
+ break;
+ }
+
+ return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
+ format_code);
+}
+
+static char *
+scsiback_parse_pr_out_transport_id(struct se_portal_group *se_tpg,
+ const char *buf,
+ u32 *out_tid_len,
+ char **port_nexus_ptr)
+{
+ struct scsiback_tpg *tpg = container_of(se_tpg,
+ struct scsiback_tpg, se_tpg);
+ struct scsiback_tport *tport = tpg->tport;
+
+ switch (tport->tport_proto_id) {
+ case SCSI_PROTOCOL_SAS:
+ return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
+ port_nexus_ptr);
+ case SCSI_PROTOCOL_FCP:
+ return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
+ port_nexus_ptr);
+ case SCSI_PROTOCOL_ISCSI:
+ return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
+ port_nexus_ptr);
+ default:
+ pr_err("Unknown tport_proto_id: 0x%02x, using SAS emulation\n",
+ tport->tport_proto_id);
+ break;
+ }
+
+ return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
+ port_nexus_ptr);
+}
+
+static struct se_wwn *
+scsiback_make_tport(struct target_fabric_configfs *tf,
+ struct config_group *group,
+ const char *name)
+{
+ struct scsiback_tport *tport;
+ char *ptr;
+ u64 wwpn = 0;
+ int off = 0;
+
+ tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL);
+ if (!tport) {
+ pr_err("Unable to allocate struct scsiback_tport");
+ return ERR_PTR(-ENOMEM);
+ }
+ tport->tport_wwpn = wwpn;
+ /*
+ * Determine the emulated Protocol Identifier and Target Port Name
+ * based on the incoming configfs directory name.
+ */
+ ptr = strstr(name, "naa.");
+ if (ptr) {
+ tport->tport_proto_id = SCSI_PROTOCOL_SAS;
+ goto check_len;
+ }
+ ptr = strstr(name, "fc.");
+ if (ptr) {
+ tport->tport_proto_id = SCSI_PROTOCOL_FCP;
+ off = 3; /* Skip over "fc." */
+ goto check_len;
+ }
+ ptr = strstr(name, "iqn.");
+ if (ptr) {
+ tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
+ goto check_len;
+ }
+
+ pr_err("Unable to locate prefix for emulated Target Port: %s\n", name);
+ kfree(tport);
+ return ERR_PTR(-EINVAL);
+
+check_len:
+ if (strlen(name) >= VSCSI_NAMELEN) {
+ pr_err("Emulated %s Address: %s, exceeds max: %d\n", name,
+ scsiback_dump_proto_id(tport), VSCSI_NAMELEN);
+ kfree(tport);
+ return ERR_PTR(-EINVAL);
+ }
+ snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]);
+
+ pr_debug("xen-pvscsi: Allocated emulated Target %s Address: %s\n",
+ scsiback_dump_proto_id(tport), name);
+
+ return &tport->tport_wwn;
+}
+
+static void scsiback_drop_tport(struct se_wwn *wwn)
+{
+ struct scsiback_tport *tport = container_of(wwn,
+ struct scsiback_tport, tport_wwn);
+
+ pr_debug("xen-pvscsi: Deallocating emulated Target %s Address: %s\n",
+ scsiback_dump_proto_id(tport), tport->tport_name);
+
+ kfree(tport);
+}
+
+static struct se_node_acl *
+scsiback_alloc_fabric_acl(struct se_portal_group *se_tpg)
+{
+ struct scsiback_nacl *nacl;
+
+ nacl = kzalloc(sizeof(struct scsiback_nacl), GFP_KERNEL);
+ if (!nacl) {
+ pr_err("Unable to allocate struct scsiback_nacl\n");
+ return NULL;
+ }
+
+ return &nacl->se_node_acl;
+}
+
+static void
+scsiback_release_fabric_acl(struct se_portal_group *se_tpg,
+ struct se_node_acl *se_nacl)
+{
+ struct scsiback_nacl *nacl = container_of(se_nacl,
+ struct scsiback_nacl, se_node_acl);
+ kfree(nacl);
+}
+
+static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg)
+{
+ return 1;
+}
+
+static struct se_node_acl *
+scsiback_make_nodeacl(struct se_portal_group *se_tpg,
+ struct config_group *group,
+ const char *name)
+{
+ struct se_node_acl *se_nacl, *se_nacl_new;
+ struct scsiback_nacl *nacl;
+ u64 wwpn = 0;
+ u32 nexus_depth;
+
+ se_nacl_new = scsiback_alloc_fabric_acl(se_tpg);
+ if (!se_nacl_new)
+ return ERR_PTR(-ENOMEM);
+
+ nexus_depth = 1;
+ /*
+ * se_nacl_new may be released by core_tpg_add_initiator_node_acl()
+ * when converting a NodeACL from demo mode -> explict
+ */
+ se_nacl = core_tpg_add_initiator_node_acl(se_tpg, se_nacl_new,
+ name, nexus_depth);
+ if (IS_ERR(se_nacl)) {
+ scsiback_release_fabric_acl(se_tpg, se_nacl_new);
+ return se_nacl;
+ }
+ /*
+ * Locate our struct scsiback_nacl and set the FC Nport WWPN
+ */
+ nacl = container_of(se_nacl, struct scsiback_nacl, se_node_acl);
+ nacl->iport_wwpn = wwpn;
+
+ return se_nacl;
+}
+
+static void scsiback_drop_nodeacl(struct se_node_acl *se_acl)
+{
+ struct scsiback_nacl *nacl = container_of(se_acl,
+ struct scsiback_nacl, se_node_acl);
+ core_tpg_del_initiator_node_acl(se_acl->se_tpg, se_acl, 1);
+ kfree(nacl);
+}
+
+static int scsiback_check_stop_free(struct se_cmd *se_cmd)
+{
+ return target_put_sess_cmd(se_cmd->se_sess, se_cmd);
+}
+
+static void scsiback_release_cmd(struct se_cmd *se_cmd)
+{
+}
+
+static int scsiback_shutdown_session(struct se_session *se_sess)
+{
+ return 0;
+}
+
+static void scsiback_close_session(struct se_session *se_sess)
+{
+}
+
+static u32 scsiback_sess_get_index(struct se_session *se_sess)
+{
+ return 0;
+}
+
+static int scsiback_write_pending(struct se_cmd *se_cmd)
+{
+ /* Go ahead and process the write immediately */
+ target_execute_cmd(se_cmd);
+
+ return 0;
+}
+
+static int scsiback_write_pending_status(struct se_cmd *se_cmd)
+{
+ return 0;
+}
+
+static void scsiback_set_default_node_attrs(struct se_node_acl *nacl)
+{
+}
+
+static u32 scsiback_get_task_tag(struct se_cmd *se_cmd)
+{
+ struct vscsibk_pend *pending_req = container_of(se_cmd,
+ struct vscsibk_pend, se_cmd);
+
+ return pending_req->rqid;
+}
+
+static int scsiback_get_cmd_state(struct se_cmd *se_cmd)
+{
+ return 0;
+}
+
+static int scsiback_queue_data_in(struct se_cmd *se_cmd)
+{
+ struct vscsibk_pend *pending_req = container_of(se_cmd,
+ struct vscsibk_pend, se_cmd);
+
+ pending_req->result = SAM_STAT_GOOD;
+ scsiback_cmd_done(pending_req);
+ return 0;
+}
+
+static int scsiback_queue_status(struct se_cmd *se_cmd)
+{
+ struct vscsibk_pend *pending_req = container_of(se_cmd,
+ struct vscsibk_pend, se_cmd);
+
+ if (se_cmd->sense_buffer &&
+ ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
+ (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE)))
+ pending_req->result = (DRIVER_SENSE << 24) |
+ SAM_STAT_CHECK_CONDITION;
+ else
+ pending_req->result = se_cmd->scsi_status;
+
+ scsiback_cmd_done(pending_req);
+ return 0;
+}
+
+static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd)
+{
+ struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
+ struct scsiback_tmr *tmr = se_tmr->fabric_tmr_ptr;
+
+ atomic_set(&tmr->tmr_complete, 1);
+ wake_up(&tmr->tmr_wait);
+}
+
+static void scsiback_aborted_task(struct se_cmd *se_cmd)
+{
+ struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
+ struct scsiback_tmr *tmr = se_tmr->fabric_tmr_ptr;
+
+ atomic_set(&tmr->tmr_complete, 1);
+ wake_up(&tmr->tmr_wait);
+}
+
+static ssize_t scsiback_tpg_param_show_alias(struct se_portal_group *se_tpg,
+ char *page)
+{
+ struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
+ se_tpg);
+ ssize_t rb;
+
+ mutex_lock(&tpg->tv_tpg_mutex);
+ rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias);
+ mutex_unlock(&tpg->tv_tpg_mutex);
+
+ return rb;
+}
+
+static ssize_t scsiback_tpg_param_store_alias(struct se_portal_group *se_tpg,
+ const char *page, size_t count)
+{
+ struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
+ se_tpg);
+ int len;
+
+ if (strlen(page) >= VSCSI_NAMELEN) {
+ pr_err("param alias: %s, exceeds max: %d\n", page,
+ VSCSI_NAMELEN);
+ return -EINVAL;
+ }
+
+ mutex_lock(&tpg->tv_tpg_mutex);
+ len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page);
+ if (tpg->param_alias[len - 1] == '\n')
+ tpg->param_alias[len - 1] = '\0';
+ mutex_unlock(&tpg->tv_tpg_mutex);
+
+ return count;
+}
+
+TF_TPG_PARAM_ATTR(scsiback, alias, S_IRUGO | S_IWUSR);
+
+static struct configfs_attribute *scsiback_param_attrs[] = {
+ &scsiback_tpg_param_alias.attr,
+ NULL,
+};
+
+static int scsiback_make_nexus(struct scsiback_tpg *tpg,
+ const char *name)
+{
+ struct se_portal_group *se_tpg;
+ struct se_session *se_sess;
+ struct scsiback_nexus *tv_nexus;
+
+ mutex_lock(&tpg->tv_tpg_mutex);
+ if (tpg->tpg_nexus) {
+ mutex_unlock(&tpg->tv_tpg_mutex);
+ pr_debug("tpg->tpg_nexus already exists\n");
+ return -EEXIST;
+ }
+ se_tpg = &tpg->se_tpg;
+
+ tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL);
+ if (!tv_nexus) {
+ mutex_unlock(&tpg->tv_tpg_mutex);
+ pr_err("Unable to allocate struct scsiback_nexus\n");
+ return -ENOMEM;
+ }
+ /*
+ * Initialize the struct se_session pointer
+ */
+ tv_nexus->tvn_se_sess = transport_init_session(TARGET_PROT_DIN_PASS |
+ TARGET_PROT_DOUT_PASS);
+ if (IS_ERR(tv_nexus->tvn_se_sess)) {
+ mutex_unlock(&tpg->tv_tpg_mutex);
+ kfree(tv_nexus);
+ return -ENOMEM;
+ }
+ se_sess = tv_nexus->tvn_se_sess;
+ /*
+ * Since we are running in 'demo mode' this call with generate a
+ * struct se_node_acl for the scsiback struct se_portal_group with
+ * the SCSI Initiator port name of the passed configfs group 'name'.
+ */
+ tv_nexus->tvn_se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
+ se_tpg, (unsigned char *)name);
+ if (!tv_nexus->tvn_se_sess->se_node_acl) {
+ mutex_unlock(&tpg->tv_tpg_mutex);
+ pr_debug("core_tpg_check_initiator_node_acl() failed for %s\n",
+ name);
+ goto out;
+ }
+ /*
+ * Now register the TCM pvscsi virtual I_T Nexus as active with the
+ * call to __transport_register_session()
+ */
+ __transport_register_session(se_tpg, tv_nexus->tvn_se_sess->se_node_acl,
+ tv_nexus->tvn_se_sess, tv_nexus);
+ tpg->tpg_nexus = tv_nexus;
+
+ mutex_unlock(&tpg->tv_tpg_mutex);
+ return 0;
+
+out:
+ transport_free_session(se_sess);
+ kfree(tv_nexus);
+ return -ENOMEM;
+}
+
+static int scsiback_drop_nexus(struct scsiback_tpg *tpg)
+{
+ struct se_session *se_sess;
+ struct scsiback_nexus *tv_nexus;
+
+ mutex_lock(&tpg->tv_tpg_mutex);
+ tv_nexus = tpg->tpg_nexus;
+ if (!tv_nexus) {
+ mutex_unlock(&tpg->tv_tpg_mutex);
+ return -ENODEV;
+ }
+
+ se_sess = tv_nexus->tvn_se_sess;
+ if (!se_sess) {
+ mutex_unlock(&tpg->tv_tpg_mutex);
+ return -ENODEV;
+ }
+
+ if (tpg->tv_tpg_port_count != 0) {
+ mutex_unlock(&tpg->tv_tpg_mutex);
+ pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n",
+ tpg->tv_tpg_port_count);
+ return -EBUSY;
+ }
+
+ if (tpg->tv_tpg_fe_count != 0) {
+ mutex_unlock(&tpg->tv_tpg_mutex);
+ pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n",
+ tpg->tv_tpg_fe_count);
+ return -EBUSY;
+ }
+
+ pr_debug("xen-pvscsi: Removing I_T Nexus to emulated %s Initiator Port: %s\n",
+ scsiback_dump_proto_id(tpg->tport),
+ tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
+
+ /*
+ * Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port
+ */
+ transport_deregister_session(tv_nexus->tvn_se_sess);
+ tpg->tpg_nexus = NULL;
+ mutex_unlock(&tpg->tv_tpg_mutex);
+
+ kfree(tv_nexus);
+ return 0;
+}
+
+static ssize_t scsiback_tpg_show_nexus(struct se_portal_group *se_tpg,
+ char *page)
+{
+ struct scsiback_tpg *tpg = container_of(se_tpg,
+ struct scsiback_tpg, se_tpg);
+ struct scsiback_nexus *tv_nexus;
+ ssize_t ret;
+
+ mutex_lock(&tpg->tv_tpg_mutex);
+ tv_nexus = tpg->tpg_nexus;
+ if (!tv_nexus) {
+ mutex_unlock(&tpg->tv_tpg_mutex);
+ return -ENODEV;
+ }
+ ret = snprintf(page, PAGE_SIZE, "%s\n",
+ tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
+ mutex_unlock(&tpg->tv_tpg_mutex);
+
+ return ret;
+}
+
+static ssize_t scsiback_tpg_store_nexus(struct se_portal_group *se_tpg,
+ const char *page,
+ size_t count)
+{
+ struct scsiback_tpg *tpg = container_of(se_tpg,
+ struct scsiback_tpg, se_tpg);
+ struct scsiback_tport *tport_wwn = tpg->tport;
+ unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr;
+ int ret;
+ /*
+ * Shutdown the active I_T nexus if 'NULL' is passed..
+ */
+ if (!strncmp(page, "NULL", 4)) {
+ ret = scsiback_drop_nexus(tpg);
+ return (!ret) ? count : ret;
+ }
+ /*
+ * Otherwise make sure the passed virtual Initiator port WWN matches
+ * the fabric protocol_id set in scsiback_make_tport(), and call
+ * scsiback_make_nexus().
+ */
+ if (strlen(page) >= VSCSI_NAMELEN) {
+ pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
+ page, VSCSI_NAMELEN);
+ return -EINVAL;
+ }
+ snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page);
+
+ ptr = strstr(i_port, "naa.");
+ if (ptr) {
+ if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
+ pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
+ i_port, scsiback_dump_proto_id(tport_wwn));
+ return -EINVAL;
+ }
+ port_ptr = &i_port[0];
+ goto check_newline;
+ }
+ ptr = strstr(i_port, "fc.");
+ if (ptr) {
+ if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
+ pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
+ i_port, scsiback_dump_proto_id(tport_wwn));
+ return -EINVAL;
+ }
+ port_ptr = &i_port[3]; /* Skip over "fc." */
+ goto check_newline;
+ }
+ ptr = strstr(i_port, "iqn.");
+ if (ptr) {
+ if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
+ pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
+ i_port, scsiback_dump_proto_id(tport_wwn));
+ return -EINVAL;
+ }
+ port_ptr = &i_port[0];
+ goto check_newline;
+ }
+ pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
+ i_port);
+ return -EINVAL;
+ /*
+ * Clear any trailing newline for the NAA WWN
+ */
+check_newline:
+ if (i_port[strlen(i_port) - 1] == '\n')
+ i_port[strlen(i_port) - 1] = '\0';
+
+ ret = scsiback_make_nexus(tpg, port_ptr);
+ if (ret < 0)
+ return ret;
+
+ return count;
+}
+
+TF_TPG_BASE_ATTR(scsiback, nexus, S_IRUGO | S_IWUSR);
+
+static struct configfs_attribute *scsiback_tpg_attrs[] = {
+ &scsiback_tpg_nexus.attr,
+ NULL,
+};
+
+static ssize_t
+scsiback_wwn_show_attr_version(struct target_fabric_configfs *tf,
+ char *page)
+{
+ return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
+ UTS_RELEASE"\n",
+ VSCSI_VERSION, utsname()->sysname, utsname()->machine);
+}
+
+TF_WWN_ATTR_RO(scsiback, version);
+
+static struct configfs_attribute *scsiback_wwn_attrs[] = {
+ &scsiback_wwn_version.attr,
+ NULL,
+};
+
+static char *scsiback_get_fabric_name(void)
+{
+ return "xen-pvscsi";
+}
+
+static int scsiback_port_link(struct se_portal_group *se_tpg,
+ struct se_lun *lun)
+{
+ struct scsiback_tpg *tpg = container_of(se_tpg,
+ struct scsiback_tpg, se_tpg);
+
+ mutex_lock(&scsiback_mutex);
+
+ mutex_lock(&tpg->tv_tpg_mutex);
+ tpg->tv_tpg_port_count++;
+ mutex_unlock(&tpg->tv_tpg_mutex);
+
+ mutex_unlock(&scsiback_mutex);
+
+ return 0;
+}
+
+static void scsiback_port_unlink(struct se_portal_group *se_tpg,
+ struct se_lun *lun)
+{
+ struct scsiback_tpg *tpg = container_of(se_tpg,
+ struct scsiback_tpg, se_tpg);
+
+ mutex_lock(&scsiback_mutex);
+
+ mutex_lock(&tpg->tv_tpg_mutex);
+ tpg->tv_tpg_port_count--;
+ mutex_unlock(&tpg->tv_tpg_mutex);
+
+ mutex_unlock(&scsiback_mutex);
+}
+
+static struct se_portal_group *
+scsiback_make_tpg(struct se_wwn *wwn,
+ struct config_group *group,
+ const char *name)
+{
+ struct scsiback_tport *tport = container_of(wwn,
+ struct scsiback_tport, tport_wwn);
+
+ struct scsiback_tpg *tpg;
+ unsigned long tpgt;
+ int ret;
+
+ if (strstr(name, "tpgt_") != name)
+ return ERR_PTR(-EINVAL);
+ if (kstrtoul(name + 5, 10, &tpgt) || tpgt > UINT_MAX)
+ return ERR_PTR(-EINVAL);
+
+ tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL);
+ if (!tpg) {
+ pr_err("Unable to allocate struct scsiback_tpg");
+ return ERR_PTR(-ENOMEM);
+ }
+ mutex_init(&tpg->tv_tpg_mutex);
+ INIT_LIST_HEAD(&tpg->tv_tpg_list);
+ INIT_LIST_HEAD(&tpg->info_list);
+ tpg->tport = tport;
+ tpg->tport_tpgt = tpgt;
+
+ ret = core_tpg_register(&scsiback_fabric_configfs->tf_ops, wwn,
+ &tpg->se_tpg, tpg, TRANSPORT_TPG_TYPE_NORMAL);
+ if (ret < 0) {
+ kfree(tpg);
+ return NULL;
+ }
+ mutex_lock(&scsiback_mutex);
+ list_add_tail(&tpg->tv_tpg_list, &scsiback_list);
+ mutex_unlock(&scsiback_mutex);
+
+ return &tpg->se_tpg;
+}
+
+static void scsiback_drop_tpg(struct se_portal_group *se_tpg)
+{
+ struct scsiback_tpg *tpg = container_of(se_tpg,
+ struct scsiback_tpg, se_tpg);
+
+ mutex_lock(&scsiback_mutex);
+ list_del(&tpg->tv_tpg_list);
+ mutex_unlock(&scsiback_mutex);
+ /*
+ * Release the virtual I_T Nexus for this xen-pvscsi TPG
+ */
+ scsiback_drop_nexus(tpg);
+ /*
+ * Deregister the se_tpg from TCM..
+ */
+ core_tpg_deregister(se_tpg);
+ kfree(tpg);
+}
+
+static int scsiback_check_true(struct se_portal_group *se_tpg)
+{
+ return 1;
+}
+
+static int scsiback_check_false(struct se_portal_group *se_tpg)
+{
+ return 0;
+}
+
+static struct target_core_fabric_ops scsiback_ops = {
+ .get_fabric_name = scsiback_get_fabric_name,
+ .get_fabric_proto_ident = scsiback_get_fabric_proto_ident,
+ .tpg_get_wwn = scsiback_get_fabric_wwn,
+ .tpg_get_tag = scsiback_get_tag,
+ .tpg_get_default_depth = scsiback_get_default_depth,
+ .tpg_get_pr_transport_id = scsiback_get_pr_transport_id,
+ .tpg_get_pr_transport_id_len = scsiback_get_pr_transport_id_len,
+ .tpg_parse_pr_out_transport_id = scsiback_parse_pr_out_transport_id,
+ .tpg_check_demo_mode = scsiback_check_true,
+ .tpg_check_demo_mode_cache = scsiback_check_true,
+ .tpg_check_demo_mode_write_protect = scsiback_check_false,
+ .tpg_check_prod_mode_write_protect = scsiback_check_false,
+ .tpg_alloc_fabric_acl = scsiback_alloc_fabric_acl,
+ .tpg_release_fabric_acl = scsiback_release_fabric_acl,
+ .tpg_get_inst_index = scsiback_tpg_get_inst_index,
+ .check_stop_free = scsiback_check_stop_free,
+ .release_cmd = scsiback_release_cmd,
+ .put_session = NULL,
+ .shutdown_session = scsiback_shutdown_session,
+ .close_session = scsiback_close_session,
+ .sess_get_index = scsiback_sess_get_index,
+ .sess_get_initiator_sid = NULL,
+ .write_pending = scsiback_write_pending,
+ .write_pending_status = scsiback_write_pending_status,
+ .set_default_node_attributes = scsiback_set_default_node_attrs,
+ .get_task_tag = scsiback_get_task_tag,
+ .get_cmd_state = scsiback_get_cmd_state,
+ .queue_data_in = scsiback_queue_data_in,
+ .queue_status = scsiback_queue_status,
+ .queue_tm_rsp = scsiback_queue_tm_rsp,
+ .aborted_task = scsiback_aborted_task,
+ /*
+ * Setup callers for generic logic in target_core_fabric_configfs.c
+ */
+ .fabric_make_wwn = scsiback_make_tport,
+ .fabric_drop_wwn = scsiback_drop_tport,
+ .fabric_make_tpg = scsiback_make_tpg,
+ .fabric_drop_tpg = scsiback_drop_tpg,
+ .fabric_post_link = scsiback_port_link,
+ .fabric_pre_unlink = scsiback_port_unlink,
+ .fabric_make_np = NULL,
+ .fabric_drop_np = NULL,
+ .fabric_make_nodeacl = scsiback_make_nodeacl,
+ .fabric_drop_nodeacl = scsiback_drop_nodeacl,
+};
+
+static int scsiback_register_configfs(void)
+{
+ struct target_fabric_configfs *fabric;
+ int ret;
+
+ pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
+ VSCSI_VERSION, utsname()->sysname, utsname()->machine);
+ /*
+ * Register the top level struct config_item_type with TCM core
+ */
+ fabric = target_fabric_configfs_init(THIS_MODULE, "xen-pvscsi");
+ if (IS_ERR(fabric)) {
+ pr_err("target_fabric_configfs_init() failed\n");
+ return PTR_ERR(fabric);
+ }
+ /*
+ * Setup fabric->tf_ops from our local scsiback_ops
+ */
+ fabric->tf_ops = scsiback_ops;
+ /*
+ * Setup default attribute lists for various fabric->tf_cit_tmpl
+ */
+ fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = scsiback_wwn_attrs;
+ fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = scsiback_tpg_attrs;
+ fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = NULL;
+ fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = scsiback_param_attrs;
+ fabric->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
+ fabric->tf_cit_tmpl.tfc_tpg_nacl_base_cit.ct_attrs = NULL;
+ fabric->tf_cit_tmpl.tfc_tpg_nacl_attrib_cit.ct_attrs = NULL;
+ fabric->tf_cit_tmpl.tfc_tpg_nacl_auth_cit.ct_attrs = NULL;
+ fabric->tf_cit_tmpl.tfc_tpg_nacl_param_cit.ct_attrs = NULL;
+ /*
+ * Register the fabric for use within TCM
+ */
+ ret = target_fabric_configfs_register(fabric);
+ if (ret < 0) {
+ pr_err("xen-pvscsi: target_fabric_configfs_register() failed\n");
+ return ret;
+ }
+ /*
+ * Setup our local pointer to *fabric
+ */
+ scsiback_fabric_configfs = fabric;
+ pr_debug("xen-pvscsi: Set fabric -> scsiback_fabric_configfs\n");
+ return 0;
+};
+
+static void scsiback_deregister_configfs(void)
+{
+ if (!scsiback_fabric_configfs)
+ return;
+
+ target_fabric_configfs_deregister(scsiback_fabric_configfs);
+ scsiback_fabric_configfs = NULL;
+ pr_debug("xen-pvscsi: Cleared scsiback_fabric_configfs\n");
+};
+
+static const struct xenbus_device_id scsiback_ids[] = {
+ { "vscsi" },
+ { "" }
+};
+
+static DEFINE_XENBUS_DRIVER(scsiback, ,
+ .probe = scsiback_probe,
+ .remove = scsiback_remove,
+ .otherend_changed = scsiback_frontend_changed
+);
+
+static void scsiback_init_pend(void *p)
+{
+ struct vscsibk_pend *pend = p;
+ int i;
+
+ memset(pend, 0, sizeof(*pend));
+ for (i = 0; i < VSCSI_MAX_GRANTS; i++)
+ pend->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
+}
+
+static int __init scsiback_init(void)
+{
+ int ret;
+
+ if (!xen_domain())
+ return -ENODEV;
+
+ scsiback_cachep = kmem_cache_create("vscsiif_cache",
+ sizeof(struct vscsibk_pend), 0, 0, scsiback_init_pend);
+ if (!scsiback_cachep) {
+ pr_err("xen-pvscsi: can't init scsi cache\n");
+ return -ENOMEM;
+ }
+
+ ret = xenbus_register_backend(&scsiback_driver);
+ if (ret)
+ goto out_cache_destroy;
+
+ ret = scsiback_register_configfs();
+ if (ret)
+ goto out_unregister_xenbus;
+
+ return 0;
+
+out_unregister_xenbus:
+ xenbus_unregister_driver(&scsiback_driver);
+out_cache_destroy:
+ kmem_cache_destroy(scsiback_cachep);
+ pr_err("xen-pvscsi: %s: error %d\n", __func__, ret);
+ return ret;
+}
+
+static void __exit scsiback_exit(void)
+{
+ struct page *page;
+
+ while (free_pages_num) {
+ if (get_free_page(&page))
+ BUG();
+ free_xenballooned_pages(1, &page);
+ }
+ scsiback_deregister_configfs();
+ xenbus_unregister_driver(&scsiback_driver);
+ kmem_cache_destroy(scsiback_cachep);
+}
+
+module_init(scsiback_init);
+module_exit(scsiback_exit);
+
+MODULE_DESCRIPTION("Xen SCSI backend driver");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("xen-backend:vscsi");
--
1.8.4.5
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