xen/libxl.pvscsi.patch

Subject: [PATCH v12 1/2] libxl: add support for vscsi
Date: Wed, 13 Apr 2016 08:56:59 +0000
Message-Id: <1460537820-15398-2-git-send-email-olaf@aepfle.de>
fate#316613 , https://fate.suse.com/316613

Port pvscsi support from xend to libxl:

 vscsi=['pdev,vdev{,options}']
 xl scsi-attach
 xl scsi-detach
 xl scsi-list

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
---
 docs/man/xl.cfg.pod.5                |   56 +
 docs/man/xl.pod.1                    |   18 
 tools/libxl/Makefile                 |    2 
 tools/libxl/libxl.c                  |    9 
 tools/libxl/libxl.h                  |   42 +
 tools/libxl/libxl_create.c           |   41 +
 tools/libxl/libxl_device.c           |    2 
 tools/libxl/libxl_internal.h         |    8 
 tools/libxl/libxl_types.idl          |   53 +
 tools/libxl/libxl_types_internal.idl |    1 
 tools/libxl/libxl_vscsi.c            | 1169 +++++++++++++++++++++++++++++++++++
 tools/libxl/libxlu_vscsi.c           |  667 +++++++++++++++++++
 tools/libxl/libxlutil.h              |   19 
 tools/libxl/xl.h                     |    3 
 tools/libxl/xl_cmdimpl.c             |  225 ++++++
 tools/libxl/xl_cmdtable.c            |   15 
 16 files changed, 2326 insertions(+), 4 deletions(-)

Index: xen-4.7.0-testing/docs/man/xl.cfg.pod.5
===================================================================
--- xen-4.7.0-testing.orig/docs/man/xl.cfg.pod.5
+++ xen-4.7.0-testing/docs/man/xl.cfg.pod.5
@@ -517,6 +517,62 @@ value is optional if this is a guest dom
 
 =back
 
+=item B<vscsi=[ "VSCSI_SPEC_STRING", "VSCSI_SPEC_STRING", ...]>
+
+Specifies the PVSCSI devices to be provided to the guest. PVSCSI passes
+SCSI devices from the backend domain to the guest.
+
+Each VSCSI_SPEC_STRING consists of "pdev,vdev[,options]".
+'pdev' describes the physical device, preferable in a persistent format
+such as /dev/disk/by-*/*.
+'vdev' is the domU device in vHOST:CHANNEL:TARGET:LUN notation, all integers.
+'options' lists additional flags which a backend may recognize.
+
+The supported values for "pdev" and "options" depends on the backend driver used:
+
+=over 4
+
+=item B<Linux>
+
+=over 4
+
+=item C<pdev>
+
+The backend driver in the pvops kernel is part of the Linux-IO Target framework
+(LIO). As such the SCSI devices have to be configured first with the tools
+provided by this framework, such as a xen-scsiback aware targetcli. The "pdev"
+in domU.cfg has to refer to a config item in that framework instead of the raw
+device. Usually this is a WWN in the form of "naa.WWN:LUN".
+
+=item C<options>
+
+No options recognized.
+
+=back
+
+=item B<Linux based on classic Xen kernel>
+
+=over 4
+
+=item C<pdev>
+
+The dom0 device in either /dev/scsidev or pHOST:CHANNEL:TARGET:LUN notation.
+
+It's recommended to use persistent names "/dev/disk/by-*/*" to refer to a "pdev".
+The toolstack will translate this internally to "h:c:t:l" notation, which is how
+the backend driver will access the device. Using the "h:c:t:l" notation for
+"pdev" in domU.cfg is discouraged because this value will change across reboots,
+depending on the detection order in the OS.
+
+=item C<options>
+
+Currently only the option value "feature-host" is recognized. SCSI command
+emulation in backend driver is bypassed when "feature-host" is specified.
+
+=back
+
+=back
+
 =item B<vfb=[ "VFB_SPEC_STRING", "VFB_SPEC_STRING", ...]>
 
 Specifies the paravirtual framebuffer devices which should be supplied
Index: xen-4.7.0-testing/docs/man/xl.pod.1
===================================================================
--- xen-4.7.0-testing.orig/docs/man/xl.pod.1
+++ xen-4.7.0-testing/docs/man/xl.pod.1
@@ -1423,6 +1423,24 @@ List virtual trusted platform modules fo
 
 =back
 
+=head2 PVSCSI DEVICES
+
+=over 4
+
+=item B<scsi-attach> I<domain-id> I<pdev> I<vdev>,I<[feature-host]>
+
+Creates a new vscsi device in the domain specified by I<domain-id>.
+
+=item B<scsi-detach> I<domain-id> I<vdev>
+
+Removes the vscsi device from domain specified by I<domain-id>.
+
+=item B<scsi-list> I<domain-id> I<[domain-id] ...>
+
+List vscsi devices for the domain specified by I<domain-id>.
+
+=back
+
 =head1 PCI PASS-THROUGH
 
 =over 4
Index: xen-4.7.0-testing/tools/libxl/Makefile
===================================================================
--- xen-4.7.0-testing.orig/tools/libxl/Makefile
+++ xen-4.7.0-testing/tools/libxl/Makefile
@@ -108,6 +108,7 @@ endif
 LIBXL_LIBS += -lyajl
 
 LIBXL_OBJS = flexarray.o libxl.o libxl_create.o libxl_dm.o libxl_pci.o \
+			libxl_vscsi.o \
 			libxl_dom.o libxl_exec.o libxl_xshelp.o libxl_device.o \
 			libxl_internal.o libxl_utils.o libxl_uuid.o \
 			libxl_json.o libxl_aoutils.o libxl_numa.o libxl_vnuma.o \
@@ -151,6 +152,7 @@ AUTOINCS= libxlu_cfg_y.h libxlu_cfg_l.h
 AUTOSRCS= libxlu_cfg_y.c libxlu_cfg_l.c
 AUTOSRCS += _libxl_save_msgs_callout.c _libxl_save_msgs_helper.c
 LIBXLU_OBJS = libxlu_cfg_y.o libxlu_cfg_l.o libxlu_cfg.o \
+	libxlu_vscsi.o \
 	libxlu_disk_l.o libxlu_disk.o libxlu_vif.o libxlu_pci.o
 $(LIBXLU_OBJS): CFLAGS += $(CFLAGS_libxenctrl) # For xentoollog.h
 
Index: xen-4.7.0-testing/tools/libxl/libxl.c
===================================================================
--- xen-4.7.0-testing.orig/tools/libxl/libxl.c
+++ xen-4.7.0-testing/tools/libxl/libxl.c
@@ -4326,6 +4326,7 @@ DEFINE_DEVICE_REMOVE_CUSTOM(usbctrl, des
 /* The following functions are defined:
  * libxl_device_disk_add
  * libxl_device_nic_add
+ * libxl_device_vscsictrl_add
  * libxl_device_vtpm_add
  * libxl_device_usbctrl_add
  * libxl_device_usbdev_add
@@ -4357,6 +4358,9 @@ DEFINE_DEVICE_ADD(disk)
 /* nic */
 DEFINE_DEVICE_ADD(nic)
 
+/* vscsi */
+DEFINE_DEVICE_ADD(vscsictrl)
+
 /* vtpm */
 DEFINE_DEVICE_ADD(vtpm)
 
@@ -7309,6 +7313,11 @@ int libxl_retrieve_domain_configuration(
 
     MERGE(nic, nics, COMPARE_DEVID, {});
 
+    MERGE(vscsictrl, vscsictrls, COMPARE_DEVID, {
+            libxl_device_vscsictrl_dispose(dst);
+            libxl_device_vscsictrl_copy(CTX, dst, src);
+          });
+
     MERGE(vtpm, vtpms, COMPARE_DEVID, {});
 
     MERGE(pci, pcidevs, COMPARE_PCI, {});
Index: xen-4.7.0-testing/tools/libxl/libxl.h
===================================================================
--- xen-4.7.0-testing.orig/tools/libxl/libxl.h
+++ xen-4.7.0-testing/tools/libxl/libxl.h
@@ -880,6 +880,13 @@ void libxl_mac_copy(libxl_ctx *ctx, libx
 #define LIBXL_HAVE_PCITOPOLOGY 1
 
 /*
+ * LIBXL_HAVE_VSCSI
+ *
+ * If this is defined, the PV SCSI feature is supported.
+ */
+#define LIBXL_HAVE_VSCSI 1
+
+/*
  * LIBXL_HAVE_SOCKET_BITMAP
  *
  * If this is defined, then libxl_socket_bitmap_alloc and
@@ -1710,6 +1717,41 @@ int libxl_device_channel_getinfo(libxl_c
                                  libxl_device_channel *channel,
                                  libxl_channelinfo *channelinfo);
 
+/* Virtual SCSI */
+int libxl_device_vscsictrl_add(libxl_ctx *ctx, uint32_t domid,
+                               libxl_device_vscsictrl *vscsi,
+                               const libxl_asyncop_how *ao_how)
+                               LIBXL_EXTERNAL_CALLERS_ONLY;
+int libxl_device_vscsictrl_remove(libxl_ctx *ctx, uint32_t domid,
+                                  libxl_device_vscsictrl *vscsi,
+                                  const libxl_asyncop_how *ao_how)
+                                  LIBXL_EXTERNAL_CALLERS_ONLY;
+int libxl_device_vscsictrl_destroy(libxl_ctx *ctx, uint32_t domid,
+                                   libxl_device_vscsictrl *vscsi,
+                                   const libxl_asyncop_how *ao_how)
+                                   LIBXL_EXTERNAL_CALLERS_ONLY;
+
+libxl_device_vscsictrl *libxl_device_vscsictrl_list(libxl_ctx *ctx, uint32_t domid, int *num);
+int libxl_device_vscsictrl_getinfo(libxl_ctx *ctx, uint32_t domid,
+                                   libxl_device_vscsictrl *vscsictrl,
+                                   libxl_device_vscsidev *vscsidev,
+                                   libxl_vscsiinfo *vscsiinfo);
+int libxl_device_vscsidev_add(libxl_ctx *ctx, uint32_t domid,
+                              libxl_device_vscsidev *dev,
+                              const libxl_asyncop_how *ao_how)
+                              LIBXL_EXTERNAL_CALLERS_ONLY;
+/* Remove vscsidev connected to vscsictrl */
+int libxl_device_vscsidev_remove(libxl_ctx *ctx, uint32_t domid,
+                                 libxl_device_vscsidev *dev,
+                                 const libxl_asyncop_how *ao_how)
+                                 LIBXL_EXTERNAL_CALLERS_ONLY;
+void libxl_device_vscsictrl_append_vscsidev(libxl_ctx *ctx,
+                                            libxl_device_vscsictrl *ctrl,
+                                            libxl_device_vscsidev *dev);
+void libxl_device_vscsictrl_remove_vscsidev(libxl_ctx *ctx,
+                                            libxl_device_vscsictrl *ctrl,
+                                            unsigned int idx);
+
 /* Virtual TPMs */
 int libxl_device_vtpm_add(libxl_ctx *ctx, uint32_t domid, libxl_device_vtpm *vtpm,
                           const libxl_asyncop_how *ao_how)
Index: xen-4.7.0-testing/tools/libxl/libxl_create.c
===================================================================
--- xen-4.7.0-testing.orig/tools/libxl/libxl_create.c
+++ xen-4.7.0-testing/tools/libxl/libxl_create.c
@@ -740,6 +740,8 @@ static void domcreate_bootloader_done(li
 static void domcreate_launch_dm(libxl__egc *egc, libxl__multidev *aodevs,
                                 int ret);
 
+static void domcreate_attach_vscsictrls(libxl__egc *egc, libxl__multidev *multidev,
+                                        int ret);
 static void domcreate_attach_vtpms(libxl__egc *egc, libxl__multidev *multidev,
                                    int ret);
 static void domcreate_attach_usbctrls(libxl__egc *egc,
@@ -1432,13 +1434,13 @@ static void domcreate_devmodel_started(l
     if (d_config->num_nics > 0) {
         /* Attach nics */
         libxl__multidev_begin(ao, &dcs->multidev);
-        dcs->multidev.callback = domcreate_attach_vtpms;
+        dcs->multidev.callback = domcreate_attach_vscsictrls;
         libxl__add_nics(egc, ao, domid, d_config, &dcs->multidev);
         libxl__multidev_prepared(egc, &dcs->multidev, 0);
         return;
     }
 
-    domcreate_attach_vtpms(egc, &dcs->multidev, 0);
+    domcreate_attach_vscsictrls(egc, &dcs->multidev, 0);
     return;
 
 error_out:
@@ -1446,7 +1448,7 @@ error_out:
     domcreate_complete(egc, dcs, ret);
 }
 
-static void domcreate_attach_vtpms(libxl__egc *egc,
+static void domcreate_attach_vscsictrls(libxl__egc *egc,
                                    libxl__multidev *multidev,
                                    int ret)
 {
@@ -1461,6 +1463,39 @@ static void domcreate_attach_vtpms(libxl
        goto error_out;
    }
 
+    /* Plug vscsi devices */
+   if (d_config->num_vscsictrls > 0) {
+       /* Attach vscsictrls */
+       libxl__multidev_begin(ao, &dcs->multidev);
+       dcs->multidev.callback = domcreate_attach_vtpms;
+       libxl__add_vscsictrls(egc, ao, domid, d_config, &dcs->multidev);
+       libxl__multidev_prepared(egc, &dcs->multidev, 0);
+       return;
+   }
+
+   domcreate_attach_vtpms(egc, multidev, 0);
+   return;
+
+error_out:
+   assert(ret);
+   domcreate_complete(egc, dcs, ret);
+}
+
+static void domcreate_attach_vtpms(libxl__egc *egc,
+                                   libxl__multidev *multidev,
+                                   int ret)
+{
+   libxl__domain_create_state *dcs = CONTAINER_OF(multidev, *dcs, multidev);
+   STATE_AO_GC(dcs->ao);
+   int domid = dcs->guest_domid;
+
+   libxl_domain_config* const d_config = dcs->guest_config;
+
+   if(ret) {
+       LOG(ERROR, "unable to add vscsi devices");
+       goto error_out;
+   }
+
     /* Plug vtpm devices */
    if (d_config->num_vtpms > 0) {
        /* Attach vtpms */
Index: xen-4.7.0-testing/tools/libxl/libxl_device.c
===================================================================
--- xen-4.7.0-testing.orig/tools/libxl/libxl_device.c
+++ xen-4.7.0-testing/tools/libxl/libxl_device.c
@@ -616,6 +616,7 @@ void libxl__multidev_prepared(libxl__egc
  * The following functions are defined:
  * libxl__add_disks
  * libxl__add_nics
+ * libxl__add_vscsictrls
  * libxl__add_vtpms
  * libxl__add_usbctrls
  * libxl__add_usbs
@@ -637,6 +638,7 @@ void libxl__multidev_prepared(libxl__egc
 
 DEFINE_DEVICES_ADD(disk)
 DEFINE_DEVICES_ADD(nic)
+DEFINE_DEVICES_ADD(vscsictrl)
 DEFINE_DEVICES_ADD(vtpm)
 DEFINE_DEVICES_ADD(usbctrl)
 DEFINE_DEVICES_ADD(usbdev)
Index: xen-4.7.0-testing/tools/libxl/libxl_internal.h
===================================================================
--- xen-4.7.0-testing.orig/tools/libxl/libxl_internal.h
+++ xen-4.7.0-testing/tools/libxl/libxl_internal.h
@@ -2627,6 +2627,10 @@ _hidden void libxl__device_nic_add(libxl
                                    libxl_device_nic *nic,
                                    libxl__ao_device *aodev);
 
+_hidden void libxl__device_vscsictrl_add(libxl__egc *egc, uint32_t domid,
+                                         libxl_device_vscsictrl *vscsictrl,
+                                         libxl__ao_device *aodev);
+
 _hidden void libxl__device_vtpm_add(libxl__egc *egc, uint32_t domid,
                                    libxl_device_vtpm *vtpm,
                                    libxl__ao_device *aodev);
@@ -3485,6 +3489,10 @@ _hidden void libxl__add_nics(libxl__egc
                              libxl_domain_config *d_config,
                              libxl__multidev *multidev);
 
+_hidden void libxl__add_vscsictrls(libxl__egc *egc, libxl__ao *ao, uint32_t domid,
+                                   libxl_domain_config *d_config,
+                                   libxl__multidev *multidev);
+
 _hidden void libxl__add_vtpms(libxl__egc *egc, libxl__ao *ao, uint32_t domid,
                              libxl_domain_config *d_config,
                              libxl__multidev *multidev);
Index: xen-4.7.0-testing/tools/libxl/libxl_types.idl
===================================================================
--- xen-4.7.0-testing.orig/tools/libxl/libxl_types.idl
+++ xen-4.7.0-testing/tools/libxl/libxl_types.idl
@@ -698,6 +698,43 @@ libxl_device_channel = Struct("device_ch
            ])),
 ])
 
+libxl_vscsi_pdev_type = Enumeration("vscsi_pdev_type", [
+    (0, "INVALID"),
+    (1, "HCTL"),
+    (2, "WWN"),
+    ])
+
+libxl_vscsi_hctl = Struct("vscsi_hctl", [
+    ("hst", uint32),
+    ("chn", uint32),
+    ("tgt", uint32),
+    ("lun", uint64),
+    ])
+
+libxl_vscsi_pdev = Struct("vscsi_pdev", [
+    ("p_devname",        string),
+    ("u", KeyedUnion(None, libxl_vscsi_pdev_type, "type",
+        [
+         ("invalid", None),
+         ("hctl", Struct(None, [("m", libxl_vscsi_hctl)])),
+         ("wwn", Struct(None, [("m", string)])),
+        ])),
+    ])
+
+libxl_device_vscsidev = Struct("device_vscsidev", [
+    ("vscsidev_id",      libxl_devid),
+    ("pdev",             libxl_vscsi_pdev),
+    ("vdev",             libxl_vscsi_hctl),
+    ])
+
+libxl_device_vscsictrl = Struct("device_vscsictrl", [
+    ("backend_domid",    libxl_domid),
+    ("devid",            libxl_devid),
+    ("idx",              libxl_devid),
+    ("vscsidevs",        Array(libxl_device_vscsidev, "num_vscsidevs")),
+    ("scsi_raw_cmds",    libxl_defbool),
+    ])
+
 libxl_domain_config = Struct("domain_config", [
     ("c_info", libxl_domain_create_info),
     ("b_info", libxl_domain_build_info),
@@ -709,6 +746,7 @@ libxl_domain_config = Struct("domain_con
     ("dtdevs", Array(libxl_device_dtdev, "num_dtdevs")),
     ("vfbs", Array(libxl_device_vfb, "num_vfbs")),
     ("vkbs", Array(libxl_device_vkb, "num_vkbs")),
+    ("vscsictrls", Array(libxl_device_vscsictrl, "num_vscsictrls")),
     ("vtpms", Array(libxl_device_vtpm, "num_vtpms")),
     # a channel manifests as a console with a name,
     # see docs/misc/channels.txt
@@ -746,6 +784,21 @@ libxl_nicinfo = Struct("nicinfo", [
     ("rref_rx", integer),
     ], dir=DIR_OUT)
 
+libxl_vscsiinfo = Struct("vscsiinfo", [
+    ("backend", string),
+    ("backend_id", uint32),
+    ("frontend", string),
+    ("frontend_id", uint32),
+    ("devid", libxl_devid),
+    ("pdev", libxl_vscsi_pdev),
+    ("vdev", libxl_vscsi_hctl),
+    ("idx", libxl_devid),
+    ("vscsidev_id", libxl_devid),
+    ("scsi_raw_cmds", bool),
+    ("vscsictrl_state", integer),
+    ("vscsidev_state", integer),
+    ], dir=DIR_OUT)
+
 libxl_vtpminfo = Struct("vtpminfo", [
     ("backend", string),
     ("backend_id", uint32),
Index: xen-4.7.0-testing/tools/libxl/libxl_types_internal.idl
===================================================================
--- xen-4.7.0-testing.orig/tools/libxl/libxl_types_internal.idl
+++ xen-4.7.0-testing/tools/libxl/libxl_types_internal.idl
@@ -24,6 +24,7 @@ libxl__device_kind = Enumeration("device
     (8, "VTPM"),
     (9, "VUSB"),
     (10, "QUSB"),
+    (11, "VSCSI"),
     ])
 
 libxl__console_backend = Enumeration("console_backend", [
Index: xen-4.7.0-testing/tools/libxl/libxl_vscsi.c
===================================================================
--- /dev/null
+++ xen-4.7.0-testing/tools/libxl/libxl_vscsi.c
@@ -0,0 +1,1169 @@
+/*
+ * Copyright (C) 2016      SUSE Linux GmbH
+ * Author Olaf Hering <olaf@aepfle.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; version 2.1 only. with the special
+ * exception on linking described in file LICENSE.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ */
+#include "libxl_osdeps.h" /* must come before any other headers */
+#include "libxl_internal.h"
+
+typedef struct vscsidev_rm {
+    libxl_device_vscsictrl *ctrl;
+    char *be_path;
+    int dev_wait;
+    libxl__device dev;
+} vscsidev_rm_t;
+
+typedef void (*vscsictrl_add)(libxl__egc *egc,
+                              libxl__ao_device *aodev,
+                              libxl_device_vscsictrl *vscsictrl,
+                              libxl_domain_config *d_config);
+
+#define LIBXL_CTRL_INDEX "libxl_ctrl_index"
+
+#define XLU_WWN_LEN 16
+
+static int vscsi_parse_hctl(char *str, libxl_vscsi_hctl *hctl)
+{
+    unsigned int hst, chn, tgt;
+    unsigned long long lun;
+
+    if (sscanf(str, "%u:%u:%u:%llu", &hst, &chn, &tgt, &lun) != 4)
+        return ERROR_INVAL;
+
+    hctl->hst = hst;
+    hctl->chn = chn;
+    hctl->tgt = tgt;
+    hctl->lun = lun;
+    return 0;
+}
+
+/* Translate p-dev back into pdev.type */
+static bool vscsi_parse_pdev(libxl__gc *gc, libxl_device_vscsidev *dev,
+                             char *c, char *p, char *v)
+{
+    libxl_vscsi_hctl hctl;
+    unsigned long long lun;
+    char wwn[XLU_WWN_LEN + 1];
+    bool parsed_ok = false;
+
+    libxl_vscsi_hctl_init(&hctl);
+
+    dev->pdev.p_devname = libxl__strdup(NOGC, c);
+
+    if (strncmp(p, "naa.", 4) == 0) {
+        /* WWN as understood by pvops */
+        memset(wwn, 0, sizeof(wwn));
+        if (sscanf(p, "naa.%16[0-9a-fA-F]:%llu", wwn, &lun) == 2) {
+            libxl_vscsi_pdev_init_type(&dev->pdev, LIBXL_VSCSI_PDEV_TYPE_WWN);
+            dev->pdev.u.wwn.m = libxl__strdup(NOGC, p);
+            parsed_ok = true;
+        }
+    } else if (vscsi_parse_hctl(p, &hctl) == 0) {
+        /* Either xenlinux, or pvops with properly configured alias in sysfs */
+        libxl_vscsi_pdev_init_type(&dev->pdev, LIBXL_VSCSI_PDEV_TYPE_HCTL);
+        libxl_vscsi_hctl_copy(CTX, &dev->pdev.u.hctl.m, &hctl);
+        parsed_ok = true;
+    }
+
+    if (parsed_ok && vscsi_parse_hctl(v, &dev->vdev) != 0)
+        parsed_ok = false;
+
+    libxl_vscsi_hctl_dispose(&hctl);
+
+    return parsed_ok;
+}
+
+static bool vscsi_fill_dev(libxl__gc *gc,
+                           xs_transaction_t t,
+                           const char *devs_path,
+                           const char *dev_dir,
+                           libxl_device_vscsidev *dev)
+{
+    char *path, *c, *p, *v, *s;
+    unsigned int devid;
+    int r;
+
+    r = sscanf(dev_dir, "dev-%u", &devid);
+    if (r != 1) {
+        LOG(ERROR, "expected dev-N, got '%s'", dev_dir);
+        return false;
+    }
+    dev->vscsidev_id = devid;
+
+    path = GCSPRINTF("%s/%s", devs_path, dev_dir);
+    c = libxl__xs_read(gc, t, GCSPRINTF("%s/p-devname", path));
+    p = libxl__xs_read(gc, t, GCSPRINTF("%s/p-dev", path));
+    v = libxl__xs_read(gc, t, GCSPRINTF("%s/v-dev", path));
+    s = libxl__xs_read(gc, t, GCSPRINTF("%s/state", path));
+    LOG(DEBUG, "%s/state is %s", path, s);
+    if (!(c && p && v && s)) {
+        LOG(ERROR, "p-devname '%s' p-dev '%s' v-dev '%s'", c, p, v);
+        return false;
+    }
+
+    if (!vscsi_parse_pdev(gc, dev, c, p, v)) {
+        LOG(ERROR, "failed to parse %s: %s %s %s %s", path, c, p, v, s);
+        return false;
+    }
+
+    return true;
+}
+
+static bool vscsi_fill_ctrl(libxl__gc *gc,
+                            uint32_t tgt_domid,
+                            xs_transaction_t t,
+                            const char *fe_path,
+                            const char *dir,
+                            libxl_device_vscsictrl *ctrl)
+{
+    libxl_device_vscsidev dev;
+    char *tmp, *devs_path;
+    const char *be_path;
+    char **dev_dirs;
+    unsigned int ndev_dirs, dev_dir;
+    uint32_t be_domid, fe_domid;
+    char be_type[16];
+    int r;
+    bool ok;
+
+    ctrl->devid = atoi(dir);
+
+    tmp = GCSPRINTF("%s/%s/backend", fe_path, dir);
+    r = libxl__xs_read_checked(gc, t, tmp, &be_path);
+    if (r || !be_path)
+        goto out;
+
+    r = sscanf(be_path, "/local/domain/%u/backend/%15[^/]/%u",
+               &be_domid, be_type, &fe_domid);
+    if (r != 3 || fe_domid != tgt_domid)
+        goto out;
+    ctrl->backend_domid = be_domid;
+
+    tmp = libxl__xs_read(gc, t, GCSPRINTF("%s/" LIBXL_CTRL_INDEX, be_path));
+    if (!tmp)
+        goto out;
+    ctrl->idx = atoi(tmp);
+
+    tmp = libxl__xs_read(gc, t, GCSPRINTF("%s/feature-host", be_path));
+    if (!tmp)
+        goto out;
+    ok = atoi(tmp) != 0;
+    libxl_defbool_set(&ctrl->scsi_raw_cmds, ok);
+
+    ok = true;
+    devs_path = GCSPRINTF("%s/vscsi-devs", be_path);
+    dev_dirs = libxl__xs_directory(gc, t, devs_path, &ndev_dirs);
+    for (dev_dir = 0; dev_dirs && dev_dir < ndev_dirs; dev_dir++) {
+        libxl_device_vscsidev_init(&dev);
+        ok = vscsi_fill_dev(gc, t, devs_path, dev_dirs[dev_dir], &dev);
+        if (ok == true)
+            ok = ctrl->idx == dev.vdev.hst;
+        if (ok == true)
+            libxl_device_vscsictrl_append_vscsidev(CTX, ctrl, &dev);
+        libxl_device_vscsidev_dispose(&dev);
+        if (ok == false)
+            break;
+    }
+
+    return ok;
+
+out:
+    libxl_defbool_set(&ctrl->scsi_raw_cmds, false);
+    return false;
+}
+
+/* return an array of vscsictrls with num elements */
+static int vscsi_collect_ctrls(libxl__gc *gc,
+                               uint32_t domid,
+                               libxl_device_vscsictrl **ctrls,
+                               int *num)
+{
+    xs_transaction_t t = XBT_NULL;
+    libxl_device_vscsictrl ctrl;
+    char *fe_path;
+    char **dirs;
+    unsigned int ndirs = 0, dir;
+    int rc;
+
+    fe_path = GCSPRINTF("%s/device/vscsi", libxl__xs_get_dompath(gc, domid));
+
+    for (;;) {
+        *num = 0;
+
+        rc = libxl__xs_transaction_start(gc, &t);
+        if (rc) goto out;
+
+        dirs = libxl__xs_directory(gc, t, fe_path, &ndirs);
+        /* Nothing to do */
+        if (!(dirs && ndirs))
+            break;
+
+        /* List of ctrls to be returned to the caller */
+        *ctrls = libxl__malloc(NOGC, ndirs * sizeof(**ctrls));
+
+        for (dir = 0; dir < ndirs; dir++) {
+            libxl_device_vscsictrl_init(*ctrls + dir);
+
+            libxl_device_vscsictrl_init(&ctrl);
+            if (vscsi_fill_ctrl(gc, domid, t, fe_path, dirs[dir], &ctrl)) {
+                libxl_device_vscsictrl_copy(CTX, *ctrls + *num, &ctrl);
+                (*num)++;
+            }
+            libxl_device_vscsictrl_dispose(&ctrl);
+        }
+
+        rc = libxl__xs_transaction_commit(gc, &t);
+        if (!rc) break;
+
+        if (rc < 0) {
+            for (dir = 0; dir < ndirs; dir++)
+                libxl_device_vscsictrl_dispose(*ctrls + dir);
+            free(*ctrls);
+            *ctrls = NULL;
+            *num = 0;
+            goto out;
+        }
+    }
+
+out:
+    libxl__xs_transaction_abort(gc, &t);
+    return rc;
+}
+
+/* Simplified variant of device_addrm_aocomplete */
+static void vscsi_aodev_complete(libxl__egc *egc, libxl__ao_device *aodev)
+{
+    STATE_AO_GC(aodev->ao);
+    libxl__ao_complete(egc, ao, aodev->rc);
+}
+
+static int libxl__device_from_vscsictrl(libxl__gc *gc, uint32_t domid,
+                                        libxl_device_vscsictrl *vscsictrl,
+                                        libxl__device *device)
+{
+    device->backend_devid = vscsictrl->devid;
+    device->backend_domid = vscsictrl->backend_domid;
+    device->devid         = vscsictrl->devid;
+    device->domid         = domid;
+    device->backend_kind  = LIBXL__DEVICE_KIND_VSCSI;
+    device->kind          = LIBXL__DEVICE_KIND_VSCSI;
+
+    return 0;
+}
+
+static int vscsictrl_remove(libxl_ctx *ctx,
+                            uint32_t domid,
+                            libxl_device_vscsictrl *vscsictrl,
+                            const libxl_asyncop_how *ao_how,
+                            int force)
+{
+    AO_CREATE(ctx, domid, ao_how);
+    libxl__device *device;
+    libxl__ao_device *aodev;
+    int rc;
+
+    GCNEW(device);
+    rc = libxl__device_from_vscsictrl(gc, domid, vscsictrl, device);
+    if (rc != 0) goto out;
+
+    GCNEW(aodev);
+    libxl__prepare_ao_device(ao, aodev);
+    aodev->action = LIBXL__DEVICE_ACTION_REMOVE;
+    aodev->dev = device;
+    aodev->callback = vscsi_aodev_complete;
+    aodev->force = force;
+    libxl__initiate_device_generic_remove(egc, aodev);
+
+out:
+    if (rc) return AO_CREATE_FAIL(rc);
+    return AO_INPROGRESS;
+}
+
+static int vscsidev_be_set_rm(libxl__gc *gc,
+                              libxl_device_vscsidev *v,
+                              flexarray_t *back)
+{
+    int rc;
+    char *dir;
+
+    dir = GCSPRINTF("vscsi-devs/dev-%u", v->vscsidev_id);
+    rc = flexarray_append_pair(back,
+                               GCSPRINTF("%s/state", dir),
+                               GCSPRINTF("%d", XenbusStateClosing));
+    return rc;
+}
+
+static int vscsictrl_reconfigure_rm(libxl__ao_device *aodev,
+                                    const char *state_path,
+                                    int *be_wait)
+
+{
+    STATE_AO_GC(aodev->ao);
+    vscsidev_rm_t *vscsidev_rm = CONTAINER_OF(aodev->dev, *vscsidev_rm, dev);
+    libxl_device_vscsictrl *ctrl = vscsidev_rm->ctrl;
+    const char *be_path = vscsidev_rm->be_path;
+    int rc, i, be_state;
+    char *dev_path, *state_val;
+    flexarray_t *back;
+    libxl_device_vscsidev *v;
+    xs_transaction_t t = XBT_NULL;
+
+    /* Prealloc key+value: 1 toplevel + 1 per device */
+    i = 2 * (1 + 1);
+    back = flexarray_make(gc, i, 1);
+
+    for (;;) {
+        rc = libxl__xs_transaction_start(gc, &t);
+        if (rc) goto out;
+
+        state_val = libxl__xs_read(gc, t, state_path);
+        LOG(DEBUG, "%s is %s", state_path, state_val);
+        if (!state_val) {
+            rc = ERROR_NOTFOUND;
+            goto out;
+        }
+
+        be_state = atoi(state_val);
+        switch (be_state) {
+        case XenbusStateUnknown:
+        case XenbusStateInitialising:
+        case XenbusStateClosing:
+        case XenbusStateClosed:
+        default:
+            /* The backend is in a bad state */
+            rc = ERROR_FAIL;
+            goto out;
+        case XenbusStateInitialised:
+        case XenbusStateReconfiguring:
+        case XenbusStateReconfigured:
+            /* Backend is still busy, caller has to retry */
+            rc = ERROR_NOT_READY;
+            goto out;
+        case XenbusStateInitWait:
+            /* The frontend did not connect yet */
+            *be_wait = XenbusStateInitWait;
+            vscsidev_rm->dev_wait = XenbusStateClosing;
+            break;
+        case XenbusStateConnected:
+            /* The backend can handle reconfigure */
+            *be_wait = XenbusStateConnected;
+            vscsidev_rm->dev_wait = XenbusStateClosed;
+            flexarray_append_pair(back, "state",
+                                  GCSPRINTF("%d", XenbusStateReconfiguring));
+            break;
+        }
+
+        /* Append new vscsidev or skip existing  */
+        for (i = 0; i < ctrl->num_vscsidevs; i++) {
+            unsigned int nb = 0;
+            v = ctrl->vscsidevs + i;
+            dev_path = GCSPRINTF("%s/vscsi-devs/dev-%u", be_path, v->vscsidev_id);
+            if (!libxl__xs_directory(gc, XBT_NULL, dev_path, &nb)) {
+                /* FIXME Sanity check */
+                LOG(DEBUG, "%s does not exist anymore", dev_path);
+                continue;
+            }
+            rc = vscsidev_be_set_rm(gc, v, back);
+            if (rc) goto out;
+        }
+
+        libxl__xs_writev(gc, t, be_path,
+                         libxl__xs_kvs_of_flexarray(gc, back, back->count));
+
+        rc = libxl__xs_transaction_commit(gc, &t);
+        if (!rc) break;
+        if (rc < 0) goto out;
+    }
+
+    rc = 0;
+
+out:
+    libxl__xs_transaction_abort(gc, &t);
+    return rc;
+}
+
+static void vscsictrl_remove_be_dev(libxl__gc *gc,
+                                    libxl_device_vscsidev *v,
+                                    xs_transaction_t t,
+                                    const char *be_path,
+                                    int dev_wait)
+{
+    char *dir, *path, *val;
+
+    dir = GCSPRINTF("%s/vscsi-devs/dev-%u", be_path, v->vscsidev_id);
+    path = GCSPRINTF("%s/state", dir);
+    val = libxl__xs_read(gc, t, path);
+    LOG(DEBUG, "%s is %s", path, val);
+    if (val && strcmp(val, GCSPRINTF("%d", dev_wait)) == 0) {
+        xs_rm(CTX->xsh, t, GCSPRINTF("%s/state", dir));
+        xs_rm(CTX->xsh, t, GCSPRINTF("%s/p-devname", dir));
+        xs_rm(CTX->xsh, t, GCSPRINTF("%s/p-dev", dir));
+        xs_rm(CTX->xsh, t, GCSPRINTF("%s/v-dev", dir));
+        xs_rm(CTX->xsh, t, dir);
+    } else {
+        LOG(ERROR, "%s has %s, expected %d", path, val, dev_wait);
+    }
+}
+
+static void vscsictrl_remove_be_cb(libxl__egc *egc,
+                                   libxl__ev_devstate *ds,
+                                   int rc)
+{
+    libxl__ao_device *aodev = CONTAINER_OF(ds, *aodev, backend_ds);
+    STATE_AO_GC(aodev->ao);
+    vscsidev_rm_t *vscsidev_rm = CONTAINER_OF(aodev->dev, *vscsidev_rm, dev);
+    libxl_device_vscsictrl *ctrl = vscsidev_rm->ctrl;
+    xs_transaction_t t = XBT_NULL;
+    int i;
+
+    for (;;) {
+        rc = libxl__xs_transaction_start(gc, &t);
+        if (rc) goto out;
+
+        for (i = 0; i < ctrl->num_vscsidevs; i++)
+            vscsictrl_remove_be_dev(gc, ctrl->vscsidevs + i, t,
+                                    vscsidev_rm->be_path,
+                                    vscsidev_rm->dev_wait);
+
+        rc = libxl__xs_transaction_commit(gc, &t);
+        if (!rc) break;
+        if (rc < 0) goto out;
+    }
+
+out:
+    aodev->rc = rc;
+    aodev->callback(egc, aodev);
+}
+
+static void vscsidev__remove(libxl__egc *egc, libxl__ao_device *aodev)
+{
+    STATE_AO_GC(aodev->ao);
+    vscsidev_rm_t *vscsidev_rm = CONTAINER_OF(aodev->dev, *vscsidev_rm, dev);
+    char *state_path;
+    int rc, be_wait;
+
+    vscsidev_rm->be_path = libxl__device_backend_path(gc, aodev->dev);
+    state_path = GCSPRINTF("%s/state", vscsidev_rm->be_path);
+
+    rc = vscsictrl_reconfigure_rm(aodev, state_path, &be_wait);
+    if (rc) goto out;
+
+    rc = libxl__ev_devstate_wait(ao, &aodev->backend_ds,
+                                 vscsictrl_remove_be_cb,
+                                 state_path, be_wait,
+                                 LIBXL_DESTROY_TIMEOUT * 1000);
+    if (rc) {
+        LOG(ERROR, "unable to wait for %s", state_path);
+        goto out;
+    }
+
+    return;
+
+out:
+    aodev->rc = rc;
+    /* Notify that this is done */
+    aodev->callback(egc, aodev);
+}
+
+static int vscsidev_remove(libxl_ctx *ctx,
+                           uint32_t domid,
+                           libxl_device_vscsictrl *vscsictrl,
+                           const libxl_asyncop_how *ao_how)
+{
+    AO_CREATE(ctx, domid, ao_how);
+    libxl__ao_device *aodev;
+    vscsidev_rm_t *vscsidev_rm;
+    libxl__device *device;
+    int rc;
+
+    GCNEW(aodev);
+
+    GCNEW(vscsidev_rm);
+    vscsidev_rm->ctrl = vscsictrl;
+    device = &vscsidev_rm->dev;
+
+    rc = libxl__device_from_vscsictrl(gc, domid, vscsictrl, device);
+    if (rc) goto out;
+
+    libxl__prepare_ao_device(ao, aodev);
+    aodev->dev = device;
+    aodev->action = LIBXL__DEVICE_ACTION_REMOVE;
+    aodev->callback = vscsi_aodev_complete;
+
+    vscsidev__remove(egc, aodev);
+
+out:
+    if (rc) AO_CREATE_FAIL(rc);
+    return AO_INPROGRESS;
+}
+
+static int vscsidev_backend_add(libxl__gc *gc,
+                                libxl_device_vscsidev *v,
+                                flexarray_t *back)
+{
+    int rc;
+    char *dir;
+    unsigned int hst, chn, tgt;
+    unsigned long long lun;
+
+
+    dir = GCSPRINTF("vscsi-devs/dev-%u", v->vscsidev_id);
+    switch (v->pdev.type) {
+    case LIBXL_VSCSI_PDEV_TYPE_WWN:
+        flexarray_append_pair(back,
+                              GCSPRINTF("%s/p-dev", dir),
+                              v->pdev.u.wwn.m);
+        break;
+    case LIBXL_VSCSI_PDEV_TYPE_HCTL:
+        hst = v->pdev.u.hctl.m.hst;
+        chn = v->pdev.u.hctl.m.chn;
+        tgt = v->pdev.u.hctl.m.tgt;
+        lun = v->pdev.u.hctl.m.lun;
+        flexarray_append_pair(back,
+                              GCSPRINTF("%s/p-dev", dir),
+                              GCSPRINTF("%u:%u:%u:%llu", hst, chn, tgt, lun));
+        break;
+    case LIBXL_VSCSI_PDEV_TYPE_INVALID:
+        /* fallthrough */
+    default:
+        rc = ERROR_FAIL;
+        goto out;
+    }
+    flexarray_append_pair(back,
+                          GCSPRINTF("%s/p-devname", dir),
+                          v->pdev.p_devname);
+    hst = v->vdev.hst;
+    chn = v->vdev.chn;
+    tgt = v->vdev.tgt;
+    lun = v->vdev.lun;
+    flexarray_append_pair(back,
+                          GCSPRINTF("%s/v-dev", dir),
+                          GCSPRINTF("%u:%u:%u:%llu", hst, chn, tgt, lun));
+    flexarray_append_pair(back,
+                          GCSPRINTF("%s/state", dir),
+                          GCSPRINTF("%d", XenbusStateInitialising));
+    rc = 0;
+out:
+    return rc;
+}
+
+static void vscsictrl_new_backend(libxl__egc *egc,
+                                  libxl__ao_device *aodev,
+                                  libxl_device_vscsictrl *vscsictrl,
+                                  libxl_domain_config *d_config)
+{
+    STATE_AO_GC(aodev->ao);
+    int rc, i;
+    flexarray_t *back;
+    flexarray_t *front;
+    libxl_device_vscsidev *v;
+    xs_transaction_t t = XBT_NULL;
+
+    /* Prealloc key+value: 4 toplevel + 4 per device */
+    i = 2 * (4 + (4 * vscsictrl->num_vscsidevs));
+    back = flexarray_make(gc, i, 1);
+    front = flexarray_make(gc, 2 * 2, 1);
+
+    flexarray_append_pair(back,
+                          "frontend-id",
+                          GCSPRINTF("%d", aodev->dev->domid));
+    flexarray_append_pair(back, "online", "1");
+    flexarray_append_pair(back,
+                          "state",
+                          GCSPRINTF("%d", XenbusStateInitialising));
+    flexarray_append_pair(back,
+                          LIBXL_CTRL_INDEX,
+                          GCSPRINTF("%d", vscsictrl->idx));
+    flexarray_append_pair(back, "feature-host",
+                          libxl_defbool_val(vscsictrl->scsi_raw_cmds) ?
+                          "1" : "0");
+
+    flexarray_append_pair(front,
+                          "backend-id",
+                          GCSPRINTF("%d", vscsictrl->backend_domid));
+    flexarray_append_pair(front,
+                          "state",
+                          GCSPRINTF("%d", XenbusStateInitialising));
+
+    for (i = 0; i < vscsictrl->num_vscsidevs; i++) {
+        v = vscsictrl->vscsidevs + i;
+        rc = vscsidev_backend_add(gc, v, back);
+        if (rc) goto out;
+    }
+
+    for (;;) {
+        rc = libxl__xs_transaction_start(gc, &t);
+        if (rc) goto out;
+
+        rc = libxl__device_exists(gc, t, aodev->dev);
+        if (rc < 0) goto out;
+        if (rc == 1) {              /* already exists in xenstore */
+            LOG(ERROR, "device already exists in xenstore");
+            rc = ERROR_DEVICE_EXISTS;
+            goto out;
+        }
+
+        if (aodev->update_json) {
+            rc = libxl__set_domain_configuration(gc, aodev->dev->domid, d_config);
+            if (rc) goto out;
+        }
+
+        libxl__device_generic_add(gc, t, aodev->dev,
+                                  libxl__xs_kvs_of_flexarray(gc, back,
+                                                             back->count),
+                                  libxl__xs_kvs_of_flexarray(gc, front,
+                                                             front->count),
+                                  NULL);
+
+        rc = libxl__xs_transaction_commit(gc, &t);
+        if (!rc) break;
+        if (rc < 0) goto out;
+    }
+
+    libxl__wait_device_connection(egc, aodev);
+    return;
+
+out:
+    libxl__xs_transaction_abort(gc, &t);
+    aodev->rc = rc;
+    aodev->callback(egc, aodev);
+}
+
+static void vscsictrl_do_reconfigure_add_cb(libxl__egc *egc,
+                                            libxl__ev_devstate *ds,
+                                            int rc)
+{
+    libxl__ao_device *aodev = CONTAINER_OF(ds, *aodev, backend_ds);
+    STATE_AO_GC(aodev->ao);
+    aodev->rc = rc;
+    aodev->callback(egc, aodev);
+}
+
+static void vscsictrl_do_reconfigure_add(libxl__egc *egc,
+                                         libxl__ao_device *aodev,
+                                         libxl_device_vscsictrl *vscsictrl,
+                                         libxl_domain_config *d_config)
+{
+    STATE_AO_GC(aodev->ao);
+    int rc, i, be_state, be_wait;
+    const char *be_path;
+    char *dev_path, *state_path, *state_val;
+    flexarray_t *back;
+    libxl_device_vscsidev *v;
+    xs_transaction_t t = XBT_NULL;
+    bool do_reconfigure = false;
+
+    /* Prealloc key+value: 1 toplevel + 4 per device */
+    i = 2 * (1 + (4 * vscsictrl->num_vscsidevs));
+    back = flexarray_make(gc, i, 1);
+
+    be_path = libxl__device_backend_path(gc, aodev->dev);
+    state_path = GCSPRINTF("%s/state", be_path);
+
+    for (;;) {
+        rc = libxl__xs_transaction_start(gc, &t);
+        if (rc) goto out;
+
+        state_val = libxl__xs_read(gc, t, state_path);
+        LOG(DEBUG, "%s is %s", state_path, state_val);
+        if (!state_val) {
+            rc = ERROR_FAIL;
+            goto out;
+        }
+
+        be_state = atoi(state_val);
+        switch (be_state) {
+        case XenbusStateUnknown:
+        case XenbusStateInitialising:
+        case XenbusStateClosing:
+        case XenbusStateClosed:
+        default:
+            /* The backend is in a bad state */
+            rc = ERROR_FAIL;
+            goto out;
+        case XenbusStateInitialised:
+        case XenbusStateReconfiguring:
+        case XenbusStateReconfigured:
+            /* Backend is still busy, caller has to retry */
+            rc = ERROR_NOT_READY;
+            goto out;
+        case XenbusStateInitWait:
+            /* The frontend did not connect yet */
+            be_wait = XenbusStateInitWait;
+            do_reconfigure = false;
+            break;
+        case XenbusStateConnected:
+            /* The backend can handle reconfigure */
+            be_wait = XenbusStateConnected;
+            flexarray_append_pair(back, "state", GCSPRINTF("%d", XenbusStateReconfiguring));
+            do_reconfigure = true;
+            break;
+        }
+
+        /* Append new vscsidev or skip existing  */
+        for (i = 0; i < vscsictrl->num_vscsidevs; i++) {
+            unsigned int nb = 0;
+            v = vscsictrl->vscsidevs + i;
+            dev_path = GCSPRINTF("%s/vscsi-devs/dev-%u", be_path, v->vscsidev_id);
+            if (libxl__xs_directory(gc, XBT_NULL, dev_path, &nb)) {
+                /* FIXME Sanity check */
+                LOG(DEBUG, "%s exists already with %u entries", dev_path, nb);
+                continue;
+            }
+            rc = vscsidev_backend_add(gc, v, back);
+            if (rc) goto out;
+        }
+
+        if (aodev->update_json) {
+            rc = libxl__set_domain_configuration(gc, aodev->dev->domid, d_config);
+            if (rc) goto out;
+        }
+
+        libxl__xs_writev(gc, t, be_path,
+                         libxl__xs_kvs_of_flexarray(gc, back, back->count));
+
+        rc = libxl__xs_transaction_commit(gc, &t);
+        if (!rc) break;
+        if (rc < 0) goto out;
+    }
+
+    if (do_reconfigure) {
+        rc = libxl__ev_devstate_wait(ao, &aodev->backend_ds,
+                                     vscsictrl_do_reconfigure_add_cb,
+                                     state_path, be_wait,
+                                     LIBXL_INIT_TIMEOUT * 1000);
+        if (rc) goto out;
+    }
+    return;
+
+out:
+    libxl__xs_transaction_abort(gc, &t);
+    aodev->rc = rc;
+    aodev->callback(egc, aodev);
+}
+
+static int vscsictrl_next_vscsidev_id(libxl__gc *gc,
+                                      const char *libxl_path,
+                                      libxl_devid *vscsidev_id)
+{
+    const char *val;
+    xs_transaction_t t = XBT_NULL;
+    unsigned int id;
+    int rc;
+
+    for (;;) {
+        rc = libxl__xs_transaction_start(gc, &t);
+        if (rc) goto out;
+
+        val = libxl__xs_read(gc, t, libxl_path);
+        id = val ? strtoul(val, NULL, 10) : 0;
+
+        LOG(DEBUG, "%s = %s vscsidev_id %u", libxl_path, val, id);
+
+        val = GCSPRINTF("%u", id + 1);
+        rc = libxl__xs_write_checked(gc, t, libxl_path, val);
+        if (rc) goto out;
+
+        rc = libxl__xs_transaction_commit(gc, &t);
+        if (!rc) break;
+        if (rc < 0) goto out;
+    }
+
+    *vscsidev_id = id;
+    rc = 0;
+
+out:
+    libxl__xs_transaction_abort(gc, &t);
+    return rc;
+}
+
+static int vscsictrl_assign_vscsidev_ids(libxl__gc *gc,
+                                         uint32_t domid,
+                                         libxl_device_vscsictrl *vscsictrl)
+{
+    libxl_device_vscsidev *dev;
+    libxl_devid vscsidev_id;
+    const char *libxl_path;
+    int rc, i;
+
+    libxl_path = GCSPRINTF("%s/vscsi/%u/next_vscsidev_id",
+                           libxl__xs_libxl_path(gc, domid),
+                           vscsictrl->devid);
+    for (i = 0; i < vscsictrl->num_vscsidevs; i++) {
+        dev = &vscsictrl->vscsidevs[i];
+        if (dev->vscsidev_id >= 0)
+            continue;
+        rc = vscsictrl_next_vscsidev_id(gc, libxl_path, &vscsidev_id);
+        if (rc) {
+            LOG(ERROR, "failed to assign vscsidev_id to %s for %s",
+                libxl_path, dev->pdev.p_devname);
+            goto out;
+        }
+        dev->vscsidev_id = vscsidev_id;
+    }
+
+    rc = 0;
+out:
+    return rc;
+}
+
+static void vscsictrl_update_json(libxl__egc *egc,
+                                  libxl__ao_device *aodev,
+                                  libxl_device_vscsictrl *vscsictrl,
+                                  vscsictrl_add fn)
+{
+    STATE_AO_GC(aodev->ao);
+    int rc;
+    uint32_t domid = aodev->dev->domid;
+    libxl_device_vscsictrl vscsictrl_saved;
+    libxl_domain_config d_config;
+    libxl__domain_userdata_lock *lock = NULL;
+
+    libxl_domain_config_init(&d_config);
+    libxl_device_vscsictrl_init(&vscsictrl_saved);
+
+    libxl_device_vscsictrl_copy(CTX, &vscsictrl_saved, vscsictrl);
+
+    rc = vscsictrl_assign_vscsidev_ids(gc, domid, &vscsictrl_saved);
+    if (rc) goto out;
+
+    if (aodev->update_json) {
+        lock = libxl__lock_domain_userdata(gc, domid);
+        if (!lock) {
+            rc = ERROR_LOCK_FAIL;
+            goto out;
+        }
+
+        rc = libxl__get_domain_configuration(gc, domid, &d_config);
+        if (rc) goto out;
+
+        /* Replace or append the copy to the domain config */
+        DEVICE_ADD(vscsictrl, vscsictrls, domid, &vscsictrl_saved, COMPARE_DEVID, &d_config);
+    }
+
+    fn(egc, aodev, &vscsictrl_saved, &d_config);
+
+out:
+    if (lock) libxl__unlock_domain_userdata(lock);
+    libxl_device_vscsictrl_dispose(&vscsictrl_saved);
+    libxl_domain_config_dispose(&d_config);
+    if (rc) {
+        aodev->rc = rc;
+        aodev->callback(egc, aodev);
+    }
+}
+
+static void vscsictrl__reconfigure_add(libxl__egc *egc,
+                                       uint32_t domid,
+                                       libxl_device_vscsictrl *vscsictrl,
+                                       libxl__ao_device *aodev)
+{
+    STATE_AO_GC(aodev->ao);
+    libxl__device *device;
+    vscsictrl_add fn;
+    int rc;
+
+    GCNEW(device);
+    rc = libxl__device_from_vscsictrl(gc, domid, vscsictrl, device);
+    if (rc) goto out;
+    aodev->dev = device;
+
+    fn = vscsictrl_do_reconfigure_add;
+    vscsictrl_update_json(egc, aodev, vscsictrl, fn);
+    return;
+
+out:
+    aodev->rc = rc;
+    aodev->callback(egc, aodev);
+}
+
+static int vscsictrl_reconfigure_add(libxl_ctx *ctx,
+                                     uint32_t domid,
+                                     libxl_device_vscsictrl *vscsictrl,
+                                     const libxl_asyncop_how *ao_how)
+{
+    AO_CREATE(ctx, domid, ao_how);
+    libxl__ao_device *aodev;
+
+    GCNEW(aodev);
+    libxl__prepare_ao_device(ao, aodev);
+    aodev->action = LIBXL__DEVICE_ACTION_ADD;
+    aodev->callback = vscsi_aodev_complete;
+    aodev->update_json = true;
+    vscsictrl__reconfigure_add(egc, domid, vscsictrl, aodev);
+
+    return AO_INPROGRESS;
+}
+
+void libxl__device_vscsictrl_add(libxl__egc *egc, uint32_t domid,
+                                 libxl_device_vscsictrl *vscsictrl,
+                                 libxl__ao_device *aodev)
+{
+    STATE_AO_GC(aodev->ao);
+    libxl__device *device;
+    vscsictrl_add fn;
+    int rc;
+
+    if (vscsictrl->devid == -1) {
+        if ((vscsictrl->devid = libxl__device_nextid(gc, domid, "vscsi")) < 0) {
+            rc = ERROR_FAIL;
+            goto out;
+        }
+    }
+
+    GCNEW(device);
+    rc = libxl__device_from_vscsictrl(gc, domid, vscsictrl, device);
+    if (rc) goto out;
+    aodev->dev = device;
+
+    fn = vscsictrl_new_backend;
+    vscsictrl_update_json(egc, aodev, vscsictrl, fn);
+    return;
+
+out:
+    aodev->rc = rc;
+    aodev->callback(egc, aodev);
+}
+
+int libxl_device_vscsictrl_remove(libxl_ctx *ctx, uint32_t domid,
+                                  libxl_device_vscsictrl *vscsictrl,
+                                  const libxl_asyncop_how *ao_how)
+{
+    return vscsictrl_remove(ctx, domid, vscsictrl, ao_how, 0);
+}
+
+int libxl_device_vscsictrl_destroy(libxl_ctx *ctx, uint32_t domid,
+                                   libxl_device_vscsictrl *vscsictrl,
+                                   const libxl_asyncop_how *ao_how)
+{
+    return vscsictrl_remove(ctx, domid, vscsictrl, ao_how, 1);
+}
+
+libxl_device_vscsictrl *libxl_device_vscsictrl_list(libxl_ctx *ctx,
+                                                    uint32_t domid,
+                                                    int *num)
+{
+    GC_INIT(ctx);
+    libxl_device_vscsictrl *ctrls = NULL;
+    int rc, num_ctrls = 0;
+
+    *num = 0;
+
+    rc = vscsi_collect_ctrls(gc, domid, &ctrls, &num_ctrls);
+    if (rc == 0)
+        *num = num_ctrls;
+
+    GC_FREE;
+    return ctrls;
+}
+
+int libxl_device_vscsictrl_getinfo(libxl_ctx *ctx, uint32_t domid,
+                                   libxl_device_vscsictrl *vscsictrl,
+                                   libxl_device_vscsidev *vscsidev,
+                                   libxl_vscsiinfo *vscsiinfo)
+{
+    GC_INIT(ctx);
+    char *dompath, *vscsipath;
+    char *val;
+    int rc = ERROR_FAIL;
+
+    libxl_vscsiinfo_init(vscsiinfo);
+    dompath = libxl__xs_get_dompath(gc, domid);
+    vscsiinfo->devid = vscsictrl->devid;
+    vscsiinfo->vscsidev_id = vscsidev->vscsidev_id;
+    libxl_vscsi_pdev_copy(ctx, &vscsiinfo->pdev, &vscsidev->pdev);
+    libxl_vscsi_hctl_copy(ctx, &vscsiinfo->vdev, &vscsidev->vdev);
+
+    vscsipath = GCSPRINTF("%s/device/vscsi/%d", dompath, vscsiinfo->devid);
+    vscsiinfo->backend = xs_read(ctx->xsh, XBT_NULL,
+                                 GCSPRINTF("%s/backend", vscsipath), NULL);
+    if (!vscsiinfo->backend)
+        goto out;
+    if(!libxl__xs_read(gc, XBT_NULL, vscsiinfo->backend))
+        goto out;
+
+    val = libxl__xs_read(gc, XBT_NULL, GCSPRINTF("%s/backend-id", vscsipath));
+    vscsiinfo->backend_id = val ? strtoul(val, NULL, 10) : -1;
+
+    val = libxl__xs_read(gc, XBT_NULL, GCSPRINTF("%s/state", vscsipath));
+    vscsiinfo->vscsictrl_state = val ? strtoul(val, NULL, 10) : -1;
+
+    val = libxl__xs_read(gc, XBT_NULL, GCSPRINTF("%s/" LIBXL_CTRL_INDEX, vscsipath));
+    vscsiinfo->idx = val ? strtoul(val, NULL, 10) : -1;
+
+    vscsiinfo->frontend = xs_read(ctx->xsh, XBT_NULL,
+                                  GCSPRINTF("%s/frontend", vscsiinfo->backend), NULL);
+
+    val = libxl__xs_read(gc, XBT_NULL,
+                         GCSPRINTF("%s/frontend-id", vscsiinfo->backend));
+    vscsiinfo->frontend_id = val ? strtoul(val, NULL, 10) : -1;
+
+    val = libxl__xs_read(gc, XBT_NULL,
+                         GCSPRINTF("%s/vscsi-devs/dev-%u/state",
+                         vscsiinfo->backend, vscsidev->vscsidev_id));
+    vscsiinfo->vscsidev_state = val ? strtoul(val, NULL, 10) : -1;
+
+    rc = 0;
+out:
+    GC_FREE;
+    return rc;
+}
+
+int libxl_device_vscsidev_add(libxl_ctx *ctx, uint32_t domid,
+                              libxl_device_vscsidev *vscsidev,
+                              const libxl_asyncop_how *ao_how)
+{
+    GC_INIT(ctx);
+    libxl_device_vscsictrl *vc, *ctrls = NULL;
+    libxl_device_vscsidev *vd;
+    int c, d, rc, num_ctrls = 0;
+    int duplicate = 0;
+
+    rc = vscsi_collect_ctrls(gc, domid, &ctrls, &num_ctrls);
+    if (rc != 0) goto out;
+
+
+    for (c = 0; c < num_ctrls; ++c) {
+        vc = ctrls + c;
+        if (vc->idx != vscsidev->vdev.hst)
+            continue;
+
+        for (d = 0; d < vc->num_vscsidevs; d++) {
+            vd = vc->vscsidevs + d;
+            if (vd->vdev.hst == vscsidev->vdev.hst &&
+                vd->vdev.chn == vscsidev->vdev.chn &&
+                vd->vdev.tgt == vscsidev->vdev.tgt &&
+                vd->vdev.lun == vscsidev->vdev.lun) {
+                unsigned long long lun = vd->vdev.lun;
+                LOG(ERROR, "vdev '%u:%u:%u:%llu' is already used.\n",
+                    vd->vdev.hst, vd->vdev.chn, vd->vdev.tgt, lun);
+                rc = ERROR_DEVICE_EXISTS;
+                duplicate = 1;
+                break;
+            }
+        }
+
+        if (!duplicate) {
+            /* Append vscsidev to this vscsictrl, trigger reconfigure */
+            libxl_device_vscsictrl_append_vscsidev(ctx, vc, vscsidev);
+            rc = vscsictrl_reconfigure_add(ctx, domid, vc, ao_how);
+        }
+        break;
+    }
+
+    for (c = 0; c < num_ctrls; ++c)
+        libxl_device_vscsictrl_dispose(ctrls + c);
+    free(ctrls);
+
+out:
+    GC_FREE;
+    return rc;
+}
+
+int libxl_device_vscsidev_remove(libxl_ctx *ctx, uint32_t domid,
+                                 libxl_device_vscsidev *vscsidev,
+                                 const libxl_asyncop_how *ao_how)
+{
+    GC_INIT(ctx);
+    libxl_device_vscsictrl *vc, *ctrls = NULL;
+    libxl_device_vscsidev *vd;
+    int c, d, rc, num_ctrls = 0;
+    int found = 0, idx;
+    int head, tail, i;
+
+    rc = vscsi_collect_ctrls(gc, domid, &ctrls, &num_ctrls);
+    if (rc != 0) goto out;
+
+
+    for (c = 0; c < num_ctrls; ++c) {
+        vc = ctrls + c;
+
+        for (d = 0; d < vc->num_vscsidevs; d++) {
+            vd = vc->vscsidevs + d;
+            if (vd->vdev.hst == vscsidev->vdev.hst &&
+                vd->vdev.chn == vscsidev->vdev.chn &&
+                vd->vdev.tgt == vscsidev->vdev.tgt &&
+                vd->vdev.lun == vscsidev->vdev.lun) {
+                found = 1;
+                idx = d;
+                break;
+            }
+        }
+
+        if (found) {
+            if (vc->num_vscsidevs > 1) {
+                /* Prepare vscsictrl, leave only desired vscsidev */
+                head = idx;
+                tail = vc->num_vscsidevs - idx - 1;
+                for (i = 0; i < head; i++)
+                    libxl_device_vscsictrl_remove_vscsidev(ctx, vc, 0);
+                for (i = 0; i < tail; i++)
+                    libxl_device_vscsictrl_remove_vscsidev(ctx, vc, 1);
+
+                /* Remove single vscsidev connected to this vscsictrl */
+                rc = vscsidev_remove(ctx, domid, vc, ao_how);
+            } else {
+                /* Wipe entire vscsictrl */;
+                rc = vscsictrl_remove(ctx, domid, vc, ao_how, 0);
+            }
+            break;
+        }
+    }
+
+    for (c = 0; c < num_ctrls; ++c)
+        libxl_device_vscsictrl_dispose(ctrls + c);
+    free(ctrls);
+
+    if (!found)
+        rc = ERROR_NOTFOUND;
+
+out:
+    GC_FREE;
+    return rc;
+}
+
+void libxl_device_vscsictrl_append_vscsidev(libxl_ctx *ctx,
+                                            libxl_device_vscsictrl *ctrl,
+                                            libxl_device_vscsidev *dev)
+{
+    GC_INIT(ctx);
+    ctrl->vscsidevs = libxl__realloc(NOGC, ctrl->vscsidevs, sizeof(*dev) * (ctrl->num_vscsidevs + 1));
+    libxl_device_vscsidev_init(ctrl->vscsidevs + ctrl->num_vscsidevs);
+    libxl_device_vscsidev_copy(CTX, ctrl->vscsidevs + ctrl->num_vscsidevs, dev);
+    ctrl->num_vscsidevs++;
+    GC_FREE;
+}
+
+void libxl_device_vscsictrl_remove_vscsidev(libxl_ctx *ctx,
+                                            libxl_device_vscsictrl *ctrl,
+                                            unsigned int idx)
+{
+    GC_INIT(ctx);
+    if (idx >= ctrl->num_vscsidevs)
+        return;
+    libxl_device_vscsidev_dispose(&ctrl->vscsidevs[idx]);
+    if (ctrl->num_vscsidevs > idx + 1)
+        memmove(&ctrl->vscsidevs[idx],
+                &ctrl->vscsidevs[idx + 1],
+                (ctrl->num_vscsidevs - idx - 1) * sizeof(*ctrl->vscsidevs));
+    ctrl->vscsidevs = libxl__realloc(NOGC, ctrl->vscsidevs, sizeof(*ctrl->vscsidevs) * (ctrl->num_vscsidevs - 1));
+    ctrl->num_vscsidevs--;
+    GC_FREE;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
Index: xen-4.7.0-testing/tools/libxl/libxlu_vscsi.c
===================================================================
--- /dev/null
+++ xen-4.7.0-testing/tools/libxl/libxlu_vscsi.c
@@ -0,0 +1,667 @@
+/*
+ * libxlu_vscsi.c - xl configuration file parsing: setup and helper functions
+ *
+ * Copyright (C) 2016      SUSE Linux GmbH
+ * Author Olaf Hering <olaf@aepfle.de>
+ * Author Ondřej Holeček <aaannz@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; version 2.1 only. with the special
+ * exception on linking described in file LICENSE.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ */
+#include "libxl_osdeps.h" /* must come before any other headers */
+#include <unistd.h>
+#include <ctype.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include "libxlu_internal.h"
+
+#ifdef __linux__
+#define LOG(_c, _x, _a...) \
+        if((_c) && (_c)->report) fprintf((_c)->report, "%s(%u): " _x "\n", __func__, __LINE__, ##_a)
+
+#define XLU_SYSFS_TARGET_PVSCSI "/sys/kernel/config/target/xen-pvscsi"
+#define XLU_WWN_LEN 16
+struct xlu__vscsi_target {
+    XLU_Config *cfg;
+    libxl_vscsi_hctl *pdev_hctl;
+    libxl_vscsi_pdev *pdev;
+    char path[PATH_MAX];
+    char udev_path[PATH_MAX];
+    char wwn[XLU_WWN_LEN + 1];
+    unsigned long long lun;
+};
+
+static int xlu__vscsi_parse_hctl(char *str, libxl_vscsi_hctl *hctl)
+{
+    unsigned int hst, chn, tgt;
+    unsigned long long lun;
+
+    if (sscanf(str, "%u:%u:%u:%llu", &hst, &chn, &tgt, &lun) != 4)
+        return ERROR_INVAL;
+
+    hctl->hst = hst;
+    hctl->chn = chn;
+    hctl->tgt = tgt;
+    hctl->lun = lun;
+    return 0;
+}
+
+static char *xlu__vscsi_trim_string(char *s)
+{
+    size_t len;
+
+    while (isspace(*s))
+        s++;
+    len = strlen(s);
+    while (len-- > 1 && isspace(s[len]))
+        s[len] = '\0';
+    return s;
+}
+
+
+static int xlu__vscsi_parse_dev(XLU_Config *cfg, char *pdev, libxl_vscsi_hctl *hctl)
+{
+    struct stat dentry;
+    char *sysfs = NULL;
+    const char *type;
+    int rc, found = 0;
+    DIR *dirp;
+    struct dirent *de;
+
+    /* stat pdev to get device's sysfs entry */
+    if (stat (pdev, &dentry) < 0) {
+        LOG(cfg, "%s, device node not found", pdev);
+        rc = ERROR_INVAL;
+        goto out;
+    }
+
+    if (S_ISBLK (dentry.st_mode)) {
+        type = "block";
+    } else if (S_ISCHR (dentry.st_mode)) {
+        type = "char";
+    } else {
+        LOG(cfg, "%s, device node not a block or char device", pdev);
+        rc = ERROR_INVAL;
+        goto out;
+    }
+
+    /* /sys/dev/type/major:minor symlink added in 2.6.27 */
+    if (asprintf(&sysfs, "/sys/dev/%s/%u:%u/device/scsi_device", type,
+                 major(dentry.st_rdev), minor(dentry.st_rdev)) < 0) {
+        sysfs = NULL;
+        rc = ERROR_NOMEM;
+        goto out;
+    }
+
+    dirp = opendir(sysfs);
+    if (!dirp) {
+        LOG(cfg, "%s, no major:minor link in sysfs", pdev);
+        rc = ERROR_INVAL;
+        goto out;
+    }
+
+    while ((de = readdir(dirp))) {
+        if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, ".."))
+            continue;
+
+        if (xlu__vscsi_parse_hctl(de->d_name, hctl))
+            continue;
+
+        found = 1;
+        break;
+    }
+    closedir(dirp);
+
+    if (!found) {
+        LOG(cfg, "%s, no h:c:t:l link in sysfs", pdev);
+        rc = ERROR_INVAL;
+        goto out;
+    }
+
+    rc = 0;
+out:
+    free(sysfs);
+    return rc;
+}
+
+static bool xlu__vscsi_compare_hctl(libxl_vscsi_hctl *a, libxl_vscsi_hctl *b)
+{
+    if (a->hst == b->hst &&
+        a->chn == b->chn &&
+        a->tgt == b->tgt &&
+        a->lun == b->lun)
+        return true;
+    return false;
+}
+
+/* Finally at
+ * /sys/kernel/config/target/xen-pvscsi/naa.<wwn>/tpgt_1/lun/lun_0/<X>/udev_path
+ */
+static bool xlu__vscsi_compare_udev(struct xlu__vscsi_target *tgt)
+{
+    bool ret;
+    int fd;
+    ssize_t read_sz;
+    libxl_vscsi_hctl udev_hctl;
+
+    libxl_vscsi_hctl_init(&udev_hctl);
+
+    fd = open(tgt->path, O_RDONLY);
+    if (fd < 0){
+        ret = false;
+        goto out;
+    }
+    read_sz = read(fd, &tgt->udev_path, sizeof(tgt->udev_path) - 1);
+    close(fd);
+
+    if (read_sz <= 0 || read_sz > sizeof(tgt->udev_path) - 1) {
+        ret = false;
+        goto out;
+    }
+    tgt->udev_path[read_sz] = '\0';
+    read_sz--;
+    if (tgt->udev_path[read_sz] == '\n')
+        tgt->udev_path[read_sz] = '\0';
+
+    if (xlu__vscsi_parse_dev(tgt->cfg, tgt->udev_path, &udev_hctl)) {
+        ret = false;
+        goto out;
+    }
+    ret = xlu__vscsi_compare_hctl(tgt->pdev_hctl, &udev_hctl);
+
+out:
+    libxl_vscsi_hctl_dispose(&udev_hctl);
+    return ret;
+}
+
+/* /sys/kernel/config/target/xen-pvscsi/naa.<wwn>/tpgt_1/lun/lun_0/<X>/udev_path */
+static bool xlu__vscsi_walk_dir_lun(struct xlu__vscsi_target *tgt)
+{
+    bool found;
+    DIR *dirp;
+    struct dirent *de;
+    size_t path_len = strlen(tgt->path);
+    char *subdir = &tgt->path[path_len];
+
+    dirp = opendir(tgt->path);
+    if (!dirp)
+        return false;
+
+    found = false;
+    while ((de = readdir(dirp))) {
+        if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, ".."))
+            continue;
+
+        snprintf(subdir, sizeof(tgt->path) - path_len, "/%s/udev_path", de->d_name);
+
+        found = xlu__vscsi_compare_udev(tgt);
+        if (found)
+            break;
+
+        *subdir = '\0';
+    }
+    closedir(dirp);
+    return found;
+}
+
+/* /sys/kernel/config/target/xen-pvscsi/naa.<wwn>/tpgt_1/lun/lun_0 */
+static bool xlu__vscsi_walk_dir_luns(struct xlu__vscsi_target *tgt)
+{
+    bool found;
+    DIR *dirp;
+    struct dirent *de;
+    size_t path_len = strlen(tgt->path);
+    char *subdir = &tgt->path[path_len];
+
+    dirp = opendir(tgt->path);
+    if (!dirp)
+        return false;
+
+    found = false;
+    while ((de = readdir(dirp))) {
+        if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, ".."))
+            continue;
+
+        if (sscanf(de->d_name, "lun_%llu", &tgt->lun) != 1)
+            continue;
+
+
+        snprintf(subdir, sizeof(tgt->path) - path_len, "/%s", de->d_name);
+
+        found = xlu__vscsi_walk_dir_lun(tgt);
+        if (found)
+            break;
+
+        *subdir = '\0';
+    }
+    closedir(dirp);
+    return found;
+}
+
+/* /sys/kernel/config/target/xen-pvscsi/naa.<wwn>/tpgt_1 */
+static bool xlu__vscsi_walk_dir_naa(struct xlu__vscsi_target *tgt)
+{
+    bool found;
+    DIR *dirp;
+    struct dirent *de;
+    size_t path_len = strlen(tgt->path);
+    char *subdir = &tgt->path[path_len];
+    unsigned int tpgt;
+
+    dirp = opendir(tgt->path);
+    if (!dirp)
+        return false;
+
+    found = false;
+    while ((de = readdir(dirp))) {
+        if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, ".."))
+            continue;
+
+        if (sscanf(de->d_name, "tpgt_%u", &tpgt) != 1)
+            continue;
+
+        snprintf(subdir, sizeof(tgt->path) - path_len, "/%s/lun", de->d_name);
+
+        found = xlu__vscsi_walk_dir_luns(tgt);
+        if (found)
+            break;
+
+        *subdir = '\0';
+    }
+    closedir(dirp);
+    return found;
+}
+
+/* /sys/kernel/config/target/xen-pvscsi/naa.<wwn> */
+static bool xlu__vscsi_find_target_wwn(struct xlu__vscsi_target *tgt)
+{
+    bool found;
+    DIR *dirp;
+    struct dirent *de;
+    size_t path_len = strlen(tgt->path);
+    char *subdir = &tgt->path[path_len];
+
+    dirp = opendir(tgt->path);
+    if (!dirp)
+        return false;
+
+    found = false;
+    while ((de = readdir(dirp))) {
+        if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, ".."))
+            continue;
+
+        if (sscanf(de->d_name, "naa.%16[0-9a-fA-F]", tgt->wwn) != 1)
+            continue;
+
+        snprintf(subdir, sizeof(tgt->path) - path_len, "/%s", de->d_name);
+
+        found = xlu__vscsi_walk_dir_naa(tgt);
+        if (found)
+            break;
+
+        *subdir = '\0';
+    }
+    closedir(dirp);
+    return found;
+}
+
+/*
+ * Convert pdev from config string into pdev property for backend,
+ * which is either h:c:t:l for xenlinux or naa.wwn:lun for pvops
+ */
+static int xlu__vscsi_dev_to_pdev(XLU_Config *cfg, libxl_ctx *ctx, char *str,
+                                  libxl_vscsi_hctl *pdev_hctl,
+                                  libxl_vscsi_pdev *pdev)
+{
+    int rc = ERROR_INVAL;
+    struct xlu__vscsi_target *tgt;
+    static const char xen_pvscsi[] = XLU_SYSFS_TARGET_PVSCSI;
+
+    /* First get hctl representation of config item */
+    if (xlu__vscsi_parse_dev(cfg, str, pdev_hctl))
+        goto out;
+
+    /* Check if a SCSI target item exists for the config item */
+    if (access(xen_pvscsi, F_OK) == 0) {
+        tgt = calloc(1, sizeof(*tgt));
+        if (!tgt) {
+            rc = ERROR_NOMEM;
+            goto out;
+        }
+        tgt->cfg = cfg;
+        tgt->pdev_hctl = pdev_hctl;
+        tgt->pdev = pdev;
+        snprintf(tgt->path, sizeof(tgt->path), "%s", xen_pvscsi);
+        if (xlu__vscsi_find_target_wwn(tgt) == true) {
+            LOG(cfg, "'%s' maps to '%s(%s)'", str, tgt->path, tgt->udev_path);
+            libxl_vscsi_pdev_init_type(pdev, LIBXL_VSCSI_PDEV_TYPE_WWN);
+            if (asprintf(&pdev->u.wwn.m, "naa.%s:%llu", tgt->wwn, tgt->lun) < 0) {
+                rc = ERROR_NOMEM;
+                goto out;
+            }
+        }
+        free(tgt);
+    } else {
+        /* Assume xenlinux backend */
+        libxl_vscsi_pdev_init_type(pdev, LIBXL_VSCSI_PDEV_TYPE_HCTL);
+        libxl_vscsi_hctl_copy(ctx, &pdev->u.hctl.m, pdev_hctl);
+    }
+    rc = 0;
+
+out:
+    return rc;
+}
+
+/* WWN as understood by pvops */
+static int xlu__vscsi_wwn_to_pdev(XLU_Config *cfg, char *str, libxl_vscsi_pdev *pdev)
+{
+    int rc = ERROR_INVAL;
+    unsigned long long lun;
+    char wwn[XLU_WWN_LEN + 1];
+
+    memset(wwn, 0, sizeof(wwn));
+    if (sscanf(str, "naa.%16[0-9a-fA-F]:%llu", wwn, &lun) == 2) {
+        libxl_vscsi_pdev_init_type(pdev, LIBXL_VSCSI_PDEV_TYPE_WWN);
+        pdev->u.wwn.m = strdup(str);
+        rc = pdev->u.wwn.m ? 0 : ERROR_NOMEM;
+    }
+    return rc;
+}
+
+static int xlu__vscsi_parse_pdev(XLU_Config *cfg, libxl_ctx *ctx, char *str,
+                                 libxl_vscsi_pdev *pdev)
+{
+    int rc = ERROR_INVAL;
+    libxl_vscsi_hctl pdev_hctl;
+
+    libxl_vscsi_hctl_init(&pdev_hctl);
+    if (strncmp(str, "/dev/", 5) == 0) {
+        rc = xlu__vscsi_dev_to_pdev(cfg, ctx, str, &pdev_hctl, pdev);
+    } else if (strncmp(str, "naa.", 4) == 0) {
+        rc = xlu__vscsi_wwn_to_pdev(cfg, str, pdev);
+    } else if (xlu__vscsi_parse_hctl(str, &pdev_hctl) == 0) {
+        /* Either xenlinux, or pvops with properly configured alias in sysfs */
+        libxl_vscsi_pdev_init_type(pdev, LIBXL_VSCSI_PDEV_TYPE_HCTL);
+        libxl_vscsi_hctl_copy(ctx, &pdev->u.hctl.m, &pdev_hctl);
+        rc = 0;
+    }
+
+    if (rc == 0) {
+            pdev->p_devname = strdup(str);
+            if (!pdev->p_devname)
+                rc = ERROR_NOMEM;
+    }
+
+    libxl_vscsi_hctl_dispose(&pdev_hctl);
+    return rc;
+}
+
+int xlu_vscsi_parse(XLU_Config *cfg, libxl_ctx *ctx, const char *str,
+                    libxl_device_vscsictrl *new_ctrl,
+                    libxl_device_vscsidev *new_dev)
+{
+    int rc;
+    char *tmp, *pdev, *vdev, *fhost;
+
+    tmp = strdup(str);
+    if (!tmp) {
+        rc = ERROR_NOMEM;
+        goto out;
+    }
+
+    pdev = strtok(tmp, ",");
+    vdev = strtok(NULL, ",");
+    fhost = strtok(NULL, ",");
+    if (!(pdev && vdev)) {
+        LOG(cfg, "invalid devspec: '%s'\n", str);
+        rc = ERROR_INVAL;
+        goto out;
+    }
+
+    pdev = xlu__vscsi_trim_string(pdev);
+    vdev = xlu__vscsi_trim_string(vdev);
+
+    rc = xlu__vscsi_parse_pdev(cfg, ctx, pdev, &new_dev->pdev);
+    if (rc) {
+        LOG(cfg, "failed to parse %s, rc == %d", pdev, rc);
+        goto out;
+    }
+
+    if (xlu__vscsi_parse_hctl(vdev, &new_dev->vdev)) {
+        LOG(cfg, "invalid '%s', expecting hst:chn:tgt:lun", vdev);
+        rc = ERROR_INVAL;
+        goto out;
+    }
+
+    new_ctrl->idx = new_dev->vdev.hst;
+
+    if (fhost) {
+        fhost = xlu__vscsi_trim_string(fhost);
+        if (strcmp(fhost, "feature-host") == 0) {
+            libxl_defbool_set(&new_ctrl->scsi_raw_cmds, true);
+        } else {
+            LOG(cfg, "invalid option '%s', expecting %s", fhost, "feature-host");
+            rc = ERROR_INVAL;
+            goto out;
+        }
+    } else
+        libxl_defbool_set(&new_ctrl->scsi_raw_cmds, false);
+    rc = 0;
+
+out:
+    free(tmp);
+    return rc;
+}
+
+int xlu_vscsi_get_ctrl(XLU_Config *cfg, libxl_ctx *ctx, uint32_t domid,
+                       const char *str,
+                       libxl_device_vscsictrl *ctrl,
+                       libxl_device_vscsidev *dev,
+                       libxl_device_vscsictrl *existing,
+                       bool *found_existing)
+{
+    libxl_device_vscsictrl *vscsictrls = NULL, *tmp;
+    int rc, found_ctrl = -1, i;
+    int num_ctrls;
+
+
+    rc = xlu_vscsi_parse(cfg, ctx, str, ctrl, dev);
+    if (rc)
+        goto out;
+
+    /* Look for existing vscsictrl for given domain */
+    vscsictrls = libxl_device_vscsictrl_list(ctx, domid, &num_ctrls);
+    if (vscsictrls) {
+        for (i = 0; i < num_ctrls; ++i) {
+            if (vscsictrls[i].idx == dev->vdev.hst) {
+                found_ctrl = i;
+                break;
+            }
+        }
+    }
+
+    if (found_ctrl == -1) {
+        *found_existing = false;
+    } else {
+        *found_existing = true;
+        tmp = vscsictrls + found_ctrl;
+
+        /* Check if the vdev address is already taken */
+        for (i = 0; i < tmp->num_vscsidevs; ++i) {
+            if (tmp->vscsidevs[i].vdev.chn == dev->vdev.chn &&
+                tmp->vscsidevs[i].vdev.tgt == dev->vdev.tgt &&
+                tmp->vscsidevs[i].vdev.lun == dev->vdev.lun) {
+                unsigned long long lun = dev->vdev.lun;
+                LOG(cfg, "vdev '%u:%u:%u:%llu' is already used.\n",
+                    dev->vdev.hst, dev->vdev.chn, dev->vdev.tgt, lun);
+                rc = ERROR_INVAL;
+                goto out;
+            }
+        }
+
+        if (libxl_defbool_val(ctrl->scsi_raw_cmds) !=
+            libxl_defbool_val(tmp->scsi_raw_cmds)) {
+            LOG(cfg, "different feature-host setting: "
+                      "existing ctrl has it %s, new ctrl has it %s\n",
+                libxl_defbool_val(ctrl->scsi_raw_cmds) ? "set" : "unset",
+                libxl_defbool_val(tmp->scsi_raw_cmds) ? "set" : "unset");
+            rc = ERROR_INVAL;
+            goto out;
+        }
+
+        libxl_device_vscsictrl_copy(ctx, existing, tmp);
+    }
+
+    rc = 0;
+
+out:
+    if (vscsictrls) {
+        for (i = 0; i < num_ctrls; ++i)
+            libxl_device_vscsictrl_dispose(vscsictrls + i);
+        free(vscsictrls);
+    }
+    return rc;
+}
+
+int xlu_vscsi_detach(XLU_Config *cfg, libxl_ctx *ctx, uint32_t domid, char *str)
+{
+    libxl_device_vscsidev dev = { };
+    libxl_device_vscsictrl ctrl = { };
+    int rc;
+    char *tmp = NULL;
+
+    libxl_device_vscsictrl_init(&ctrl);
+    libxl_device_vscsidev_init(&dev);
+
+    /* Create a dummy cfg */
+    if (asprintf(&tmp, "0:0:0:0,%s", str) < 0) {
+        LOG(cfg, "asprintf failed while removing %s from domid %u", str, domid);
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    rc = xlu_vscsi_parse(cfg, ctx, tmp, &ctrl, &dev);
+    if (rc) goto out;
+
+    rc = libxl_device_vscsidev_remove(ctx, domid, &dev, NULL);
+    switch (rc) {
+    case ERROR_NOTFOUND:
+        LOG(cfg, "detach failed: %s does not exist in domid %u", str, domid);
+        break;
+    default:
+        break;
+    }
+
+out:
+    free(tmp);
+    libxl_device_vscsidev_dispose(&dev);
+    libxl_device_vscsictrl_dispose(&ctrl);
+    return rc;
+}
+
+int xlu_vscsi_config_add(XLU_Config *cfg,
+                         libxl_ctx *ctx,
+                         const char *str,
+                         int *num_vscsis,
+                         libxl_device_vscsictrl **vscsis)
+{
+    int rc, i;
+    libxl_device_vscsidev dev = { };
+    libxl_device_vscsictrl *tmp_ctrl, ctrl = { };
+    bool ctrl_found = false;
+
+    /*
+     * #1: parse the devspec and place it in temporary ctrl+dev part
+     * #2: find existing vscsictrl with number vdev.hst
+     *     if found, append the vscsidev to this vscsictrl
+     * #3: otherwise, create new vscsictrl and append vscsidev
+     * Note: vdev.hst does not represent the index named "num_vscsis",
+     *       it is a private index used just in the config file
+     */
+    libxl_device_vscsictrl_init(&ctrl);
+    libxl_device_vscsidev_init(&dev);
+
+    rc = xlu_vscsi_parse(cfg, ctx, str, &ctrl, &dev);
+    if (rc)
+        goto out;
+
+    if (*num_vscsis) {
+        for (i = 0; i < *num_vscsis; i++) {
+            tmp_ctrl = *vscsis + i;
+            if (tmp_ctrl->idx == dev.vdev.hst) {
+                libxl_device_vscsictrl_append_vscsidev(ctx, tmp_ctrl, &dev);
+                ctrl_found = true;
+                break;
+	           }
+        }
+    }
+
+    if (!ctrl_found || !*num_vscsis) {
+        tmp_ctrl = realloc(*vscsis, sizeof(ctrl) * (*num_vscsis + 1));
+        if (!tmp_ctrl) {
+            LOG(cfg, "realloc #%d failed", *num_vscsis + 1);
+            rc = ERROR_NOMEM;
+            goto out;
+        }
+        *vscsis = tmp_ctrl;
+        tmp_ctrl = *vscsis + *num_vscsis;
+        libxl_device_vscsictrl_init(tmp_ctrl);
+
+        libxl_device_vscsictrl_copy(ctx, tmp_ctrl, &ctrl);
+
+        libxl_device_vscsictrl_append_vscsidev(ctx, tmp_ctrl, &dev);
+
+        (*num_vscsis)++;
+    }
+
+    rc = 0;
+out:
+    libxl_device_vscsidev_dispose(&dev);
+    libxl_device_vscsictrl_dispose(&ctrl);
+    return rc;
+}
+#else /* ! __linux__ */
+int xlu_vscsi_get_ctrl(XLU_Config *cfg, libxl_ctx *ctx, uint32_t domid,
+                       const char *str,
+                       libxl_device_vscsictrl *ctrl,
+                       libxl_device_vscsidev *dev,
+                       libxl_device_vscsictrl *existing,
+                       bool *found_existing)
+{
+    return ERROR_INVAL;
+}
+
+int xlu_vscsi_parse(XLU_Config *cfg,
+                    libxl_ctx *ctx,
+                    const char *str,
+                    libxl_device_vscsictrl *new_ctrl,
+                    libxl_device_vscsidev *new_dev)
+{
+    return ERROR_INVAL;
+}
+
+int xlu_vscsi_detach(XLU_Config *cfg,
+                     libxl_ctx *ctx,
+                     uint32_t domid,
+                     char *str)
+{
+    return ERROR_INVAL;
+}
+
+int xlu_vscsi_config_add(XLU_Config *cfg,
+                         libxl_ctx *ctx,
+                         const char *str,
+                         int *num_vscsis,
+                         libxl_device_vscsictrl **vscsis)
+{
+    return ERROR_INVAL;
+}
+#endif
Index: xen-4.7.0-testing/tools/libxl/libxlutil.h
===================================================================
--- xen-4.7.0-testing.orig/tools/libxl/libxlutil.h
+++ xen-4.7.0-testing/tools/libxl/libxlutil.h
@@ -118,6 +118,25 @@ int xlu_rdm_parse(XLU_Config *cfg, libxl
 int xlu_vif_parse_rate(XLU_Config *cfg, const char *rate,
                        libxl_device_nic *nic);
 
+/* Fill ctrl/dev with device described in str (pdev,vdev[,options]) */
+int xlu_vscsi_get_ctrl(XLU_Config *cfg, libxl_ctx *ctx, uint32_t domid,
+                       const char *str,
+                       libxl_device_vscsictrl *ctrl,
+                       libxl_device_vscsidev *dev,
+                       libxl_device_vscsictrl *existing,
+                       bool *found_existing);
+/* Parse config string and fill provided vscsi ctrl and vscsi device */
+int xlu_vscsi_parse(XLU_Config *cfg, libxl_ctx *ctx, const char *str,
+                    libxl_device_vscsictrl *new_ctrl,
+                    libxl_device_vscsidev *new_dev);
+/* Detach vscsi device described in config string (pdev,vdev[,options]) */
+int xlu_vscsi_detach(XLU_Config *cfg, libxl_ctx *ctx, uint32_t domid, char *str);
+/* Add vscsi device described in config string (pdev,vdev[,options]) to d_config */
+int xlu_vscsi_config_add(XLU_Config *cfg,
+                         libxl_ctx *ctx,
+                         const char *str,
+                         int *num_vscsis,
+                         libxl_device_vscsictrl **vscsis);
 #endif /* LIBXLUTIL_H */
 
 /*
Index: xen-4.7.0-testing/tools/libxl/xl.h
===================================================================
--- xen-4.7.0-testing.orig/tools/libxl/xl.h
+++ xen-4.7.0-testing/tools/libxl/xl.h
@@ -89,6 +89,9 @@ int main_channellist(int argc, char **ar
 int main_blockattach(int argc, char **argv);
 int main_blocklist(int argc, char **argv);
 int main_blockdetach(int argc, char **argv);
+int main_vscsiattach(int argc, char **argv);
+int main_vscsilist(int argc, char **argv);
+int main_vscsidetach(int argc, char **argv);
 int main_vtpmattach(int argc, char **argv);
 int main_vtpmlist(int argc, char **argv);
 int main_vtpmdetach(int argc, char **argv);
Index: xen-4.7.0-testing/tools/libxl/xl_cmdimpl.c
===================================================================
--- xen-4.7.0-testing.orig/tools/libxl/xl_cmdimpl.c
+++ xen-4.7.0-testing/tools/libxl/xl_cmdimpl.c
@@ -1325,7 +1325,7 @@ static void parse_config_data(const char
     long l, vcpus = 0;
     XLU_Config *config;
     XLU_ConfigList *cpus, *vbds, *nics, *pcis, *cvfbs, *cpuids, *vtpms,
-                   *usbctrls, *usbdevs;
+                   *usbctrls, *usbdevs, *vscsictrls;
     XLU_ConfigList *channels, *ioports, *irqs, *iomem, *viridian, *dtdevs;
     int num_ioports, num_irqs, num_iomem, num_cpus, num_viridian;
     int pci_power_mgmt = 0;
@@ -1855,6 +1855,17 @@ static void parse_config_data(const char
         }
     }
 
+    if (!xlu_cfg_get_list(config, "vscsi", &vscsictrls, 0, 0)) {
+        int num_vscsi_items = 0;
+        d_config->num_vscsictrls = 0;
+        d_config->vscsictrls = NULL;
+        while ((buf = xlu_cfg_get_listitem (vscsictrls, num_vscsi_items)) != NULL) {
+            if (xlu_vscsi_config_add(config, ctx, buf, &d_config->num_vscsictrls, &d_config->vscsictrls))
+                exit(1);
+            num_vscsi_items++;
+        }
+    }
+
     if (!xlu_cfg_get_list(config, "vtpm", &vtpms, 0, 0)) {
         d_config->num_vtpms = 0;
         d_config->vtpms = NULL;
@@ -7416,6 +7427,218 @@ int main_blockdetach(int argc, char **ar
     return rc;
 }
 
+int main_vscsiattach(int argc, char **argv)
+{
+    uint32_t domid;
+    int opt, rc;
+    XLU_Config *config = NULL;
+    libxl_device_vscsictrl ctrl, existing;
+    libxl_device_vscsidev dev;
+    bool found_existing = false;
+    char *str = NULL, *feat_buf = NULL;
+    char *json;
+
+    SWITCH_FOREACH_OPT(opt, "", NULL, "scsi-attach", 1) {
+        /* No options */
+    }
+
+    if (argc < 4 || argc > 5) {
+        help("scsi-attach");
+        return 1;
+    }
+
+    if (libxl_domain_qualifier_to_domid(ctx, argv[optind], &domid) < 0) {
+        fprintf(stderr, "%s is an invalid domain identifier\n", argv[optind]);
+        return 1;
+    }
+
+    optind++;
+
+    if (argc == 5) {
+        if (asprintf(&feat_buf, ",%s", argv[4]) < 0) {
+            perror("asprintf");
+            return 1;
+        }
+    }
+
+    if (asprintf(&str, "%s,%s%s", argv[2], argv[3], feat_buf ?: "") < 0) {
+        perror("asprintf");
+        rc = 1;
+        goto out;;
+    }
+
+    libxl_device_vscsictrl_init(&existing);
+    libxl_device_vscsictrl_init(&ctrl);
+    libxl_device_vscsidev_init(&dev);
+
+    config = xlu_cfg_init(stderr, "command line");
+    if (!config) {
+        fprintf(stderr, "Failed to allocate for configuration\n");
+        rc = 1;
+        goto out;
+    }
+
+    /* Parse config string and store result */
+    rc = xlu_vscsi_get_ctrl(config, ctx, domid, str, &ctrl, &dev, &existing, &found_existing);
+    if (rc < 0)
+        goto out;
+
+    if (dryrun_only) {
+        libxl_device_vscsictrl *tmp = found_existing ? &existing : &ctrl;
+        libxl_device_vscsictrl_append_vscsidev(ctx, tmp , &dev);
+        json = libxl_device_vscsictrl_to_json(ctx, tmp);
+        printf("vscsi: %s\n", json);
+        free(json);
+        if (ferror(stdout) || fflush(stdout)) { perror("stdout"); exit(-1); }
+        rc = 0;
+        goto out;
+    }
+
+    /* Finally add the device */
+    if (found_existing) {
+        if (libxl_device_vscsidev_add(ctx, domid, &dev, NULL)) {
+            fprintf(stderr, "libxl_device_vscsidev_add failed\n");
+            rc = 1;
+            goto out;
+        }
+    } else {
+        libxl_device_vscsictrl_append_vscsidev(ctx, &ctrl, &dev);
+        if (libxl_device_vscsictrl_add(ctx, domid, &ctrl, NULL)) {
+            fprintf(stderr, "libxl_device_vscsictrl_add failed.\n");
+            rc = 1;
+            goto out;
+        }
+    }
+
+    rc = 0;
+out:
+    if (config)
+        xlu_cfg_destroy(config);
+    libxl_device_vscsictrl_dispose(&existing);
+    libxl_device_vscsictrl_dispose(&ctrl);
+    libxl_device_vscsidev_dispose(&dev);
+    free(str);
+    free(feat_buf);
+    return rc;
+}
+
+int main_vscsilist(int argc, char **argv)
+{
+    int opt;
+    uint32_t domid;
+    libxl_device_vscsictrl *vscsictrls;
+    libxl_vscsiinfo vscsiinfo;
+    int num_ctrls, h, d;
+
+    SWITCH_FOREACH_OPT(opt, "", NULL, "scsi-list", 1) {
+        /* No options */
+    }
+    if (argc < 2) {
+        help("scsi-list");
+        return 1;
+    }
+
+    /*      Idx  BE  state ctrl p_hst v_hst state */
+    printf("%-3s %-3s %-5s %-5s %-10s %-10s %-5s\n",
+           "Idx", "BE", "state", "ctrl", "phy-hctl", "vir-hctl", "devstate");
+    for (argv += optind, argc -= optind; argc > 0; --argc, ++argv) {
+        if (libxl_domain_qualifier_to_domid(ctx, *argv, &domid) < 0) {
+            fprintf(stderr, "%s is an invalid domain identifier\n", *argv);
+            continue;
+        }
+        vscsictrls = libxl_device_vscsictrl_list(ctx, domid, &num_ctrls);
+        if (!vscsictrls)
+            continue;
+
+        for (h = 0; h < num_ctrls; ++h) {
+            for (d = 0; d < vscsictrls[h].num_vscsidevs; d++) {
+                if (!libxl_device_vscsictrl_getinfo(ctx, domid, &vscsictrls[h],
+                                                &vscsictrls[h].vscsidevs[d],
+                                                &vscsiinfo)) {
+                    char pdev[64], vdev[64];
+                    unsigned long long lun;
+                    switch (vscsiinfo.pdev.type) {
+                    case LIBXL_VSCSI_PDEV_TYPE_HCTL:
+                        lun = vscsiinfo.pdev.u.hctl.m.lun;
+                        snprintf(pdev, sizeof(pdev), "%u:%u:%u:%llu",
+                                 vscsiinfo.pdev.u.hctl.m.hst,
+                                 vscsiinfo.pdev.u.hctl.m.chn,
+                                 vscsiinfo.pdev.u.hctl.m.tgt,
+                                 lun);
+                        break;
+                    case LIBXL_VSCSI_PDEV_TYPE_WWN:
+                        snprintf(pdev, sizeof(pdev), "%s",
+                                 vscsiinfo.pdev.u.wwn.m);
+                        break;
+                    default:
+                        pdev[0] = '\0';
+                        break;
+                    }
+                    lun = vscsiinfo.vdev.lun;
+                    snprintf(vdev, sizeof(vdev), "%u:%u:%u:%llu",
+                             vscsiinfo.vdev.hst,
+                             vscsiinfo.vdev.chn,
+                             vscsiinfo.vdev.tgt,
+                             lun);
+                    /*      Idx  BE  state Sta */
+                    printf("%-3d %-3d %-5d %-5d %-10s %-10s %d\n",
+                           vscsiinfo.devid,
+                           vscsiinfo.backend_id,
+                           vscsiinfo.vscsictrl_state,
+                           vscsiinfo.backend_id,
+                           pdev, vdev,
+                           vscsiinfo.vscsidev_state);
+
+                }
+                libxl_vscsiinfo_dispose(&vscsiinfo);
+            }
+            libxl_device_vscsictrl_dispose(&vscsictrls[h]);
+        }
+        free(vscsictrls);
+
+    }
+
+    return 0;
+}
+
+int main_vscsidetach(int argc, char **argv)
+{
+    int opt;
+    char *dom = argv[1], *str = argv[2];
+    uint32_t domid;
+    XLU_Config *config = NULL;
+    int rc = 0;
+
+    SWITCH_FOREACH_OPT(opt, "", NULL, "scsi-detach", 1) {
+        /* No options */
+    }
+
+    if (argc < 3) {
+        help("scsi-detach");
+        return 1;
+    }
+
+    if (libxl_domain_qualifier_to_domid(ctx, dom, &domid) < 0) {
+        fprintf(stderr, "%s is an invalid domain identifier\n", dom);
+        return 1;
+    }
+
+    config = xlu_cfg_init(stderr, "command line");
+    if (!config) {
+        fprintf(stderr, "Failed to allocate for configuration\n");
+        goto out;
+    }
+
+    rc = xlu_vscsi_detach(config, ctx, domid, str);
+    if (rc)
+        fprintf(stderr, "scsi-detach %s %s failed: %d\n", dom, str, rc);
+
+out:
+    if (config)
+        xlu_cfg_destroy(config);
+    return !!rc;
+}
+
 int main_vtpmattach(int argc, char **argv)
 {
     int opt;
Index: xen-4.7.0-testing/tools/libxl/xl_cmdtable.c
===================================================================
--- xen-4.7.0-testing.orig/tools/libxl/xl_cmdtable.c
+++ xen-4.7.0-testing/tools/libxl/xl_cmdtable.c
@@ -354,6 +354,21 @@ struct cmd_spec cmd_table[] = {
       "Destroy a domain's virtual block device",
       "<Domain> <DevId>",
     },
+    { "scsi-attach",
+      &main_vscsiattach, 1, 1,
+      "Attach a dom0 SCSI device to a domain.",
+      "<Domain> <PhysDevice> <VirtDevice>",
+    },
+    { "scsi-list",
+      &main_vscsilist, 0, 0,
+      "List all dom0 SCSI devices currently attached to a domain.",
+      "<Domain(s)>",
+    },
+    { "scsi-detach",
+      &main_vscsidetach, 0, 1,
+      "Detach a specified SCSI device from a domain.",
+      "<Domain> <VirtDevice>",
+    },
     { "vtpm-attach",
       &main_vtpmattach, 1, 1,
       "Create a new virtual TPM device",