diff mbox

[v3,2/3] vus: Introduce vhost-user-scsi host device

Message ID 1482358659-4288-3-git-send-email-felipe@nutanix.com (mailing list archive)
State New, archived
Headers show

Commit Message

Felipe Franciosi Dec. 21, 2016, 10:17 p.m. UTC
This commit introduces a vhost-user device for SCSI. This is based
on the existing vhost-scsi implementation, but done over vhost-user
instead. It also uses a chardev to connect to the backend. Unlike
vhost-scsi (today), VMs using vhost-user-scsi can be live migrated.

To use it, one must configure Qemu with --enable-vhost-user-scsi and
start Qemu with a command line equivalent to:

qemu-system-x86_64 \
       -chardev socket,id=vus0,path=/tmp/vus.sock \
       -device vhost-user-scsi-pci,chardev=vus0,bus=pci.0,addr=...

A separate commit presents a sample application linked with libiscsi to
provide a backend for vhost-user-scsi.

Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
---
 configure                           |  10 ++
 hw/scsi/Makefile.objs               |   1 +
 hw/scsi/vhost-user-scsi.c           | 215 ++++++++++++++++++++++++++++++++++++
 hw/virtio/virtio-pci.c              |  58 ++++++++++
 hw/virtio/virtio-pci.h              |  15 +++
 include/hw/virtio/vhost-user-scsi.h |  35 ++++++
 include/hw/virtio/virtio-scsi.h     |   5 +
 7 files changed, 339 insertions(+)
 create mode 100644 hw/scsi/vhost-user-scsi.c
 create mode 100644 include/hw/virtio/vhost-user-scsi.h

Comments

Paolo Bonzini Jan. 2, 2017, 10:25 a.m. UTC | #1
On 21/12/2016 23:17, Felipe Franciosi wrote:
> To use it, one must configure Qemu with --enable-vhost-user-scsi and
> start Qemu with a command line equivalent to:
> 
> qemu-system-x86_64 \
>        -chardev socket,id=vus0,path=/tmp/vus.sock \
>        -device vhost-user-scsi-pci,chardev=vus0,bus=pci.0,addr=...
> 
> A separate commit presents a sample application linked with libiscsi to
> provide a backend for vhost-user-scsi.

Please place CONFIG_VHOST_USER_SCSI=$(CONFIG_POSIX) symbol in
default-configs/ (so that it is enabled by default on non-Windows hosts)
instead of having the configure option.  Otherwise, the patches look good!

Paolo
Felipe Franciosi Jan. 2, 2017, 6:07 p.m. UTC | #2
> On 2 Jan 2017, at 10:25, Paolo Bonzini <pbonzini@redhat.com> wrote:
> 
> 
> 
> On 21/12/2016 23:17, Felipe Franciosi wrote:
>> To use it, one must configure Qemu with --enable-vhost-user-scsi and
>> start Qemu with a command line equivalent to:
>> 
>> qemu-system-x86_64 \
>>       -chardev socket,id=vus0,path=/tmp/vus.sock \
>>       -device vhost-user-scsi-pci,chardev=vus0,bus=pci.0,addr=...
>> 
>> A separate commit presents a sample application linked with libiscsi to
>> provide a backend for vhost-user-scsi.
> 
> Please place CONFIG_VHOST_USER_SCSI=$(CONFIG_POSIX) symbol in
> default-configs/ (so that it is enabled by default on non-Windows hosts)
> instead of having the configure option.  Otherwise, the patches look good!

Thanks, will do that and send a v4.

Do you want any entries on MAINTAINERS for this code or are you happy to take care of it under hw/scsi/* ?

Felipe

> 
> Paolo
Paolo Bonzini Jan. 3, 2017, 9:32 a.m. UTC | #3
On 02/01/2017 19:07, Felipe Franciosi wrote:
> 
>> On 2 Jan 2017, at 10:25, Paolo Bonzini <pbonzini@redhat.com> wrote:
>>
>>
>>
>> On 21/12/2016 23:17, Felipe Franciosi wrote:
>>> To use it, one must configure Qemu with --enable-vhost-user-scsi and
>>> start Qemu with a command line equivalent to:
>>>
>>> qemu-system-x86_64 \
>>>       -chardev socket,id=vus0,path=/tmp/vus.sock \
>>>       -device vhost-user-scsi-pci,chardev=vus0,bus=pci.0,addr=...
>>>
>>> A separate commit presents a sample application linked with libiscsi to
>>> provide a backend for vhost-user-scsi.
>>
>> Please place CONFIG_VHOST_USER_SCSI=$(CONFIG_POSIX) symbol in
>> default-configs/ (so that it is enabled by default on non-Windows hosts)
>> instead of having the configure option.  Otherwise, the patches look good!
> 
> Thanks, will do that and send a v4.
> 
> Do you want any entries on MAINTAINERS for this code or are you happy to take care of it under hw/scsi/* ?

It's okay to have it under hw/scsi/*.

Paolo
Felipe Franciosi Jan. 13, 2017, 12:31 a.m. UTC | #4
Hi Paolo,

Thanks again for the review.
Just to clarify:

> On 2 Jan 2017, at 02:25, Paolo Bonzini <pbonzini@redhat.com> wrote:
> 
> 
> 
> On 21/12/2016 23:17, Felipe Franciosi wrote:
>> To use it, one must configure Qemu with --enable-vhost-user-scsi and
>> start Qemu with a command line equivalent to:
>> 
>> qemu-system-x86_64 \
>>       -chardev socket,id=vus0,path=/tmp/vus.sock \
>>       -device vhost-user-scsi-pci,chardev=vus0,bus=pci.0,addr=...
>> 
>> A separate commit presents a sample application linked with libiscsi to
>> provide a backend for vhost-user-scsi.
> 
> Please place CONFIG_VHOST_USER_SCSI=$(CONFIG_POSIX) symbol in
> default-configs/ (so that it is enabled by default on non-Windows hosts)
> instead of having the configure option.  Otherwise, the patches look good!

Which architectures would you like me to add this to? How about putting it in "pci.mak"?

And when you say "instead", do you mean on top of? I imagine having a --disable switch is at least desirable, so I'd rather not remove the commands from 'configure'.

Cheers,
Felipe

> 
> Paolo
Paolo Bonzini Jan. 16, 2017, 4:43 p.m. UTC | #5
On 13/01/2017 01:31, Felipe Franciosi wrote:
>> Please place CONFIG_VHOST_USER_SCSI=$(CONFIG_POSIX) symbol in
>> default-configs/ (so that it is enabled by default on non-Windows hosts)
>> instead of having the configure option.  Otherwise, the patches look good!
>
> Which architectures would you like me to add this to? How about putting it in "pci.mak"?

I think it should be in every configuration that includes virtio-scsi.

> And when you say "instead", do you mean on top of? I imagine having a --disable switch is at least desirable, so I'd rather not remove the commands from 'configure'.

No, I really meant "instead".  Even though the default-configs/
mechanisms is not very user-friendly, having two ways to do
configuration is messy.  Generally --disable is left for features that
require a third-party library.

Paolo
diff mbox

Patch

diff --git a/configure b/configure
index 3770d7c..dc73e5f 100755
--- a/configure
+++ b/configure
@@ -228,6 +228,7 @@  xfs=""
 
 vhost_net="no"
 vhost_scsi="no"
+vhost_user_scsi="no"
 vhost_vsock="no"
 kvm="no"
 colo="yes"
@@ -680,6 +681,7 @@  Haiku)
   kvm="yes"
   vhost_net="yes"
   vhost_scsi="yes"
+  vhost_user_scsi="yes"
   vhost_vsock="yes"
   QEMU_INCLUDES="-I\$(SRC_PATH)/linux-headers -I$(pwd)/linux-headers $QEMU_INCLUDES"
 ;;
@@ -1026,6 +1028,10 @@  for opt do
   ;;
   --enable-vhost-scsi) vhost_scsi="yes"
   ;;
+  --disable-vhost-user-scsi) vhost_user_scsi="no"
+  ;;
+  --enable-vhost-user-scsi) vhost_user_scsi="yes"
+  ;;
   --disable-vhost-vsock) vhost_vsock="no"
   ;;
   --enable-vhost-vsock) vhost_vsock="yes"
@@ -5061,6 +5067,7 @@  echo "posix_madvise     $posix_madvise"
 echo "libcap-ng support $cap_ng"
 echo "vhost-net support $vhost_net"
 echo "vhost-scsi support $vhost_scsi"
+echo "vhost-user-scsi support $vhost_user_scsi"
 echo "vhost-vsock support $vhost_vsock"
 echo "Trace backends    $trace_backends"
 if have_backend "simple"; then
@@ -5446,6 +5453,9 @@  fi
 if test "$vhost_scsi" = "yes" ; then
   echo "CONFIG_VHOST_SCSI=y" >> $config_host_mak
 fi
+if test "$vhost_user_scsi" = "yes" ; then
+  echo "CONFIG_VHOST_USER_SCSI=y" >> $config_host_mak
+fi
 if test "$vhost_net" = "yes" ; then
   echo "CONFIG_VHOST_NET_USED=y" >> $config_host_mak
 fi
diff --git a/hw/scsi/Makefile.objs b/hw/scsi/Makefile.objs
index 54d8754..b188f72 100644
--- a/hw/scsi/Makefile.objs
+++ b/hw/scsi/Makefile.objs
@@ -11,4 +11,5 @@  obj-$(CONFIG_PSERIES) += spapr_vscsi.o
 ifeq ($(CONFIG_VIRTIO),y)
 obj-y += virtio-scsi.o virtio-scsi-dataplane.o
 obj-$(CONFIG_VHOST_SCSI) += vhost-scsi-common.o vhost-scsi.o
+obj-$(CONFIG_VHOST_USER_SCSI) += vhost-scsi-common.o vhost-user-scsi.o
 endif
diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
new file mode 100644
index 0000000..ff81626
--- /dev/null
+++ b/hw/scsi/vhost-user-scsi.c
@@ -0,0 +1,215 @@ 
+/*
+ * vhost-user-scsi host device
+ *
+ * Copyright (c) 2016 Nutanix Inc. All rights reserved.
+ *
+ * Author:
+ *  Felipe Franciosi <felipe@nutanix.com>
+ *
+ * This work is largely based on the "vhost-scsi" implementation by:
+ *  Stefan Hajnoczi    <stefanha@linux.vnet.ibm.com>
+ *  Nicholas Bellinger <nab@risingtidesystems.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "migration/vmstate.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "qemu/typedefs.h"
+#include "qom/object.h"
+#include "hw/fw-path-provider.h"
+#include "hw/qdev-core.h"
+#include "hw/virtio/vhost.h"
+#include "hw/virtio/vhost-backend.h"
+#include "hw/virtio/vhost-user-scsi.h"
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/virtio-access.h"
+#include "sysemu/char.h"
+
+/* Features supported by the host application */
+static const int user_feature_bits[] = {
+    VIRTIO_F_NOTIFY_ON_EMPTY,
+    VIRTIO_RING_F_INDIRECT_DESC,
+    VIRTIO_RING_F_EVENT_IDX,
+    VIRTIO_SCSI_F_HOTPLUG,
+    VHOST_INVALID_FEATURE_BIT
+};
+
+static void vhost_user_scsi_set_status(VirtIODevice *vdev, uint8_t status)
+{
+    VHostUserSCSI *s = (VHostUserSCSI *)vdev;
+    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
+    bool start = (status & VIRTIO_CONFIG_S_DRIVER_OK) && vdev->vm_running;
+
+    if (vsc->dev.started == start) {
+        return;
+    }
+
+    if (start) {
+        int ret;
+
+        ret = vhost_scsi_common_start(vsc);
+        if (ret < 0) {
+            error_report("unable to start vhost-user-scsi: %s", strerror(-ret));
+            exit(1);
+        }
+    } else {
+        vhost_scsi_common_stop(vsc);
+    }
+}
+
+static void vhost_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
+{
+}
+
+static void vhost_user_scsi_save(QEMUFile *f, void *opaque)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
+    virtio_save(vdev, f);
+}
+
+static int vhost_user_scsi_load(QEMUFile *f, void *opaque, int version_id)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
+    return virtio_load(vdev, f, version_id);
+}
+
+static void vhost_user_scsi_realize(DeviceState *dev, Error **errp)
+{
+    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(dev);
+    VHostUserSCSI *s = VHOST_USER_SCSI(dev);
+    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
+    static int vhost_user_scsi_id;
+    Error *err = NULL;
+    int ret;
+
+    if (!vs->conf.chardev.chr) {
+        error_setg(errp, "vhost-user-scsi: missing chardev");
+        return;
+    }
+
+    virtio_scsi_common_realize(dev, &err, vhost_dummy_handle_output,
+                               vhost_dummy_handle_output,
+                               vhost_dummy_handle_output);
+    if (err != NULL) {
+        error_propagate(errp, err);
+        return;
+    }
+
+    vsc->dev.nvqs = 2 + vs->conf.num_queues;
+    vsc->dev.vqs = g_new(struct vhost_virtqueue, vsc->dev.nvqs);
+    vsc->dev.vq_index = 0;
+    vsc->dev.backend_features = 0;
+
+    ret = vhost_dev_init(&vsc->dev, (void *)&vs->conf.chardev,
+                         VHOST_BACKEND_TYPE_USER, 0);
+    if (ret < 0) {
+        error_setg(errp, "vhost-user-scsi: vhost initialization failed: %s",
+                   strerror(-ret));
+        return;
+    }
+
+    /* Channel and lun both are 0 for bootable vhost-user-scsi disk */
+    vsc->channel = 0;
+    vsc->lun = 0;
+    vsc->target = vs->conf.boot_tpgt;
+
+    register_savevm(dev, "vhost-user-scsi", vhost_user_scsi_id++, 1,
+                    vhost_user_scsi_save, vhost_user_scsi_load, s);
+}
+
+static void vhost_user_scsi_unrealize(DeviceState *dev, Error **errp)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VHostUserSCSI *s = VHOST_USER_SCSI(dev);
+    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
+
+    /* This will stop the vhost backend. */
+    vhost_user_scsi_set_status(vdev, 0);
+
+    vhost_dev_cleanup(&vsc->dev);
+    g_free(vsc->dev.vqs);
+
+    virtio_scsi_common_unrealize(dev, errp);
+}
+
+static uint64_t vhost_user_scsi_get_features(VirtIODevice *vdev,
+                                             uint64_t features, Error **errp)
+{
+    VHostUserSCSI *s = VHOST_USER_SCSI(vdev);
+
+    // Turn on predefined features supported by this device
+    features |= s->host_features;
+
+    return vhost_scsi_common_get_features(vdev, features, errp);
+}
+
+static Property vhost_user_scsi_properties[] = {
+    DEFINE_PROP_CHR("chardev", VirtIOSCSICommon, conf.chardev),
+    DEFINE_PROP_UINT32("boot_tpgt", VirtIOSCSICommon, conf.boot_tpgt, 0),
+    DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues, 1),
+    DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors,
+                       0xFFFF),
+    DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128),
+    DEFINE_PROP_BIT64("hotplug", VHostUserSCSI, host_features,
+                                                VIRTIO_SCSI_F_HOTPLUG,
+                                                true),
+    DEFINE_PROP_BIT64("param_change", VHostUserSCSI, host_features,
+                                                     VIRTIO_SCSI_F_CHANGE,
+                                                     true),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void vhost_user_scsi_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+    FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(klass);
+
+    dc->props = vhost_user_scsi_properties;
+    set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
+    vdc->realize = vhost_user_scsi_realize;
+    vdc->unrealize = vhost_user_scsi_unrealize;
+    vdc->get_features = vhost_user_scsi_get_features;
+    vdc->set_config = vhost_scsi_common_set_config;
+    vdc->set_status = vhost_user_scsi_set_status;
+    fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path;
+}
+
+static void vhost_user_scsi_instance_init(Object *obj)
+{
+    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(obj);
+    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(obj);
+
+    vsc->feature_bits = user_feature_bits;
+
+    // Add the bootindex property for this object
+    device_add_bootindex_property(obj, &vsc->bootindex, "bootindex", NULL,
+                                  DEVICE(vsc), NULL);
+
+    // Set boot index according the the device config
+    object_property_set_int(obj, vs->conf.bootindex, "bootindex", NULL);
+}
+
+static const TypeInfo vhost_user_scsi_info = {
+    .name = TYPE_VHOST_USER_SCSI,
+    .parent = TYPE_VHOST_SCSI_COMMON,
+    .instance_size = sizeof(VHostUserSCSI),
+    .class_init = vhost_user_scsi_class_init,
+    .instance_init = vhost_user_scsi_instance_init,
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_FW_PATH_PROVIDER },
+        { }
+    },
+};
+
+static void virtio_register_types(void)
+{
+    type_register_static(&vhost_user_scsi_info);
+}
+
+type_init(virtio_register_types)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 21c2b9d..8efafed 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -2077,6 +2077,61 @@  static const TypeInfo vhost_scsi_pci_info = {
 };
 #endif
 
+/* vhost-user-scsi-pci */
+#ifdef CONFIG_VHOST_USER_SCSI
+static Property vhost_user_scsi_pci_properties[] = {
+    DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors,
+                       DEV_NVECTORS_UNSPECIFIED),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void vhost_user_scsi_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
+{
+    VHostUserSCSIPCI *dev = VHOST_USER_SCSI_PCI(vpci_dev);
+    DeviceState *vdev = DEVICE(&dev->vdev);
+    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
+
+    if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) {
+        vpci_dev->nvectors = vs->conf.num_queues + 3;
+    }
+
+    qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
+    object_property_set_bool(OBJECT(vdev), true, "realized", errp);
+}
+
+static void vhost_user_scsi_pci_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioPCIClass *k = VIRTIO_PCI_CLASS(klass);
+    PCIDeviceClass *pcidev_k = PCI_DEVICE_CLASS(klass);
+    k->realize = vhost_user_scsi_pci_realize;
+    set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
+    dc->props = vhost_user_scsi_pci_properties;
+    pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
+    pcidev_k->device_id = PCI_DEVICE_ID_VIRTIO_SCSI;
+    pcidev_k->revision = 0x00;
+    pcidev_k->class_id = PCI_CLASS_STORAGE_SCSI;
+}
+
+static void vhost_user_scsi_pci_instance_init(Object *obj)
+{
+    VHostUserSCSIPCI *dev = VHOST_USER_SCSI_PCI(obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VHOST_USER_SCSI);
+    object_property_add_alias(obj, "bootindex", OBJECT(&dev->vdev),
+                              "bootindex", &error_abort);
+}
+
+static const TypeInfo vhost_user_scsi_pci_info = {
+    .name          = TYPE_VHOST_USER_SCSI_PCI,
+    .parent        = TYPE_VIRTIO_PCI,
+    .instance_size = sizeof(VHostUserSCSIPCI),
+    .instance_init = vhost_user_scsi_pci_instance_init,
+    .class_init    = vhost_user_scsi_pci_class_init,
+};
+#endif /* CONFIG_VHOST_USER_SCSI */
+
 /* vhost-vsock-pci */
 
 #ifdef CONFIG_VHOST_VSOCK
@@ -2553,6 +2608,9 @@  static void virtio_pci_register_types(void)
 #ifdef CONFIG_VHOST_SCSI
     type_register_static(&vhost_scsi_pci_info);
 #endif
+#ifdef CONFIG_VHOST_USER_SCSI
+    type_register_static(&vhost_user_scsi_pci_info);
+#endif
 #ifdef CONFIG_VHOST_VSOCK
     type_register_static(&vhost_vsock_pci_info);
 #endif
diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
index 5e07886..a31761e 100644
--- a/hw/virtio/virtio-pci.h
+++ b/hw/virtio/virtio-pci.h
@@ -33,6 +33,9 @@ 
 #ifdef CONFIG_VHOST_SCSI
 #include "hw/virtio/vhost-scsi.h"
 #endif
+#ifdef CONFIG_VHOST_USER_SCSI
+#include "hw/virtio/vhost-user-scsi.h"
+#endif
 #ifdef CONFIG_VHOST_VSOCK
 #include "hw/virtio/vhost-vsock.h"
 #endif
@@ -44,6 +47,7 @@  typedef struct VirtIOBalloonPCI VirtIOBalloonPCI;
 typedef struct VirtIOSerialPCI VirtIOSerialPCI;
 typedef struct VirtIONetPCI VirtIONetPCI;
 typedef struct VHostSCSIPCI VHostSCSIPCI;
+typedef struct VHostUserSCSIPCI VHostUserSCSIPCI;
 typedef struct VirtIORngPCI VirtIORngPCI;
 typedef struct VirtIOInputPCI VirtIOInputPCI;
 typedef struct VirtIOInputHIDPCI VirtIOInputHIDPCI;
@@ -214,6 +218,17 @@  struct VHostSCSIPCI {
 };
 #endif
 
+#ifdef CONFIG_VHOST_USER_SCSI
+#define TYPE_VHOST_USER_SCSI_PCI "vhost-user-scsi-pci"
+#define VHOST_USER_SCSI_PCI(obj) \
+        OBJECT_CHECK(VHostUserSCSIPCI, (obj), TYPE_VHOST_USER_SCSI_PCI)
+
+struct VHostUserSCSIPCI {
+    VirtIOPCIProxy parent_obj;
+    VHostUserSCSI vdev;
+};
+#endif
+
 /*
  * virtio-blk-pci: This extends VirtioPCIProxy.
  */
diff --git a/include/hw/virtio/vhost-user-scsi.h b/include/hw/virtio/vhost-user-scsi.h
new file mode 100644
index 0000000..01861f7
--- /dev/null
+++ b/include/hw/virtio/vhost-user-scsi.h
@@ -0,0 +1,35 @@ 
+/*
+ * vhost-user-scsi host device
+ *
+ * Copyright (c) 2016 Nutanix Inc. All rights reserved.
+ *
+ * Author:
+ *  Felipe Franciosi <felipe@nutanix.com>
+ *
+ * This file is largely based on "vhost-scsi.h" by:
+ *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#ifndef VHOST_USER_SCSI_H
+#define VHOST_USER_SCSI_H
+
+#include "qemu-common.h"
+#include "hw/qdev.h"
+#include "hw/virtio/virtio-scsi.h"
+#include "hw/virtio/vhost.h"
+#include "hw/virtio/vhost-scsi-common.h"
+
+#define TYPE_VHOST_USER_SCSI "vhost-user-scsi"
+#define VHOST_USER_SCSI(obj) \
+        OBJECT_CHECK(VHostUserSCSI, (obj), TYPE_VHOST_USER_SCSI)
+
+typedef struct VHostUserSCSI {
+    VHostSCSICommon parent_obj;
+    uint64_t host_features;
+} VHostUserSCSI;
+
+#endif /* VHOST_USER_SCSI_H */
diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h
index 39d2177..d52e10c 100644
--- a/include/hw/virtio/virtio-scsi.h
+++ b/include/hw/virtio/virtio-scsi.h
@@ -21,6 +21,7 @@ 
 #include "hw/virtio/virtio.h"
 #include "hw/pci/pci.h"
 #include "hw/scsi/scsi.h"
+#include "sysemu/char.h"
 #include "sysemu/iothread.h"
 
 #define TYPE_VIRTIO_SCSI_COMMON "virtio-scsi-common"
@@ -53,6 +54,10 @@  struct VirtIOSCSIConf {
     char *vhostfd;
     char *wwpn;
 #endif
+#ifdef CONFIG_VHOST_USER_SCSI
+    CharBackend chardev;
+    int32_t bootindex;
+#endif
     uint32_t boot_tpgt;
     IOThread *iothread;
 };