[Qemu-devel] [RFC 9/9] vhost-scsi: add -vhost-scsi host device

[Nicholas A. Bellinger]

From: Stefan Hajnoczi <address@hidden>

This patch adds a new type of host device that drives the vhost_scsi
device.  The syntax to add vhost-scsi is:

  qemu -vhost-scsi id=vhost-scsi0,wwpn=...,tpgt=123

The virtio-scsi emulated device will make use of vhost-scsi to process
virtio-scsi requests inside the kernel and hand them to the in-kernel
SCSI target stack.

Changelog v0 -> v1:

- Add VHOST_SCSI_SET_ENDPOINT call (stefan)
- Enable vhost notifiers for multiple queues (Zhi)
- clear vhost-scsi endpoint on stopped (Zhi)
- Add CONFIG_VHOST_SCSI for QEMU build configure (nab)
- Rename vhost_vring_target -> vhost_scsi_target (mst + nab)
- Add support for VHOST_SCSI_GET_ABI_VERSION ioctl (aliguori + nab)

Signed-off-by: Stefan Hajnoczi <address@hidden>
Signed-off-by: Zhi Yong Wu <address@hidden>
Cc: Anthony Liguori <address@hidden>
Cc: Paolo Bonzini <address@hidden>
Cc: Michael S. Tsirkin <address@hidden>
Signed-off-by: Nicholas Bellinger <address@hidden>
---
 configure            |   10 +++
 hw/Makefile.objs     |    1 +
 hw/qdev-properties.c |   32 +++++++++
 hw/qdev.h            |    3 +
 hw/vhost-scsi.c      |  173 ++++++++++++++++++++++++++++++++++++++++++++++++++
 hw/vhost-scsi.h      |   50 ++++++++++++++
 qemu-common.h        |    1 +
 qemu-config.c        |   16 +++++
 qemu-options.hx      |    4 +
 vl.c                 |   18 +++++
 10 files changed, 308 insertions(+), 0 deletions(-)
 create mode 100644 hw/vhost-scsi.c
 create mode 100644 hw/vhost-scsi.h

diff --git a/configure b/configure
index cef0a71..2291e7e 100755
--- a/configure
+++ b/configure
@@ -144,6 +144,7 @@ libattr=""
 xfs=""
 
 vhost_net="no"
+vhost_scsi="no"
 kvm="no"
 gprof="no"
 debug_tcg="no"
@@ -489,6 +490,7 @@ Haiku)
   usb="linux"
   kvm="yes"
   vhost_net="yes"
+  vhost_scsi="yes"
   if [ "$cpu" = "i386" -o "$cpu" = "x86_64" ] ; then
     audio_possible_drivers="$audio_possible_drivers fmod"
   fi
@@ -794,6 +796,10 @@ for opt do
   ;;
   --enable-vhost-net) vhost_net="yes"
   ;;
+  --disable-vhost-net) vhost_scsi="no"
+  ;;
+  --enable-vhost-net) vhost_scsi="yes"
+  ;;
   --disable-opengl) opengl="no"
   ;;
   --enable-opengl) opengl="yes"
@@ -3059,6 +3065,7 @@ echo "posix_madvise     $posix_madvise"
 echo "uuid support      $uuid"
 echo "libcap-ng support $cap_ng"
 echo "vhost-net support $vhost_net"
+echo "vhost-scsi support $vhost_scsi"
 echo "Trace backend     $trace_backend"
 echo "Trace output file $trace_file-<pid>"
 echo "spice support     $spice"
@@ -3762,6 +3769,9 @@ case "$target_arch2" in
       if test "$vhost_net" = "yes" ; then
         echo "CONFIG_VHOST_NET=y" >> $config_target_mak
       fi
+      if test "$vhost_scsi" = "yes" ; then
+        echo "CONFIG_VHOST_SCSI=y" >> $config_target_mak
+      fi
     fi
 esac
 case "$target_arch2" in
diff --git a/hw/Makefile.objs b/hw/Makefile.objs
index 8327e55..37a0d0e 100644
--- a/hw/Makefile.objs
+++ b/hw/Makefile.objs
@@ -161,6 +161,7 @@ obj-$(CONFIG_VIRTIO) += virtio.o virtio-blk.o 
virtio-balloon.o virtio-net.o
 obj-$(CONFIG_VIRTIO) += virtio-serial-bus.o virtio-scsi.o
 obj-$(CONFIG_SOFTMMU) += vhost_net.o
 obj-$(CONFIG_VHOST_NET) += vhost.o
+obj-$(CONFIG_VHOST_SCSI) += vhost-scsi.o
 obj-$(CONFIG_REALLY_VIRTFS) += 9pfs/
 obj-$(CONFIG_NO_PCI) += pci-stub.o
 obj-$(CONFIG_VGA) += vga.o
diff --git a/hw/qdev-properties.c b/hw/qdev-properties.c
index 24b39e8..0c538d2 100644
--- a/hw/qdev-properties.c
+++ b/hw/qdev-properties.c
@@ -3,6 +3,7 @@
 #include "qerror.h"
 #include "blockdev.h"
 #include "hw/block-common.h"
+#include "vhost-scsi.h"
 
 void *qdev_get_prop_ptr(DeviceState *dev, Property *prop)
 {
@@ -685,6 +686,37 @@ PropertyInfo qdev_prop_vlan = {
     .set   = set_vlan,
 };
 
+/* --- vhost-scsi --- */
+
+static int parse_vhost_scsi(DeviceState *dev, Property *prop, const char *str)
+{
+    VHostSCSI **ptr = qdev_get_prop_ptr(dev, prop);
+
+    *ptr = find_vhost_scsi(str);
+    if (*ptr == NULL) {
+        return -ENOENT;
+    }
+    return 0;
+}
+
+static int print_vhost_scsi(DeviceState *dev, Property *prop,
+                            char *dest, size_t len)
+{
+    VHostSCSI **ptr = qdev_get_prop_ptr(dev, prop);
+
+    if (*ptr) {
+        return snprintf(dest, len, "%s", vhost_scsi_get_id(*ptr));
+    } else {
+        return snprintf(dest, len, "<null>");
+    }
+}
+
+PropertyInfo qdev_prop_vhost_scsi = {
+    .name  = "vhost-scsi",
+    .parse = parse_vhost_scsi,
+    .print = print_vhost_scsi,
+};
+
 /* --- pointer --- */
 
 /* Not a proper property, just for dirty hacks.  TODO Remove it!  */
diff --git a/hw/qdev.h b/hw/qdev.h
index a2cbd9d..ddc0791 100644
--- a/hw/qdev.h
+++ b/hw/qdev.h
@@ -238,6 +238,7 @@ extern PropertyInfo qdev_prop_vlan;
 extern PropertyInfo qdev_prop_pci_devfn;
 extern PropertyInfo qdev_prop_blocksize;
 extern PropertyInfo qdev_prop_pci_host_devaddr;
+extern PropertyInfo qdev_prop_vhost_scsi;
 
 #define DEFINE_PROP(_name, _state, _field, _prop, _type) { \
         .name      = (_name),                                    \
@@ -305,6 +306,8 @@ extern PropertyInfo qdev_prop_pci_host_devaddr;
     DEFINE_PROP_DEFAULT(_n, _s, _f, _d, qdev_prop_blocksize, uint16_t)
 #define DEFINE_PROP_PCI_HOST_DEVADDR(_n, _s, _f) \
     DEFINE_PROP(_n, _s, _f, qdev_prop_pci_host_devaddr, PCIHostDeviceAddress)
+#define DEFINE_PROP_VHOST_SCSI(_n, _s, _f)       \
+    DEFINE_PROP(_n, _s, _f, qdev_prop_vhost_scsi, VHostSCSI*)
 
 #define DEFINE_PROP_END_OF_LIST()               \
     {}
diff --git a/hw/vhost-scsi.c b/hw/vhost-scsi.c
new file mode 100644
index 0000000..9ab314c
--- /dev/null
+++ b/hw/vhost-scsi.c
@@ -0,0 +1,173 @@
+/*
+ * vhost_scsi host device
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ *  Stefan Hajnoczi   <address@hidden>
+ *
+ * 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 <sys/ioctl.h>
+#include "config.h"
+#include "qemu-queue.h"
+#include "vhost-scsi.h"
+#include "vhost.h"
+
+struct VHostSCSI {
+    const char *id;
+    const char *wwpn;
+    uint16_t tpgt;
+    struct vhost_dev dev;
+    struct vhost_virtqueue vqs[3];
+    QLIST_ENTRY(VHostSCSI) list;
+};
+
+static QLIST_HEAD(, VHostSCSI) vhost_scsi_list =
+    QLIST_HEAD_INITIALIZER(vhost_scsi_list);
+
+VHostSCSI *find_vhost_scsi(const char *id)
+{
+    VHostSCSI *vs;
+
+    QLIST_FOREACH(vs, &vhost_scsi_list, list) {
+        if (strcmp(id, vs->id) == 0) {
+            return vs;
+        }
+    }
+    return NULL;
+}
+
+const char *vhost_scsi_get_id(VHostSCSI *vs)
+{
+    return vs->id;
+}
+
+int vhost_scsi_start(VHostSCSI *vs, VirtIODevice *vdev)
+{
+    int ret;
+    struct vhost_scsi_target backend;
+
+    if (!vhost_dev_query(&vs->dev, vdev)) {
+        return -ENOTSUP;
+    }
+
+    vs->dev.nvqs = 3;
+    vs->dev.vqs = vs->vqs;
+
+    ret = vhost_dev_enable_notifiers(&vs->dev, vdev);
+    if (ret < 0) {
+        return ret;
+    }
+
+    ret = vhost_dev_start(&vs->dev, vdev);
+    if (ret < 0) {
+        return ret;
+    }
+
+    memset(&backend, 0, sizeof(backend));
+    ret = ioctl(vs->dev.control, VHOST_SCSI_GET_ABI_VERSION, &backend);
+    if (ret < 0) {
+        ret = -errno;
+        vhost_dev_stop(&vs->dev, vdev);
+        return ret;
+    }
+    if (backend.abi_version > VHOST_SCSI_ABI_VERSION) {
+        fprintf(stderr, "The running tcm_vhost kernel abi_version: %d is 
greater"
+               " than vhost_scsi userspace supports: %d\n", 
backend.abi_version,
+               VHOST_SCSI_ABI_VERSION);
+        ret = -ENOSYS;
+        vhost_dev_stop(&vs->dev, vdev);
+        return ret;
+    }
+    printf("Using TCM_Vhost ABI version: %d\n", backend.abi_version);
+
+    pstrcpy((char *)backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->wwpn);
+    backend.vhost_tpgt = vs->tpgt;
+    ret = ioctl(vs->dev.control, VHOST_SCSI_SET_ENDPOINT, &backend);
+    if (ret < 0) {
+        ret = -errno;
+        vhost_dev_stop(&vs->dev, vdev);
+        return ret;
+    }
+
+    fprintf(stderr, "vhost_scsi_start\n");
+    return 0;
+}
+
+void vhost_scsi_stop(VHostSCSI *vs, VirtIODevice *vdev)
+{
+    fprintf(stderr, "vhost_scsi_stop\n");
+
+    int ret;
+    struct vhost_scsi_target backend;
+
+    pstrcpy((char *)backend.vhost_wwpn, sizeof(backend.vhost_wwpn), vs->wwpn);
+    backend.vhost_tpgt = vs->tpgt;
+    ret = ioctl(vs->dev.control, VHOST_SCSI_CLEAR_ENDPOINT, &backend);
+    if (ret < 0) {
+        fprintf(stderr, "Failed to clear endpoint\n");
+    }
+
+    vhost_dev_stop(&vs->dev, vdev);
+}
+
+static VHostSCSI *vhost_scsi_add(const char *id, const char *wwpn,
+                                 uint16_t tpgt)
+{
+    VHostSCSI *vs = g_malloc0(sizeof(*vs));
+    int ret;
+
+    /* TODO set up vhost-scsi device and bind to tcm_vhost/$wwpm/tpgt_$tpgt */
+    fprintf(stderr, "wwpn = \"%s\" tpgt = \"%u\"\n", id, tpgt);
+
+    ret = vhost_dev_init(&vs->dev, -1, "/dev/vhost-scsi", false);
+    if (ret < 0) {
+        fprintf(stderr, "vhost-scsi: vhost initialization failed: %s\n",
+                strerror(-ret));
+        return NULL;
+    }
+    vs->dev.backend_features = 0;
+    vs->dev.acked_features = 0;
+
+    vs->id = g_strdup(id);
+    vs->wwpn = g_strdup(wwpn);
+    vs->tpgt = tpgt;
+    QLIST_INSERT_HEAD(&vhost_scsi_list, vs, list);
+
+    return vs;
+}
+
+VHostSCSI *vhost_scsi_add_opts(QemuOpts *opts)
+{
+    const char *id;
+    const char *wwpn;
+    uint64_t tpgt;
+
+    id = qemu_opts_id(opts);
+    if (!id) {
+        fprintf(stderr, "vhost-scsi: no id specified\n");
+        return NULL;
+    }
+    if (find_vhost_scsi(id)) {
+        fprintf(stderr, "duplicate vhost-scsi: \"%s\"\n", id);
+        return NULL;
+    }
+
+    wwpn = qemu_opt_get(opts, "wwpn");
+    if (!wwpn) {
+        fprintf(stderr, "vhost-scsi: \"%s\" missing wwpn\n", id);
+        return NULL;
+    }
+
+    tpgt = qemu_opt_get_number(opts, "tpgt", UINT64_MAX);
+    if (tpgt > UINT16_MAX) {
+        fprintf(stderr, "vhost-scsi: \"%s\" needs a 16-bit tpgt\n", id);
+        return NULL;
+    }
+
+    return vhost_scsi_add(id, wwpn, tpgt);
+}
diff --git a/hw/vhost-scsi.h b/hw/vhost-scsi.h
new file mode 100644
index 0000000..fb6d37a
--- /dev/null
+++ b/hw/vhost-scsi.h
@@ -0,0 +1,50 @@
+/*
+ * vhost_scsi host device
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ *  Stefan Hajnoczi   <address@hidden>
+ *
+ * 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_SCSI_H
+#define VHOST_SCSI_H
+
+#include "qemu-common.h"
+#include "qemu-option.h"
+
+/*
+ * Used by QEMU userspace to ensure a consistent vhost-scsi ABI.
+ *
+ * ABI Rev 0: All pre 2012 revisions used by prototype out-of-tree code
+ * ABI Rev 1: 2012 version for v3.6 kernel merge candidate
+ */
+
+#define VHOST_SCSI_ABI_VERSION 1
+
+/* TODO #include <linux/vhost.h> properly */
+/* For VHOST_SCSI_SET_ENDPOINT/VHOST_SCSI_CLEAR_ENDPOINT ioctl */
+struct vhost_scsi_target {
+    int abi_version;
+    unsigned char vhost_wwpn[224];
+    unsigned short vhost_tpgt;
+};
+
+#define VHOST_VIRTIO 0xAF
+#define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct 
vhost_scsi_target)
+#define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct 
vhost_scsi_target)
+#define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, struct 
vhost_scsi_target)
+
+VHostSCSI *find_vhost_scsi(const char *id);
+const char *vhost_scsi_get_id(VHostSCSI *vs);
+
+VHostSCSI *vhost_scsi_add_opts(QemuOpts *opts);
+
+int vhost_scsi_start(VHostSCSI *vs, VirtIODevice *vdev);
+void vhost_scsi_stop(VHostSCSI *vs, VirtIODevice *vdev);
+
+#endif
diff --git a/qemu-common.h b/qemu-common.h
index 7c8dac8..ce431b7 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -262,6 +262,7 @@ typedef struct EventNotifier EventNotifier;
 typedef struct VirtIODevice VirtIODevice;
 typedef struct QEMUSGList QEMUSGList;
 typedef struct SHPCDevice SHPCDevice;
+typedef struct VHostSCSI VHostSCSI;
 
 typedef uint64_t pcibus_t;
 
diff --git a/qemu-config.c b/qemu-config.c
index 5c3296b..33399ea 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -626,6 +626,21 @@ QemuOptsList qemu_boot_opts = {
     },
 };
 
+QemuOptsList qemu_vhost_scsi_opts = {
+    .name = "vhost-scsi",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_vhost_scsi_opts.head),
+    .desc = {
+        {
+            .name = "wwpn",
+            .type = QEMU_OPT_STRING,
+        }, {
+            .name = "tpgt",
+            .type = QEMU_OPT_NUMBER,
+        },
+        { /* end of list */ }
+    },
+};
+
 static QemuOptsList *vm_config_groups[32] = {
     &qemu_drive_opts,
     &qemu_chardev_opts,
@@ -641,6 +656,7 @@ static QemuOptsList *vm_config_groups[32] = {
     &qemu_machine_opts,
     &qemu_boot_opts,
     &qemu_iscsi_opts,
+    &qemu_vhost_scsi_opts,
     NULL,
 };
 
diff --git a/qemu-options.hx b/qemu-options.hx
index dc68e15..c3911a8 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -561,6 +561,10 @@ possible drivers and properties, use @code{-device ?} and
 ETEXI
 
 DEFHEADING()
+DEF("vhost-scsi", HAS_ARG, QEMU_OPTION_vhost_scsi,
+    "-virtio-scsi wwpn=string0,tpgt=number0\n"
+    "                add vhost-scsi device\n",
+    QEMU_ARCH_ALL)
 
 DEFHEADING(File system options:)
 
diff --git a/vl.c b/vl.c
index 8904db1..063ca1d 100644
--- a/vl.c
+++ b/vl.c
@@ -143,6 +143,7 @@ int main(int argc, char **argv)
 #include "qemu-options.h"
 #include "qmp-commands.h"
 #include "main-loop.h"
+#include "hw/vhost-scsi.h"
 #ifdef CONFIG_VIRTFS
 #include "fsdev/qemu-fsdev.h"
 #endif
@@ -1854,6 +1855,14 @@ static int fsdev_init_func(QemuOpts *opts, void *opaque)
 }
 #endif
 
+static int vhost_scsi_init_func(QemuOpts *opts, void *opaque)
+{
+    if (!vhost_scsi_add_opts(opts)) {
+        return -1;
+    }
+    return 0;
+}
+
 static int mon_init_func(QemuOpts *opts, void *opaque)
 {
     CharDriverState *chr;
@@ -2613,6 +2622,11 @@ int main(int argc, char **argv, char **envp)
                 }
                 break;
 #endif
+            case QEMU_OPTION_vhost_scsi:
+                if (!qemu_opts_parse(qemu_find_opts("vhost-scsi"), optarg, 0)) 
{
+                    exit(1);
+                }
+                break;
 #ifdef CONFIG_SLIRP
             case QEMU_OPTION_tftp:
                 legacy_tftp_prefix = optarg;
@@ -3333,6 +3347,10 @@ int main(int argc, char **argv, char **envp)
         exit(1);
     }
 #endif
+    if (qemu_opts_foreach(qemu_find_opts("vhost-scsi"),
+                          vhost_scsi_init_func, NULL, 1)) {
+        exit(1);
+    }
 
     os_daemonize();
 
-- 
1.7.2.5