[Qemu-devel] [PATCH 0/8] virtio-rng: hardware random number generator device

[Qemu-devel] [PATCH 0/8] virtio-rng: hardware random number generator device

[Amit Shah]

Hello,

Reviving this series last sent by Anthony to the list.  The
differences are minimal from the time Anthony sent, just rebasing to
the current tree and fixing a couple of minor bugs.

I've not really looked in detail at the object patches -- mostly just
concerned about the device itself.

Please review and apply if appropriate.

Changes from last submission:
- Fix a few typos/whitespaces in rng.h
- Switch to virtqueue_get_avail_bytes(): helps remove the
  savevm/loadvm complexities and provides a cleaner interface
- Remove the older qevent hunks that got left behind
- Rebase to master
- Bugfix: rng_backend_request_entropy() in chr_read() should pass len,
  not size
- Do not request for more entropy in chr_read() once the current
  request is served; there are other ways this notification will go
  out.


Amit Shah (1):
  virtio-rng: hardware random number generator device

Anthony Liguori (7):
  object: add object_property_add_bool (v2)
  qdev: add realized property and make adding child bus implied by
    realize
  vl: add -object option to create QOM objects from the command line
  vl: add -late-object to create QOM objects after machine init
  rng: add RndBackend abstract object class
  rng-urandom: add an RNG backend that uses /dev/urandom
  rng-egd: introduce EGD compliant RNG backend

 Makefile.objs          |    2 +
 backends/Makefile.objs |    1 +
 backends/rng-egd.c     |  215 ++++++++++++++++++++++++++++++++++++++++++++++++
 backends/rng-urandom.c |  144 ++++++++++++++++++++++++++++++++
 backends/rng.c         |   93 +++++++++++++++++++++
 hw/Makefile.objs       |    1 +
 hw/pci.h               |    1 +
 hw/qdev.c              |   36 ++++++++-
 hw/s390-virtio-bus.c   |   37 ++++++++
 hw/s390-virtio-bus.h   |    2 +
 hw/virtio-pci.c        |   60 +++++++++++++
 hw/virtio-pci.h        |    2 +
 hw/virtio-rng.c        |  149 +++++++++++++++++++++++++++++++++
 hw/virtio-rng.h        |   24 ++++++
 hw/virtio.h            |    3 +
 include/qemu/object.h  |   16 ++++
 include/qemu/rng.h     |   93 +++++++++++++++++++++
 qemu-config.c          |   20 +++++
 qemu-options.hx        |   20 +++++
 qom/object.c           |   56 +++++++++++++
 vl.c                   |   62 ++++++++++++++
 21 files changed, 1036 insertions(+), 1 deletions(-)
 create mode 100644 backends/Makefile.objs
 create mode 100644 backends/rng-egd.c
 create mode 100644 backends/rng-urandom.c
 create mode 100644 backends/rng.c
 create mode 100644 hw/virtio-rng.c
 create mode 100644 hw/virtio-rng.h
 create mode 100644 include/qemu/rng.h

-- 
1.7.7.6

[Qemu-devel] [PATCH 1/8] object: add object_property_add_bool (v2)

[Amit Shah]

From: Anthony Liguori <aliguori@us.ibm.com>

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
 include/qemu/object.h |   16 ++++++++++++++
 qom/object.c          |   56 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+), 0 deletions(-)

diff --git a/include/qemu/object.h b/include/qemu/object.h
index cc75fee..be707f1 100644
--- a/include/qemu/object.h
+++ b/include/qemu/object.h
@@ -947,6 +947,22 @@ void object_property_add_str(Object *obj, const char *name,
                              struct Error **errp);
 
 /**
+ * object_property_add_bool:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @get: the getter or NULL if the property is write-only.
+ * @set: the setter or NULL if the property is read-only
+ * @errp: if an error occurs, a pointer to an area to store the error
+ *
+ * Add a bool property using getters/setters.  This function will add a
+ * property of type 'bool'.
+ */
+void object_property_add_bool(Object *obj, const char *name,
+                              bool (*get)(Object *, struct Error **),
+                              void (*set)(Object *, bool, struct Error **),
+                              struct Error **errp);
+
+/**
  * object_child_foreach:
  * @obj: the object whose children will be navigated
  * @fn: the iterator function to be called
diff --git a/qom/object.c b/qom/object.c
index e3e9242..d7092b0 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -1183,6 +1183,62 @@ void object_property_add_str(Object *obj, const char *name,
                         prop, errp);
 }
 
+typedef struct BoolProperty
+{
+    bool (*get)(Object *, Error **);
+    void (*set)(Object *, bool, Error **);
+} BoolProperty;
+
+static void property_get_bool(Object *obj, Visitor *v, void *opaque,
+                              const char *name, Error **errp)
+{
+    BoolProperty *prop = opaque;
+    bool value;
+
+    value = prop->get(obj, errp);
+    visit_type_bool(v, &value, name, errp);
+}
+
+static void property_set_bool(Object *obj, Visitor *v, void *opaque,
+                              const char *name, Error **errp)
+{
+    BoolProperty *prop = opaque;
+    bool value;
+    Error *local_err = NULL;
+
+    visit_type_bool(v, &value, name, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    prop->set(obj, value, errp);
+}
+
+static void property_release_bool(Object *obj, const char *name,
+                                  void *opaque)
+{
+    BoolProperty *prop = opaque;
+    g_free(prop);
+}
+
+void object_property_add_bool(Object *obj, const char *name,
+                              bool (*get)(Object *, Error **),
+                              void (*set)(Object *, bool, Error **),
+                              Error **errp)
+{
+    BoolProperty *prop = g_malloc0(sizeof(*prop));
+
+    prop->get = get;
+    prop->set = set;
+
+    object_property_add(obj, name, "bool",
+                        get ? property_get_bool : NULL,
+                        set ? property_set_bool : NULL,
+                        property_release_bool,
+                        prop, errp);
+}
+
 static char *qdev_get_type(Object *obj, Error **errp)
 {
     return g_strdup(object_get_typename(obj));
-- 
1.7.7.6

[Qemu-devel] [PATCH 2/8] qdev: add realized property and make adding child bus implied by realize

[Amit Shah]

From: Anthony Liguori <aliguori@us.ibm.com>

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
 hw/qdev.c |   36 +++++++++++++++++++++++++++++++++++-
 1 files changed, 35 insertions(+), 1 deletions(-)

diff --git a/hw/qdev.c b/hw/qdev.c
index 9b9aba3..5e34c22 100644
--- a/hw/qdev.c
+++ b/hw/qdev.c
@@ -95,7 +95,6 @@ static void bus_add_child(BusState *bus, DeviceState *child)
 void qdev_set_parent_bus(DeviceState *dev, BusState *bus)
 {
     dev->parent_bus = bus;
-    bus_add_child(bus, dev);
 }
 
 /* Create a new device.  This only initializes the device state structure
@@ -151,6 +150,10 @@ int qdev_init(DeviceState *dev)
 
     assert(dev->state == DEV_STATE_CREATED);
 
+    if (dev->parent_bus) {
+        bus_add_child(dev->parent_bus, dev);
+    }
+
     rc = dc->init(dev);
     if (rc < 0) {
         qdev_free(dev);
@@ -654,6 +657,33 @@ void qdev_property_add_static(DeviceState *dev, Property *prop,
     assert_no_error(local_err);
 }
 
+static bool qdev_prop_get_realized(Object *obj, Error **errp)
+{
+    DeviceState *dev = DEVICE(obj);
+
+    return (dev->state == DEV_STATE_INITIALIZED);
+}
+
+static void qdev_prop_set_realized(Object *obj, bool value, Error **errp)
+{
+    DeviceState *dev = DEVICE(obj);
+    bool realized = (dev->state == DEV_STATE_INITIALIZED);
+
+    if (realized == value) {
+        return;
+    }
+
+    if (realized && !value) {
+        error_set(errp, QERR_PERMISSION_DENIED);
+        return;
+    }
+
+    if (qdev_init(dev) < 0) {
+        error_set(errp, QERR_DEVICE_INIT_FAILED, "");
+        return;
+    }
+}
+
 static void device_initfn(Object *obj)
 {
     DeviceState *dev = DEVICE(obj);
@@ -678,6 +708,10 @@ static void device_initfn(Object *obj)
     } while (class != object_class_by_name(TYPE_DEVICE));
     qdev_prop_set_globals(dev);
 
+    object_property_add_bool(obj, "realized",
+                             qdev_prop_get_realized, qdev_prop_set_realized,
+                             NULL);
+
     object_property_add_link(OBJECT(dev), "parent_bus", TYPE_BUS,
                              (Object **)&dev->parent_bus, NULL);
 }
-- 
1.7.7.6

[Qemu-devel] [PATCH 3/8] vl: add -object option to create QOM objects from the command line

[Amit Shah]

From: Anthony Liguori <aliguori@us.ibm.com>

This will create a new QOM object in the '/objects' path.  Note that properties
are set in order which allows for simple objects to be initialized entirely
with this option and then realized.

This option is roughly equivalent to -device but for things that are not
devices.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
 qemu-config.c   |   10 ++++++++++
 qemu-options.hx |    8 ++++++++
 vl.c            |   54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 72 insertions(+), 0 deletions(-)

diff --git a/qemu-config.c b/qemu-config.c
index cd1ec21..d695bdf 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -653,6 +653,15 @@ QemuOptsList qemu_boot_opts = {
     },
 };
 
+QemuOptsList qemu_object_opts = {
+    .name = "object",
+    .implied_opt_name = "qom-type",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
+    .desc = {
+        { }
+    },
+};
+
 static QemuOptsList *vm_config_groups[32] = {
     &qemu_drive_opts,
     &qemu_chardev_opts,
@@ -669,6 +678,7 @@ static QemuOptsList *vm_config_groups[32] = {
     &qemu_boot_opts,
     &qemu_iscsi_opts,
     &qemu_sandbox_opts,
+    &qemu_object_opts,
     NULL,
 };
 
diff --git a/qemu-options.hx b/qemu-options.hx
index 46f0539..b72151e 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2852,6 +2852,14 @@ STEXI
 Enable FIPS 140-2 compliance mode.
 ETEXI
 
+DEF("object", HAS_ARG, QEMU_OPTION_object,
+    "-object TYPENAME[,PROP1=VALUE1,...]\n"
+    "                create an new object of type TYPENAME setting properties\n"
+    "                in the order they are specified.  Note that the 'id'\n"
+    "                property must be set.  These objects are placed in the\n"
+    "                '/objects' path.\n",
+    QEMU_ARCH_ALL)
+
 HXCOMM This is the last statement. Insert new options before this line!
 STEXI
 @end table
diff --git a/vl.c b/vl.c
index ee3c43a..eabf47b 100644
--- a/vl.c
+++ b/vl.c
@@ -168,6 +168,7 @@ int main(int argc, char **argv)
 #include "osdep.h"
 
 #include "ui/qemu-spice.h"
+#include "qapi/string-input-visitor.h"
 
 //#define DEBUG_NET
 //#define DEBUG_SLIRP
@@ -2357,6 +2358,53 @@ static void free_and_trace(gpointer mem)
     free(mem);
 }
 
+static int object_set_property(const char *name, const char *value, void *opaque)
+{
+    Object *obj = OBJECT(opaque);
+    StringInputVisitor *siv;
+    Error *local_err = NULL;
+
+    if (strcmp(name, "qom-type") == 0 || strcmp(name, "id") == 0) {
+        return 0;
+    }
+
+    siv = string_input_visitor_new(value);
+    object_property_set(obj, string_input_get_visitor(siv), name, &local_err);
+    string_input_visitor_cleanup(siv);
+
+    if (local_err) {
+        qerror_report_err(local_err);
+        error_free(local_err);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int object_create(QemuOpts *opts, void *opaque)
+{
+    const char *type = qemu_opt_get(opts, "qom-type");
+    const char *id = qemu_opts_id(opts);
+    Object *obj;
+
+    g_assert(type != NULL);
+
+    if (id == NULL) {
+        qerror_report(QERR_MISSING_PARAMETER, "id");
+        return -1;
+    }
+
+    obj = object_new(type);
+    if (qemu_opt_foreach(opts, object_set_property, obj, 1) < 0) {
+        return -1;
+    }
+
+    object_property_add_child(container_get(object_get_root(), "/objects"),
+                              id, obj, NULL);
+
+    return 0;
+}
+
 int qemu_init_main_loop(void)
 {
     return main_loop_init();
@@ -3308,6 +3356,9 @@ int main(int argc, char **argv, char **envp)
                 if (!opts) {
                     exit(0);
                 }
+		break;
+            case QEMU_OPTION_object:
+                opts = qemu_opts_parse(qemu_find_opts("object"), optarg, 1);
                 break;
             default:
                 os_parse_cmd_args(popt->index, optarg);
@@ -3319,6 +3370,9 @@ int main(int argc, char **argv, char **envp)
     if (qemu_opts_foreach(qemu_find_opts("sandbox"), parse_sandbox, NULL, 0)) {
         exit(1);
     }
+    if (qemu_opts_foreach(qemu_find_opts("object"), object_create, NULL, 0) != 0) {
+        exit(1);
+    }
 
     if (machine == NULL) {
         fprintf(stderr, "No machine found.\n");
-- 
1.7.7.6

[Qemu-devel] [PATCH 4/8] vl: add -late-object to create QOM objects after machine init

[Amit Shah]

From: Anthony Liguori <aliguori@us.ibm.com>

In order to create qdev objects via -late-object, we almost always have to
specify the parent_bus which is usually created during machine init.  Until we
properly support two stage init, introduce a -late-object option that allows for
creation of objects post-machine init.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
 qemu-config.c   |   10 ++++++++++
 qemu-options.hx |   12 ++++++++++++
 vl.c            |   14 +++++++++++---
 3 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/qemu-config.c b/qemu-config.c
index d695bdf..537acd1 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -662,6 +662,15 @@ QemuOptsList qemu_object_opts = {
     },
 };
 
+QemuOptsList qemu_late_object_opts = {
+    .name = "late-object",
+    .implied_opt_name = "qom-type",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_late_object_opts.head),
+    .desc = {
+        { }
+    },
+};
+
 static QemuOptsList *vm_config_groups[32] = {
     &qemu_drive_opts,
     &qemu_chardev_opts,
@@ -679,6 +688,7 @@ static QemuOptsList *vm_config_groups[32] = {
     &qemu_iscsi_opts,
     &qemu_sandbox_opts,
     &qemu_object_opts,
+    &qemu_late_object_opts,
     NULL,
 };
 
diff --git a/qemu-options.hx b/qemu-options.hx
index b72151e..a0fe038 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2860,6 +2860,18 @@ DEF("object", HAS_ARG, QEMU_OPTION_object,
     "                '/objects' path.\n",
     QEMU_ARCH_ALL)
 
+DEF("late-object", HAS_ARG, QEMU_OPTION_late_object,
+    "-late-object TYPENAME[,PROP1=VALUE1,...]\n"
+    "                create an new object of type TYPENAME setting properties\n"
+    "                in the order they are specified.  Note that the 'id'\n"
+    "                property must be set.  These objects are placed in the\n"
+    "                '/objects' path.\n"
+    "\n"
+    "                Late objects are made after machine\n"
+    "                initialization so they can refer to objects created by\n"
+    "                the machine init function.\n",
+    QEMU_ARCH_ALL)
+
 HXCOMM This is the last statement. Insert new options before this line!
 STEXI
 @end table
diff --git a/vl.c b/vl.c
index eabf47b..61b4666 100644
--- a/vl.c
+++ b/vl.c
@@ -2395,13 +2395,14 @@ static int object_create(QemuOpts *opts, void *opaque)
     }
 
     obj = object_new(type);
-    if (qemu_opt_foreach(opts, object_set_property, obj, 1) < 0) {
-        return -1;
-    }
 
     object_property_add_child(container_get(object_get_root(), "/objects"),
                               id, obj, NULL);
 
+    if (qemu_opt_foreach(opts, object_set_property, obj, 1) < 0) {
+        return -1;
+    }
+
     return 0;
 }
 
@@ -3360,6 +3361,9 @@ int main(int argc, char **argv, char **envp)
             case QEMU_OPTION_object:
                 opts = qemu_opts_parse(qemu_find_opts("object"), optarg, 1);
                 break;
+            case QEMU_OPTION_late_object:
+                opts = qemu_opts_parse(qemu_find_opts("late-object"), optarg, 1);
+                break;
             default:
                 os_parse_cmd_args(popt->index, optarg);
             }
@@ -3706,6 +3710,10 @@ int main(int argc, char **argv, char **envp)
 
     current_machine = machine;
 
+    if (qemu_opts_foreach(qemu_find_opts("late-object"), object_create, NULL, 0) != 0) {
+        exit(1);
+    }
+
     /* init USB devices */
     if (usb_enabled) {
         if (foreach_device_config(DEV_USB, usb_parse) < 0)
-- 
1.7.7.6

[Qemu-devel] [PATCH 5/8] rng: add RndBackend abstract object class

[Amit Shah]

From: Anthony Liguori <aliguori@us.ibm.com>

This is the backend used by devices that need to request entropy.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
 Makefile.objs          |    2 +
 backends/Makefile.objs |    1 +
 backends/rng.c         |   93 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/qemu/rng.h     |   93 ++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 189 insertions(+), 0 deletions(-)
 create mode 100644 backends/Makefile.objs
 create mode 100644 backends/rng.c
 create mode 100644 include/qemu/rng.h

diff --git a/Makefile.objs b/Makefile.objs
index 74b3542..a2decc5 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -100,6 +100,8 @@ common-obj-y += vl.o
 
 common-obj-$(CONFIG_SLIRP) += slirp/
 
+common-obj-y += backends/
+
 ######################################################################
 # libseccomp
 ifeq ($(CONFIG_SECCOMP),y)
diff --git a/backends/Makefile.objs b/backends/Makefile.objs
new file mode 100644
index 0000000..06e08c7
--- /dev/null
+++ b/backends/Makefile.objs
@@ -0,0 +1 @@
+common-obj-y += rng.o
diff --git a/backends/rng.c b/backends/rng.c
new file mode 100644
index 0000000..06f2611
--- /dev/null
+++ b/backends/rng.c
@@ -0,0 +1,93 @@
+/*
+ * QEMU Random Number Generator Backend
+ *
+ * Copyright IBM, Corp. 2012
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/rng.h"
+#include "qerror.h"
+
+void rng_backend_request_entropy(RngBackend *s, size_t size,
+                                 EntropyReceiveFunc *receive_entropy,
+                                 void *opaque)
+{
+    RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
+
+    if (k->request_entropy) {
+        k->request_entropy(s, size, receive_entropy, opaque);
+    }
+}
+
+void rng_backend_cancel_requests(RngBackend *s)
+{
+    RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
+
+    if (k->cancel_requests) {
+        k->cancel_requests(s);
+    }
+}
+
+static bool rng_backend_prop_get_opened(Object *obj, Error **errp)
+{
+    RngBackend *s = RNG_BACKEND(obj);
+
+    return s->opened;
+}
+
+void rng_backend_open(RngBackend *s, Error **errp)
+{
+    object_property_set_bool(OBJECT(s), true, "opened", errp);
+}
+
+static void rng_backend_prop_set_opened(Object *obj, bool value, Error **errp)
+{
+    RngBackend *s = RNG_BACKEND(obj);
+    RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
+
+    if (value == s->opened) {
+        return;
+    }
+
+    if (!value && s->opened) {
+        error_set(errp, QERR_PERMISSION_DENIED);
+        return;
+    }
+
+    if (k->opened) {
+        k->opened(s, errp);
+    }
+
+    if (!error_is_set(errp)) {
+        s->opened = value;
+    }
+}
+
+static void rng_backend_init(Object *obj)
+{
+    object_property_add_bool(obj, "opened",
+                             rng_backend_prop_get_opened,
+                             rng_backend_prop_set_opened,
+                             NULL);
+}
+
+static TypeInfo rng_backend_info = {
+    .name = TYPE_RNG_BACKEND,
+    .parent = TYPE_OBJECT,
+    .instance_size = sizeof(RngBackend),
+    .instance_init = rng_backend_init,
+    .class_size = sizeof(RngBackendClass),
+    .abstract = true,
+};
+
+static void register_types(void)
+{
+    type_register_static(&rng_backend_info);
+}
+
+type_init(register_types);
diff --git a/include/qemu/rng.h b/include/qemu/rng.h
new file mode 100644
index 0000000..9836463
--- /dev/null
+++ b/include/qemu/rng.h
@@ -0,0 +1,93 @@
+/*
+ * QEMU Random Number Generator Backend
+ *
+ * Copyright IBM, Corp. 2012
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef QEMU_RNG_H
+#define QEMU_RNG_H
+
+#include "qemu/object.h"
+#include "qemu-common.h"
+#include "error.h"
+
+#define TYPE_RNG_BACKEND "rng-backend"
+#define RNG_BACKEND(obj) \
+    OBJECT_CHECK(RngBackend, (obj), TYPE_RNG_BACKEND)
+#define RNG_BACKEND_GET_CLASS(obj) \
+    OBJECT_GET_CLASS(RngBackendClass, (obj), TYPE_RNG_BACKEND)
+#define RNG_BACKEND_CLASS(klass) \
+    OBJECT_CLASS_CHECK(RngBackendClass, (klass), TYPE_RNG_BACKEND)
+
+typedef struct RngBackendClass RngBackendClass;
+typedef struct RngBackend RngBackend;
+
+typedef void (EntropyReceiveFunc)(void *opaque,
+                                  const void *data,
+                                  size_t size);
+
+struct RngBackendClass
+{
+    ObjectClass parent_class;
+
+    void (*request_entropy)(RngBackend *s, size_t size,
+                            EntropyReceiveFunc *recieve_entropy, void *opaque);
+    void (*cancel_requests)(RngBackend *s);
+
+    void (*opened)(RngBackend *s, Error **errp);
+};
+
+struct RngBackend
+{
+    Object parent;
+
+    /*< protected >*/
+    bool opened;
+};
+
+/**
+ * rng_backend_request_entropy:
+ * @s: the backend to request entropy from
+ * @size: the number of bytes of data to request
+ * @receive_entropy: a function to be invoked when entropy is available
+ * @opaque: data that should be passed to @receive_entropy
+ *
+ * This function is used by the front-end to request entropy from an entropy
+ * source.  This function can be called multiple times before @receive_entropy
+ * is invoked with different values of @receive_entropy and @opaque.  The
+ * backend will queue each request and handle appropriately.
+ *
+ * The backend does not need to pass the full amount of data to @receive_entropy
+ * but will pass a a value greater than 0.
+ */
+void rng_backend_request_entropy(RngBackend *s, size_t size,
+                                 EntropyReceiveFunc *receive_entropy,
+                                 void *opaque);
+
+/**
+ * rng_backend_cancel_requests:
+ * @s: the backend to cancel all pending requests in
+ *
+ * Cancels all pending requests submitted by @rng_backend_request_entropy.  This
+ * should be used by a device during reset or in preparation for live migration
+ * to stop tracking any request.
+ */
+void rng_backend_cancel_requests(RngBackend *s);
+
+/**
+ * rng_backend_open:
+ * @s: the backend to open
+ * @errp: a pointer to return the #Error object if an error occurs.
+ *
+ * This function will open the backend if it is not already open.  Calling this
+ * function on an already opened backend will not result in an error.
+ */
+void rng_backend_open(RngBackend *s, Error **errp);
+
+#endif
-- 
1.7.7.6

[Qemu-devel] [PATCH 6/8] rng-urandom: add an RNG backend that uses /dev/urandom

[Amit Shah]

From: Anthony Liguori <aliguori@us.ibm.com>

The filename can be overridden but it expects a non-blocking source of entropy.
A typical invocation would be:

qemu -object rng-urandom,id=rng0 -device virtio-rng-pci,rng=rng0

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
 backends/Makefile.objs |    2 +-
 backends/rng-urandom.c |  144 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 145 insertions(+), 1 deletions(-)
 create mode 100644 backends/rng-urandom.c

diff --git a/backends/Makefile.objs b/backends/Makefile.objs
index 06e08c7..423c9df 100644
--- a/backends/Makefile.objs
+++ b/backends/Makefile.objs
@@ -1 +1 @@
-common-obj-y += rng.o
+common-obj-y += rng.o rng-urandom.o
diff --git a/backends/rng-urandom.c b/backends/rng-urandom.c
new file mode 100644
index 0000000..7fbe886
--- /dev/null
+++ b/backends/rng-urandom.c
@@ -0,0 +1,144 @@
+/*
+ * QEMU Random Number Generator Backend
+ *
+ * Copyright IBM, Corp. 2012
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/rng.h"
+#include "qerror.h"
+
+#define TYPE_RNG_URANDOM "rng-urandom"
+#define RNG_URANDOM(obj) OBJECT_CHECK(RndURandom, (obj), TYPE_RNG_URANDOM)
+
+typedef struct RndURandom
+{
+    RngBackend parent;
+
+    int fd;
+    char *filename;
+    GSList *pending_data;
+} RndURandom;
+
+/**
+ * A simple and incomplete backend to request entropy from /dev/urandom.
+ *
+ * This backend exposes an additional "filename" property that can be used to
+ * set the filename to use to open the backend.
+ */
+static void rng_urandom_request_entropy(RngBackend *b, size_t size,
+                                        EntropyReceiveFunc *receive_entropy,
+                                        void *opaque)
+{
+    RndURandom *s = RNG_URANDOM(b);
+    uint8_t data[size];
+    ssize_t ret;
+
+    g_assert(s->fd != -1);
+
+    do {
+        ret = read(s->fd, data, size);
+    } while (ret == -1 && errno == EINTR);
+
+    g_assert(ret != -1);
+
+    /* FIXME: needs to be done via a BH */
+    receive_entropy(opaque, data, ret);
+}
+
+static void rng_urandom_opened(RngBackend *b, Error **errp)
+{
+    RndURandom *s = RNG_URANDOM(b);
+
+    if (s->filename == NULL) {
+        error_set(errp, QERR_INVALID_PARAMETER_VALUE,
+                  "filename", "a valid filename");
+    } else {
+        s->fd = open(s->filename, O_RDONLY);
+
+        if (s->fd == -1) {
+            error_set(errp, QERR_OPEN_FILE_FAILED, s->filename);
+        }
+    }
+}
+
+static char *rng_urandom_get_filename(Object *obj, Error **errp)
+{
+    RndURandom *s = RNG_URANDOM(obj);
+
+    if (s->filename) {
+        return g_strdup(s->filename);
+    }
+
+    return NULL;
+}
+
+static void rng_urandom_set_filename(Object *obj, const char *filename,
+                                 Error **errp)
+{
+    RngBackend *b = RNG_BACKEND(obj);
+    RndURandom *s = RNG_URANDOM(obj);
+
+    if (b->opened) {
+        error_set(errp, QERR_PERMISSION_DENIED);
+        return;
+    }
+
+    if (s->filename) {
+        g_free(s->filename);
+    }
+
+    s->filename = g_strdup(filename);
+}
+
+static void rng_urandom_init(Object *obj)
+{
+    RndURandom *s = RNG_URANDOM(obj);
+
+    object_property_add_str(obj, "filename",
+                            rng_urandom_get_filename,
+                            rng_urandom_set_filename,
+                            NULL);
+
+    s->filename = g_strdup("/dev/urandom");
+}
+
+static void rng_urandom_finalize(Object *obj)
+{
+    RndURandom *s = RNG_URANDOM(obj);
+
+    if (s->fd != -1) {
+        close(s->fd);
+    }
+
+    g_free(s->filename);
+}
+
+static void rng_urandom_class_init(ObjectClass *klass, void *data)
+{
+    RngBackendClass *rbc = RNG_BACKEND_CLASS(klass);
+
+    rbc->request_entropy = rng_urandom_request_entropy;
+    rbc->opened = rng_urandom_opened;
+}
+
+static TypeInfo rng_urandom_info = {
+    .name = TYPE_RNG_URANDOM,
+    .parent = TYPE_RNG_BACKEND,
+    .instance_size = sizeof(RndURandom),
+    .class_init = rng_urandom_class_init,
+    .instance_init = rng_urandom_init,
+    .instance_finalize = rng_urandom_finalize,
+};
+
+static void register_types(void)
+{
+    type_register_static(&rng_urandom_info);
+}
+
+type_init(register_types);
-- 
1.7.7.6

[Qemu-devel] [PATCH 7/8] rng-egd: introduce EGD compliant RNG backend

[Amit Shah]

From: Anthony Liguori <aliguori@us.ibm.com>

This backend talks EGD to a CharDriverState.  A typical way to invoke this would
be:

qemu -chardev socket,host=localhost,port=1024,id=chr0 \
     -object rng-egd,chardev=chr0,id=egd0 \
     -device virtio-rng-pci,rng=egd0

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
 backends/Makefile.objs |    2 +-
 backends/rng-egd.c     |  215 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 216 insertions(+), 1 deletions(-)
 create mode 100644 backends/rng-egd.c

diff --git a/backends/Makefile.objs b/backends/Makefile.objs
index 423c9df..937e30a 100644
--- a/backends/Makefile.objs
+++ b/backends/Makefile.objs
@@ -1 +1 @@
-common-obj-y += rng.o rng-urandom.o
+common-obj-y += rng.o rng-urandom.o rng-egd.o
diff --git a/backends/rng-egd.c b/backends/rng-egd.c
new file mode 100644
index 0000000..7c459dc
--- /dev/null
+++ b/backends/rng-egd.c
@@ -0,0 +1,215 @@
+/*
+ * QEMU Random Number Generator Backend
+ *
+ * Copyright IBM, Corp. 2012
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/rng.h"
+#include "qemu-char.h"
+#include "qerror.h"
+#include "hw/qdev.h" // just for DEFINE_PROP_CHR
+
+#define TYPE_RNG_EGD "rng-egd"
+#define RNG_EGD(obj) OBJECT_CHECK(RngEgd, (obj), TYPE_RNG_EGD)
+
+typedef struct RngEgd
+{
+    RngBackend parent;
+
+    CharDriverState *chr;
+    char *chr_name;
+
+    GSList *requests;
+} RngEgd;
+
+typedef struct RngRequest
+{
+    EntropyReceiveFunc *receive_entropy;
+    uint8_t *data;
+    void *opaque;
+    size_t offset;
+    size_t size;
+} RngRequest;
+
+static void rng_egd_request_entropy(RngBackend *b, size_t size,
+                                    EntropyReceiveFunc *receive_entropy,
+                                    void *opaque)
+{
+    RngEgd *s = RNG_EGD(b);
+    RngRequest *req;
+
+    req = g_malloc(sizeof(*req));
+
+    req->offset = 0;
+    req->size = size;
+    req->receive_entropy = receive_entropy;
+    req->opaque = opaque;
+    req->data = g_malloc(req->size);
+
+    while (size > 0) {
+        uint8_t header[2];
+        uint8_t len = MIN(size, 255);
+
+        /* synchronous entropy request */
+        header[0] = 0x02;
+        header[1] = len;
+
+        qemu_chr_fe_write(s->chr, header, sizeof(header));
+
+        size -= len;
+    }
+
+    s->requests = g_slist_append(s->requests, req);
+}
+
+static void rng_egd_free_request(RngRequest *req)
+{
+    g_free(req->data);
+    g_free(req);
+}
+
+static int rng_egd_chr_can_read(void *opaque)
+{
+    RngEgd *s = RNG_EGD(opaque);
+    GSList *i;
+    int size = 0;
+
+    for (i = s->requests; i; i = i->next) {
+        RngRequest *req = i->data;
+        size += req->size - req->offset;
+    }
+
+    return size;
+}
+
+static void rng_egd_chr_read(void *opaque, const uint8_t *buf, int size)
+{
+    RngEgd *s = RNG_EGD(opaque);
+
+    while (size > 0 && s->requests) {
+        RngRequest *req = s->requests->data;
+        int len = MIN(size, req->size - req->offset);
+
+        memcpy(req->data + req->offset, buf, len);
+        req->offset += len;
+        size -= len;
+
+        if (req->offset == req->size) {
+            s->requests = g_slist_remove_link(s->requests, s->requests);
+
+            req->receive_entropy(req->opaque, req->data, req->size);
+
+            rng_egd_free_request(req);
+        }
+    }
+}
+
+static void rng_egd_cancel_requests(RngBackend *b)
+{
+    RngEgd *s = RNG_EGD(b);
+
+    /* We simply delete the list of pending requests.  If there is data in the 
+     * queue waiting to be read, this is okay, because there will always be
+     * more data than we requested originally
+     */
+    g_slist_free_full(s->requests,
+                      (GDestroyNotify)rng_egd_free_request);
+    s->requests = NULL;
+}
+
+static void rng_egd_opened(RngBackend *b, Error **errp)
+{
+    RngEgd *s = RNG_EGD(b);
+
+    if (s->chr_name == NULL) {
+        error_set(errp, QERR_INVALID_PARAMETER_VALUE,
+                  "chardev", "a valid character device");
+        return;
+    }
+
+    s->chr = qemu_chr_find(s->chr_name);
+    if (s->chr == NULL) {
+        error_set(errp, QERR_DEVICE_NOT_FOUND, s->chr_name);
+        return;
+    }
+
+    /* FIXME we should resubmit pending requests when the CDS reconnects. */
+    qemu_chr_add_handlers(s->chr, rng_egd_chr_can_read, rng_egd_chr_read,
+                          NULL, s);
+}
+
+static void rng_egd_set_chardev(Object *obj, const char *value, Error **errp)
+{
+    RngBackend *b = RNG_BACKEND(obj);
+    RngEgd *s = RNG_EGD(b);
+
+    if (b->opened) {
+        error_set(errp, QERR_PERMISSION_DENIED);
+    } else {
+        g_free(s->chr_name);
+        s->chr_name = g_strdup(value);
+    }
+}
+
+static char *rng_egd_get_chardev(Object *obj, Error **errp)
+{
+    RngEgd *s = RNG_EGD(obj);
+
+    if (s->chr && s->chr->label) {
+        return g_strdup(s->chr->label);
+    }
+
+    return NULL;
+}
+
+static void rng_egd_init(Object *obj)
+{
+    object_property_add_str(obj, "chardev",
+                            rng_egd_get_chardev, rng_egd_set_chardev,
+                            NULL);
+}
+
+static void rng_egd_finalize(Object *obj)
+{
+    RngEgd *s = RNG_EGD(obj);
+
+    if (s->chr) {
+        qemu_chr_add_handlers(s->chr, NULL, NULL, NULL, NULL);
+    }
+
+    g_free(s->chr_name);
+
+    g_slist_free_full(s->requests, (GDestroyNotify)rng_egd_free_request);
+    s->requests = NULL;
+}
+
+static void rng_egd_class_init(ObjectClass *klass, void *data)
+{
+    RngBackendClass *rbc = RNG_BACKEND_CLASS(klass);
+
+    rbc->request_entropy = rng_egd_request_entropy;
+    rbc->cancel_requests = rng_egd_cancel_requests;
+    rbc->opened = rng_egd_opened;
+}
+
+static TypeInfo rng_egd_info = {
+    .name = TYPE_RNG_EGD,
+    .parent = TYPE_RNG_BACKEND,
+    .instance_size = sizeof(RngEgd),
+    .class_init = rng_egd_class_init,
+    .instance_init = rng_egd_init,
+    .instance_finalize = rng_egd_finalize,
+};
+
+static void register_types(void)
+{
+    type_register_static(&rng_egd_info);
+}
+
+type_init(register_types);
-- 
1.7.7.6

[Qemu-devel] [PATCH 8/8] virtio-rng: hardware random number generator device

[Amit Shah]

The Linux kernel already has a virtio-rng driver, this is the device
implementation.

When the guest asks for entropy from the virtio hwrng, it puts a buffer
in the vq.  We then put entropy into that buffer, and push it back to
the guest.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
 hw/Makefile.objs     |    1 +
 hw/pci.h             |    1 +
 hw/s390-virtio-bus.c |   37 ++++++++++++
 hw/s390-virtio-bus.h |    2 +
 hw/virtio-pci.c      |   60 ++++++++++++++++++++
 hw/virtio-pci.h      |    2 +
 hw/virtio-rng.c      |  149 ++++++++++++++++++++++++++++++++++++++++++++++++++
 hw/virtio-rng.h      |   24 ++++++++
 hw/virtio.h          |    3 +
 9 files changed, 279 insertions(+), 0 deletions(-)
 create mode 100644 hw/virtio-rng.c
 create mode 100644 hw/virtio-rng.h

diff --git a/hw/Makefile.objs b/hw/Makefile.objs
index af4ab0c..ea46f81 100644
--- a/hw/Makefile.objs
+++ b/hw/Makefile.objs
@@ -1,6 +1,7 @@
 common-obj-y = usb/ ide/
 common-obj-y += loader.o
 common-obj-$(CONFIG_VIRTIO) += virtio-console.o
+common-obj-$(CONFIG_VIRTIO) += virtio-rng.o
 common-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
 common-obj-y += fw_cfg.o
 common-obj-$(CONFIG_PCI) += pci.o pci_bridge.o pci_bridge_dev.o
diff --git a/hw/pci.h b/hw/pci.h
index 1f902f5..93e2a46 100644
--- a/hw/pci.h
+++ b/hw/pci.h
@@ -76,6 +76,7 @@
 #define PCI_DEVICE_ID_VIRTIO_BALLOON     0x1002
 #define PCI_DEVICE_ID_VIRTIO_CONSOLE     0x1003
 #define PCI_DEVICE_ID_VIRTIO_SCSI        0x1004
+#define PCI_DEVICE_ID_VIRTIO_RNG         0x1005
 
 #define FMT_PCIBUS                      PRIx64
 
diff --git a/hw/s390-virtio-bus.c b/hw/s390-virtio-bus.c
index 5849a96..e0ac2d1 100644
--- a/hw/s390-virtio-bus.c
+++ b/hw/s390-virtio-bus.c
@@ -26,6 +26,7 @@
 #include "loader.h"
 #include "elf.h"
 #include "hw/virtio.h"
+#include "hw/virtio-rng.h"
 #include "hw/virtio-serial.h"
 #include "hw/virtio-net.h"
 #include "hw/sysbus.h"
@@ -206,6 +207,18 @@ static int s390_virtio_scsi_init(VirtIOS390Device *dev)
     return s390_virtio_device_init(dev, vdev);
 }
 
+static int s390_virtio_rng_init(VirtIOS390Device *dev)
+{
+    VirtIODevice *vdev;
+
+    vdev = virtio_rng_init((DeviceState *)dev, &dev->rng);
+    if (!vdev) {
+        return -1;
+    }
+
+    return s390_virtio_device_init(dev, vdev);
+}
+
 static uint64_t s390_virtio_device_vq_token(VirtIOS390Device *dev, int vq)
 {
     ram_addr_t token_off;
@@ -448,6 +461,29 @@ static TypeInfo s390_virtio_serial = {
     .class_init    = s390_virtio_serial_class_init,
 };
 
+static void s390_virtio_rng_initfn(Object *obj)
+{
+    VirtIOS390Device *dev = VIRTIO_S390_DEVICE(obj);
+
+    object_property_add_link(obj, "rng", TYPE_RNG_BACKEND,
+                             (Object **)&dev->rng.rng, NULL);
+}
+
+static void s390_virtio_rng_class_init(ObjectClass *klass, void *data)
+{
+    VirtIOS390DeviceClass *k = VIRTIO_S390_DEVICE_CLASS(klass);
+
+    k->init = s390_virtio_rng_init;
+}
+
+static TypeInfo s390_virtio_rng = {
+    .name          = "virtio-rng-s390",
+    .parent        = TYPE_VIRTIO_S390_DEVICE,
+    .instance_size = sizeof(VirtIOS390Device),
+    .instance_init = s390_virtio_rng_initfn,
+    .class_init    = s390_virtio_rng_class_init,
+};
+
 static int s390_virtio_busdev_init(DeviceState *dev)
 {
     VirtIOS390Device *_dev = (VirtIOS390Device *)dev;
@@ -528,6 +564,7 @@ static void s390_virtio_register_types(void)
     type_register_static(&s390_virtio_blk);
     type_register_static(&s390_virtio_net);
     type_register_static(&s390_virtio_scsi);
+    type_register_static(&s390_virtio_rng);
     type_register_static(&s390_virtio_bridge_info);
 }
 
diff --git a/hw/s390-virtio-bus.h b/hw/s390-virtio-bus.h
index 4873134..a83afe7 100644
--- a/hw/s390-virtio-bus.h
+++ b/hw/s390-virtio-bus.h
@@ -19,6 +19,7 @@
 
 #include "virtio-blk.h"
 #include "virtio-net.h"
+#include "virtio-rng.h"
 #include "virtio-serial.h"
 #include "virtio-scsi.h"
 
@@ -75,6 +76,7 @@ struct VirtIOS390Device {
     virtio_serial_conf serial;
     virtio_net_conf net;
     VirtIOSCSIConf scsi;
+    VirtIORNGConf rng;
 };
 
 typedef struct VirtIOS390Bus {
diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index c7f20c3..0dc2a06 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -880,6 +880,28 @@ static void virtio_balloon_exit_pci(PCIDevice *pci_dev)
     virtio_exit_pci(pci_dev);
 }
 
+static int virtio_rng_init_pci(PCIDevice *pci_dev)
+{
+    VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
+    VirtIODevice *vdev;
+
+    vdev = virtio_rng_init(&pci_dev->qdev, &proxy->rng);
+    if (!vdev) {
+        return -1;
+    }
+    virtio_init_pci(proxy, vdev);
+    return 0;
+}
+
+static void virtio_rng_exit_pci(PCIDevice *pci_dev)
+{
+    VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
+
+    virtio_pci_stop_ioeventfd(proxy);
+    virtio_rng_exit(proxy->vdev);
+    virtio_exit_pci(pci_dev);
+}
+
 static Property virtio_blk_properties[] = {
     DEFINE_PROP_HEX32("class", VirtIOPCIProxy, class_code, 0),
     DEFINE_BLOCK_PROPERTIES(VirtIOPCIProxy, blk.conf),
@@ -1010,6 +1032,43 @@ static TypeInfo virtio_balloon_info = {
     .class_init    = virtio_balloon_class_init,
 };
 
+static void virtio_rng_initfn(Object *obj)
+{
+    PCIDevice *pci_dev = PCI_DEVICE(obj);
+    VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
+
+    object_property_add_link(obj, "rng", TYPE_RNG_BACKEND,
+                             (Object **)&proxy->rng.rng, NULL);
+}
+
+static Property virtio_rng_properties[] = {
+    DEFINE_VIRTIO_COMMON_FEATURES(VirtIOPCIProxy, host_features),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void virtio_rng_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
+
+    k->init = virtio_rng_init_pci;
+    k->exit = virtio_rng_exit_pci;
+    k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
+    k->device_id = PCI_DEVICE_ID_VIRTIO_RNG;
+    k->revision = VIRTIO_PCI_ABI_VERSION;
+    k->class_id = PCI_CLASS_OTHERS;
+    dc->reset = virtio_pci_reset;
+    dc->props = virtio_rng_properties;
+}
+
+static TypeInfo virtio_rng_info = {
+    .name          = "virtio-rng-pci",
+    .parent        = TYPE_PCI_DEVICE,
+    .instance_size = sizeof(VirtIOPCIProxy),
+    .instance_init = virtio_rng_initfn,
+    .class_init    = virtio_rng_class_init,
+};
+
 static int virtio_scsi_init_pci(PCIDevice *pci_dev)
 {
     VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
@@ -1074,6 +1133,7 @@ static void virtio_pci_register_types(void)
     type_register_static(&virtio_serial_info);
     type_register_static(&virtio_balloon_info);
     type_register_static(&virtio_scsi_info);
+    type_register_static(&virtio_rng_info);
 }
 
 type_init(virtio_pci_register_types)
diff --git a/hw/virtio-pci.h b/hw/virtio-pci.h
index ac9d522..b58d9a2 100644
--- a/hw/virtio-pci.h
+++ b/hw/virtio-pci.h
@@ -17,6 +17,7 @@
 
 #include "virtio-blk.h"
 #include "virtio-net.h"
+#include "virtio-rng.h"
 #include "virtio-serial.h"
 #include "virtio-scsi.h"
 
@@ -46,6 +47,7 @@ typedef struct {
     virtio_serial_conf serial;
     virtio_net_conf net;
     VirtIOSCSIConf scsi;
+    VirtIORNGConf rng;
     bool ioeventfd_disabled;
     bool ioeventfd_started;
     VirtIOIRQFD *vector_irqfd;
diff --git a/hw/virtio-rng.c b/hw/virtio-rng.c
new file mode 100644
index 0000000..290b2b6
--- /dev/null
+++ b/hw/virtio-rng.c
@@ -0,0 +1,149 @@
+/*
+ * A virtio device implementing a hardware random number generator.
+ *
+ * Copyright 2012 Red Hat, Inc.
+ * Copyright 2012 Amit Shah <amit.shah@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * (at your option) any later version.  See the COPYING file in the
+ * top-level directory.
+ */
+
+#include "iov.h"
+#include "qdev.h"
+#include "virtio.h"
+#include "virtio-rng.h"
+#include "qemu/rng.h"
+
+typedef struct VirtIORNG {
+    VirtIODevice vdev;
+
+    DeviceState *qdev;
+
+    /* Only one vq - guest puts buffer(s) on it when it needs entropy */
+    VirtQueue *vq;
+
+    VirtIORNGConf *conf;
+
+    RngBackend *rng;
+} VirtIORNG;
+
+static bool is_guest_ready(VirtIORNG *vrng)
+{
+    if (virtio_queue_ready(vrng->vq)
+        && (vrng->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
+        return true;
+    }
+    return false;
+}
+
+static size_t get_request_size(VirtQueue *vq)
+{
+    unsigned int in, out;
+
+    virtqueue_get_avail_bytes(vq, &in, &out);
+    return in;
+}
+
+/* Send data from a char device over to the guest */
+static void chr_read(void *opaque, const void *buf, size_t size)
+{
+    VirtIORNG *vrng = opaque;
+    VirtQueueElement elem;
+    size_t len;
+    int offset;
+
+    if (!is_guest_ready(vrng)) {
+        return;
+    }
+
+    offset = 0;
+    while (offset < size) {
+        if (!virtqueue_pop(vrng->vq, &elem)) {
+            break;
+        }
+        len = iov_from_buf(elem.in_sg, elem.in_num,
+                           0, buf + offset, size - offset);
+        offset += len;
+
+        virtqueue_push(vrng->vq, &elem, len);
+    }
+    virtio_notify(&vrng->vdev, vrng->vq);
+}
+
+static void handle_input(VirtIODevice *vdev, VirtQueue *vq)
+{
+    VirtIORNG *vrng = DO_UPCAST(VirtIORNG, vdev, vdev);
+    size_t size;
+
+    size = get_request_size(vq);
+    if (size) {
+        rng_backend_request_entropy(vrng->rng, size, chr_read, vrng);
+    }
+}
+
+static uint32_t get_features(VirtIODevice *vdev, uint32_t f)
+{
+    return f;
+}
+
+static void virtio_rng_save(QEMUFile *f, void *opaque)
+{
+    VirtIORNG *vrng = opaque;
+
+    virtio_save(&vrng->vdev, f);
+}
+
+static int virtio_rng_load(QEMUFile *f, void *opaque, int version_id)
+{
+    VirtIORNG *vrng = opaque;
+
+    if (version_id != 1) {
+        return -EINVAL;
+    }
+    virtio_load(&vrng->vdev, f);
+    return 0;
+}
+
+VirtIODevice *virtio_rng_init(DeviceState *dev, VirtIORNGConf *conf)
+{
+    VirtIORNG *vrng;
+    VirtIODevice *vdev;
+    Error *local_err = NULL;
+
+    vdev = virtio_common_init("virtio-rng", VIRTIO_ID_RNG, 0,
+                              sizeof(VirtIORNG));
+
+    vrng = DO_UPCAST(VirtIORNG, vdev, vdev);
+
+    vrng->rng = conf->rng;
+    if (vrng->rng == NULL) {
+        qerror_report(QERR_INVALID_PARAMETER_VALUE, "rng", "a valid object");
+        return NULL;
+    }
+
+    rng_backend_open(vrng->rng, &local_err);
+    if (local_err) {
+        qerror_report_err(local_err);
+        error_free(local_err);
+        return NULL;
+    }
+
+    vrng->vq = virtio_add_queue(vdev, 8, handle_input);
+    vrng->vdev.get_features = get_features;
+
+    vrng->qdev = dev;
+    vrng->conf = conf;
+    register_savevm(dev, "virtio-rng", -1, 1, virtio_rng_save,
+                    virtio_rng_load, vrng);
+
+    return vdev;
+}
+
+void virtio_rng_exit(VirtIODevice *vdev)
+{
+    VirtIORNG *vrng = DO_UPCAST(VirtIORNG, vdev, vdev);
+
+    unregister_savevm(vrng->qdev, "virtio-rng", vrng);
+    virtio_cleanup(vdev);
+}
diff --git a/hw/virtio-rng.h b/hw/virtio-rng.h
new file mode 100644
index 0000000..fbb0104
--- /dev/null
+++ b/hw/virtio-rng.h
@@ -0,0 +1,24 @@
+/*
+ * Virtio RNG Support
+ *
+ * Copyright Red Hat, Inc. 2012
+ * Copyright Amit Shah <amit.shah@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * (at your option) any later version.  See the COPYING file in the
+ * top-level directory.
+ */
+
+#ifndef _QEMU_VIRTIO_RNG_H
+#define _QEMU_VIRTIO_RNG_H
+
+#include "qemu/rng.h"
+
+/* The Virtio ID for the virtio rng device */
+#define VIRTIO_ID_RNG    4
+
+struct VirtIORNGConf {
+    RngBackend *rng;
+};
+
+#endif
diff --git a/hw/virtio.h b/hw/virtio.h
index ac482be..df8d0f7 100644
--- a/hw/virtio.h
+++ b/hw/virtio.h
@@ -203,6 +203,8 @@ VirtIODevice *virtio_serial_init(DeviceState *dev, virtio_serial_conf *serial);
 VirtIODevice *virtio_balloon_init(DeviceState *dev);
 typedef struct VirtIOSCSIConf VirtIOSCSIConf;
 VirtIODevice *virtio_scsi_init(DeviceState *dev, VirtIOSCSIConf *conf);
+typedef struct VirtIORNGConf VirtIORNGConf;
+VirtIODevice *virtio_rng_init(DeviceState *dev, VirtIORNGConf *conf);
 #ifdef CONFIG_LINUX
 VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf);
 #endif
@@ -213,6 +215,7 @@ void virtio_blk_exit(VirtIODevice *vdev);
 void virtio_serial_exit(VirtIODevice *vdev);
 void virtio_balloon_exit(VirtIODevice *vdev);
 void virtio_scsi_exit(VirtIODevice *vdev);
+void virtio_rng_exit(VirtIODevice *vdev);
 
 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \
 	DEFINE_PROP_BIT("indirect_desc", _state, _field, \
-- 
1.7.7.6

Re: [Qemu-devel] [PATCH 0/8] virtio-rng: hardware random number generator device

[Paolo Bonzini]

Il 26/10/2012 13:01, Amit Shah ha scritto:
> Amit Shah (1):
>   virtio-rng: hardware random number generator device
> 
> Anthony Liguori (7):
>   object: add object_property_add_bool (v2)
>   qdev: add realized property and make adding child bus implied by
>     realize
>   vl: add -object option to create QOM objects from the command line
>   vl: add -late-object to create QOM objects after machine init
>   rng: add RndBackend abstract object class
>   rng-urandom: add an RNG backend that uses /dev/urandom
>   rng-egd: introduce EGD compliant RNG backend

Honestly I think this is overengineered.

I would instead have the following:

- a chardev that can read from a file (e.g. -chardev
file,path=/dev/urandom,read=on,id=urandom)

- a device that accepts a chardev and understands both egd and raw (e.g.
-device virtio-rng-pci,chardev=urandom,egd=off or -device
virtio-rng-pci,chardev=egdsock,egd=on).

- optionally, a chardev that can produce an endless stream of data via
rdrand.

And that's it.

Also, even if RngBackend goes in, there is no need for -late-object
right now, so I would not include it in this series.

Paolo

Re: [Qemu-devel] [PATCH 0/8] virtio-rng: hardware random number generator device

[Anthony Liguori]

Paolo Bonzini <pbonzini@redhat.com> writes:

> Il 26/10/2012 13:01, Amit Shah ha scritto:
>> Amit Shah (1):
>>   virtio-rng: hardware random number generator device
>> 
>> Anthony Liguori (7):
>>   object: add object_property_add_bool (v2)
>>   qdev: add realized property and make adding child bus implied by
>>     realize
>>   vl: add -object option to create QOM objects from the command line
>>   vl: add -late-object to create QOM objects after machine init
>>   rng: add RndBackend abstract object class
>>   rng-urandom: add an RNG backend that uses /dev/urandom
>>   rng-egd: introduce EGD compliant RNG backend
>
> Honestly I think this is overengineered.
>
> I would instead have the following:
>
> - a chardev that can read from a file (e.g. -chardev
> file,path=/dev/urandom,read=on,id=urandom)

Then your multiplexing lots of logic into the chardev layer.

Three of these patches can be dropped.  See the series I sent out.

Regards,

Anthony Liguori

> - a device that accepts a chardev and understands both egd and raw
> (e.g.

> -device virtio-rng-pci,chardev=urandom,egd=off or -device
> virtio-rng-pci,chardev=egdsock,egd=on).
>
> - optionally, a chardev that can produce an endless stream of data via
> rdrand.
>
> And that's it.
>
> Also, even if RngBackend goes in, there is no need for -late-object
> right now, so I would not include it in this series.
>
> Paolo

Re: [Qemu-devel] [PATCH 0/8] virtio-rng: hardware random number generator device

[Paolo Bonzini]

Il 26/10/2012 17:14, Anthony Liguori ha scritto:
>> > I would instead have the following:
>> >
>> > - a chardev that can read from a file (e.g. -chardev
>> > file,path=/dev/urandom,read=on,id=urandom)
> Then your multiplexing lots of logic into the chardev layer.

Then call it -chardev filein,path=/dev/urandom,id=urandom. :)

> Three of these patches can be dropped.  See the series I sent out.

Same comments apply there...

Paolo

Re: [Qemu-devel] [PATCH 0/8] virtio-rng: hardware random number generator device

[Anthony Liguori]

Paolo Bonzini <pbonzini@redhat.com> writes:

> Il 26/10/2012 17:14, Anthony Liguori ha scritto:
>>> > I would instead have the following:
>>> >
>>> > - a chardev that can read from a file (e.g. -chardev
>>> > file,path=/dev/urandom,read=on,id=urandom)
>> Then your multiplexing lots of logic into the chardev layer.
>
> Then call it -chardev filein,path=/dev/urandom,id=urandom. :)

Let's move this to my thread please...

Regards,

Anthony Liguori

>
>> Three of these patches can be dropped.  See the series I sent out.
>
> Same comments apply there...
>
> Paolo