This patch documments XML elements used for (basic) support of virtual RNG devices. In the devices section in the domain XML users may specify: For the default 'random' backend: <devices> <rng model='virtio'> <backend model='random'>/dev/urandom</backend> </rng> </devices> For the slightly more advanced EGD backend: <devices> <rng model='virtio'> <backend model='egd' type='udp'> <!-- this is a definition of a character device --> <source mode='bind' service='1234'/> <source mode='connect' host='1.2.3.4' service='1234'/> <!-- or other valid character device configuration --> </backend> </rng> </devices> For the planned random daemon/pool: <devices> <rng model='virtio'> <backend model='pool' pool='poolname'>class</backend> </devices> to enable the RNG device for guests. --- docs/formatdomain.html.in | 69 +++++++++++++++++++++++++++++++++++++++++++ docs/schemas/domaincommon.rng | 32 ++++++++++++++++++++ 2 files changed, 101 insertions(+) diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index ffcc33e..e8cd086 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -4278,6 +4278,75 @@ qemu-kvm -net nic,model=? /dev/null </ul> </dd> </dl> + <h4><a name="elementsRng">Random number generator device</a></h4> + + <p> + The virtual random number generator device allows the host to pass + through entropy to guest operating systems. + <span class="since">Since 1.0.3</span> + </p> + + <p> + Example: usage of the RNG device: + </p> +<pre> + ... + &lt;devices&gt; + &lt;rng model='virtio'&gt; + &lt;backend model='random'&gt;/dev/random&lt;/backend&gt; + &lt;!-- OR --&gt; + &lt;backend model='egd' type='udp'&gt; + &lt;source mode='bind' service='1234'&gt; + &lt;source mode='connect' host='1.2.3.4' service='1234'&gt; + &lt;/backend&gt; + &lt;/rng&gt; + &lt;/devices&gt; + ... +</pre> + <dl> + <dt><code>model</code></dt> + <dd> + <p> + The required <code>model</code> attribute specifies what type + of RNG device is provided. Valid values are specific to + the virtualization platform: + </p> + <ul> + <li>'virtio' &mdash; supported by qemu and virtio-rng kernel module</li> + </ul> + </dd> + <dt><code>backend</code></dt> + <dd> + <p> + The <code>backend</code> element specifies the source of entropy + to be used for the doimain. The source model is configured using the + <code>model</code> attribute. Supported source models are: + </p> + <ul> + <li>'random' &mdash; /dev/random (default) or similar device as source</li> + <li>'egd' &mdash; a EGD protocol backend. </li> + </ul> + </dd> + <dt><code>backend type='random'</code></dt> + <dd> + <p> + This backend type expects a non-blocking character device as input. + Examples of such devices are /dev/random and /dev/urandom. The file + name is specified as contents of the <code>backend</code> element. + When no file name is specified the hypervisor default is used. + </p> + </dd> + <dt><code>backend type='egd'</code></dt> + <dd> + <p> + This backend connects to a source using the EGD protocol. + The source is specified as a character device. Refer to + <a href='#elementsCharHostInterface'>character device host interface</a> + for more information. + </p> + </dd> + + </dl> <h3><a name="seclabel">Security label</a></h3> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index 63be4aa..8330a50 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -3126,6 +3126,7 @@ <ref name="hub"/> <ref name="redirdev"/> <ref name="redirfilter"/> + <ref name="rng"/> </choice> </zeroOrMore> <optional> @@ -3514,6 +3515,37 @@ </element> </define> + <define name="rng"> + <element name="rng"> + <attribute name="model"> + <choice> + <value>virtio</value> + </choice> + </attribute> + <ref name="rng-backend"/> + </element> + </define> + + <define name="rng-backend"> + <element name="backend"> + <choice> + <group> + <attribute name="model"> + <value>random</value> + </attribute> + <ref name="filePath"/> + </group> + <group> + <attribute name="model"> + <value>egd</value> + </attribute> + <ref name="qemucdevSrcType"/> + <ref name="qemucdevSrcDef"/> + </group> + </choice> + </element> + </define> + <define name="usbmaster"> <element name="master"> <attribute name="startport"> -- 1.8.1.1

This patch adds basic configuration support for the RNG device suporting the virtio model with the "random" and "egd" backend types as described in the schema in the previous patch. --- src/conf/domain_conf.c | 196 ++++++++++++++++++++++++++++++++++++++++++++++- src/conf/domain_conf.h | 37 +++++++++ src/libvirt_private.syms | 2 + 3 files changed, 234 insertions(+), 1 deletion(-) diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 7a2b012..a16d70b 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -175,7 +175,8 @@ VIR_ENUM_IMPL(virDomainDevice, VIR_DOMAIN_DEVICE_LAST, "redirdev", "smartcard", "chr", - "memballoon") + "memballoon", + "rng") VIR_ENUM_IMPL(virDomainDeviceAddress, VIR_DOMAIN_DEVICE_ADDRESS_TYPE_LAST, "none", @@ -700,6 +701,15 @@ VIR_ENUM_IMPL(virDomainNumatuneMemPlacementMode, "static", "auto"); +VIR_ENUM_IMPL(virDomainRNGModel, + VIR_DOMAIN_RNG_MODEL_LAST, + "virtio"); + +VIR_ENUM_IMPL(virDomainRNGBackend, + VIR_DOMAIN_RNG_BACKEND_LAST, + "random", + "egd"); + #define VIR_DOMAIN_XML_WRITE_FLAGS VIR_DOMAIN_XML_SECURE #define VIR_DOMAIN_XML_READ_FLAGS VIR_DOMAIN_XML_INACTIVE @@ -1597,6 +1607,9 @@ void virDomainDeviceDefFree(virDomainDeviceDefPtr def) case VIR_DOMAIN_DEVICE_REDIRDEV: virDomainRedirdevDefFree(def->data.redirdev); break; + case VIR_DOMAIN_DEVICE_RNG: + virDomainRNGDefFree(def->data.rng); + break; case VIR_DOMAIN_DEVICE_NONE: case VIR_DOMAIN_DEVICE_FS: case VIR_DOMAIN_DEVICE_SMARTCARD: @@ -7403,6 +7416,109 @@ error: } +static virDomainRNGDefPtr +virDomainRNGDefParseXML(const xmlNodePtr node, + xmlXPathContextPtr ctxt, + unsigned int flags) +{ + const char *model; + const char *backend; + virDomainRNGDefPtr def; + xmlNodePtr save = ctxt->node; + xmlNodePtr *backends = NULL; + int nbackends; + + if (VIR_ALLOC(def) < 0) { + virReportOOMError(); + return NULL; + } + + if (!(model = virXMLPropString(node, "model"))) { + virReportError(VIR_ERR_XML_ERROR, "%s", _("missing RNG device model")); + goto error; + } + + if ((def->model = virDomainRNGModelTypeFromString(model)) < 0) { + virReportError(VIR_ERR_XML_ERROR, _("unknown RNG model '%s'"), model); + goto error; + } + + ctxt->node = node; + + if ((nbackends = virXPathNodeSet("./backend", ctxt, &backends)) < 0) + goto error; + + if (nbackends != 1) { + virReportError(VIR_ERR_XML_ERROR, "%s", + _("only one RNG backend is supported")); + goto error; + } + + if (!(backend = virXMLPropString(backends[0], "model"))) { + virReportError(VIR_ERR_XML_ERROR, "%s", + _("missing RNG device backend model")); + goto error; + } + + if ((def->backend = virDomainRNGBackendTypeFromString(backend)) < 0) { + virReportError(VIR_ERR_XML_ERROR, + _("unknown RNG backend model '%s'"), backend); + goto error; + } + + switch ((enum virDomainRNGBackend) def->backend) { + case VIR_DOMAIN_RNG_BACKEND_RANDOM: + def->source.file = virXPathString("string(./backend)", ctxt); + break; + + case VIR_DOMAIN_RNG_BACKEND_EGD: + { + char *type = virXMLPropString(backends[0], "type"); + if (!type) { + virReportError(VIR_ERR_XML_ERROR, "%s", + _("missing EGD backend type")); + goto error; + } + + + if (VIR_ALLOC(def->source.chardev) < 0) { + virReportOOMError(); + goto error; + } + + def->source.chardev->type = virDomainChrTypeFromString(type); + if (def->source.chardev->type < 0) { + virReportError(VIR_ERR_XML_ERROR, + _("unknown backend type '%s' for egd"), + type); + goto error; + } + + if (virDomainChrSourceDefParseXML(def->source.chardev, + backends[0]->children, flags, + NULL, ctxt, NULL, 0) < 0) + goto error; + } + break; + + case VIR_DOMAIN_RNG_BACKEND_LAST: + break; + } + + if (virDomainDeviceInfoParseXML(node, NULL, &def->info, flags) < 0) + goto error; + +cleanup: + ctxt->node = save; + return def; + +error: + virDomainRNGDefFree(def); + def = NULL; + goto cleanup; +} + + static virDomainMemballoonDefPtr virDomainMemballoonDefParseXML(const xmlNodePtr node, unsigned int flags) @@ -8196,6 +8312,10 @@ virDomainDeviceDefPtr virDomainDeviceDefParse(virCapsPtr caps, dev->type = VIR_DOMAIN_DEVICE_REDIRDEV; if (!(dev->data.redirdev = virDomainRedirdevDefParseXML(node, NULL, flags))) goto error; + } else if (xmlStrEqual(node->name, BAD_CAST "rng")) { + dev->type = VIR_DOMAIN_DEVICE_RNG; + if (!(dev->data.rng = virDomainRNGDefParseXML(node, ctxt, flags))) + goto error; } else { virReportError(VIR_ERR_XML_ERROR, "%s", _("unknown device type")); @@ -10552,6 +10672,22 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps, } } + /* Parse the RNG device */ + if ((n = virXPathNodeSet("./devices/rng", ctxt, &nodes)) < 0) + goto error; + + if (n > 1) { + virReportError(VIR_ERR_XML_ERROR, "%s", + _("only a single memory balloon device is supported")); + goto error; + } + + if (n > 0) { + if (!(def->rng = virDomainRNGDefParseXML(nodes[0], ctxt, flags))) + goto error; + VIR_FREE(nodes); + } + /* analysis of the hub devices */ if ((n = virXPathNodeSet("./devices/hub", ctxt, &nodes)) < 0) { goto error; @@ -13614,6 +13750,61 @@ virDomainWatchdogDefFormat(virBufferPtr buf, } +static int +virDomainRNGDefFormat(virBufferPtr buf, + virDomainRNGDefPtr def, + unsigned int flags) +{ + const char *model = virDomainRNGModelTypeToString(def->model); + const char *backend = virDomainRNGBackendTypeToString(def->backend); + + virBufferAsprintf(buf, " <rng model='%s'>\n", model); + virBufferAsprintf(buf, " <backend model='%s'", backend); + + switch ((enum virDomainRNGBackend) def->backend) { + case VIR_DOMAIN_RNG_BACKEND_RANDOM: + if (def->source.file) + virBufferAsprintf(buf, ">%s</backend>\n", def->source.file); + else + virBufferAddLit(buf, "/>\n"); + + break; + + case VIR_DOMAIN_RNG_BACKEND_EGD: + virBufferAdjustIndent(buf, 2); + if (virDomainChrSourceDefFormat(buf, def->source.chardev, + false, flags) < 0) + return -1; + virBufferAdjustIndent(buf, -2); + virBufferAddLit(buf, " </backend>\n"); + + case VIR_DOMAIN_RNG_BACKEND_LAST: + break; + } + + virBufferAddLit(buf, " </rng>\n"); + + return 0; +} + +void +virDomainRNGDefFree(virDomainRNGDefPtr def) +{ + if (!def) + return; + + switch ((enum virDomainRNGBackend) def->backend) { + case VIR_DOMAIN_RNG_BACKEND_RANDOM: + VIR_FREE(def->source.file); + break; + case VIR_DOMAIN_RNG_BACKEND_EGD: + virDomainChrSourceDefFree(def->source.chardev); + break; + case VIR_DOMAIN_RNG_BACKEND_LAST: + break; + } +} + static void virDomainVideoAccelDefFormat(virBufferPtr buf, virDomainVideoAccelDefPtr def) @@ -14812,6 +15003,9 @@ virDomainDefFormatInternal(virDomainDefPtr def, if (def->memballoon) virDomainMemballoonDefFormat(buf, def->memballoon, flags); + if (def->rng) + virDomainRNGDefFormat(buf, def->rng, flags); + virBufferAddLit(buf, " </devices>\n"); virBufferAdjustIndent(buf, 2); diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index 9232ff9..b78a04c 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -114,6 +114,9 @@ typedef virDomainSnapshotObj *virDomainSnapshotObjPtr; typedef struct _virDomainSnapshotObjList virDomainSnapshotObjList; typedef virDomainSnapshotObjList *virDomainSnapshotObjListPtr; +typedef struct _virDomainRNGDef virDomainRNGDef; +typedef virDomainRNGDef *virDomainRNGDefPtr; + /* Flags for the 'type' field in virDomainDeviceDef */ typedef enum { VIR_DOMAIN_DEVICE_NONE = 0, @@ -133,6 +136,7 @@ typedef enum { VIR_DOMAIN_DEVICE_SMARTCARD, VIR_DOMAIN_DEVICE_CHR, VIR_DOMAIN_DEVICE_MEMBALLOON, + VIR_DOMAIN_DEVICE_RNG, VIR_DOMAIN_DEVICE_LAST } virDomainDeviceType; @@ -158,6 +162,7 @@ struct _virDomainDeviceDef { virDomainSmartcardDefPtr smartcard; virDomainChrDefPtr chr; virDomainMemballoonDefPtr memballoon; + virDomainRNGDefPtr rng; } data; }; @@ -1714,6 +1719,33 @@ struct _virBlkioDeviceWeight { unsigned int weight; }; +enum virDomainRNGModel { + VIR_DOMAIN_RNG_MODEL_VIRTIO, + + VIR_DOMAIN_RNG_MODEL_LAST +}; + +enum virDomainRNGBackend { + VIR_DOMAIN_RNG_BACKEND_RANDOM, + VIR_DOMAIN_RNG_BACKEND_EGD, + /* VIR_DOMAIN_RNG_BACKEND_POOL, */ + + VIR_DOMAIN_RNG_BACKEND_LAST +}; + +struct _virDomainRNGDef { + int model; + int backend; + + union { + char *file; /* file name for 'random' source */ + virDomainChrSourceDefPtr chardev; /* a char backend for + the EGD source */ + } source; + + virDomainDeviceInfo info; +}; + void virBlkioDeviceWeightArrayClear(virBlkioDeviceWeightPtr deviceWeights, int ndevices); @@ -1852,6 +1884,7 @@ struct _virDomainDef { virCPUDefPtr cpu; virSysinfoDefPtr sysinfo; virDomainRedirFilterDefPtr redirfilter; + virDomainRNGDefPtr rng; void *namespaceData; virDomainXMLNamespace ns; @@ -2062,6 +2095,8 @@ int virDomainEmulatorPinAdd(virDomainDefPtr def, int virDomainEmulatorPinDel(virDomainDefPtr def); +void virDomainRNGDefFree(virDomainRNGDefPtr def); + int virDomainDiskIndexByName(virDomainDefPtr def, const char *name, bool allow_ambiguous); const char *virDomainDiskPathByName(virDomainDefPtr, const char *name); @@ -2322,6 +2357,8 @@ VIR_ENUM_DECL(virDomainGraphicsSpiceMouseMode) VIR_ENUM_DECL(virDomainNumatuneMemMode) VIR_ENUM_DECL(virDomainNumatuneMemPlacementMode) VIR_ENUM_DECL(virDomainHyperv) +VIR_ENUM_DECL(virDomainRNGModel) +VIR_ENUM_DECL(virDomainRNGBackend) /* from libvirt.h */ VIR_ENUM_DECL(virDomainState) VIR_ENUM_DECL(virDomainNostateReason) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index b9d45a2..814e66f 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -498,6 +498,8 @@ virDomainPMSuspendedReasonTypeFromString; virDomainPMSuspendedReasonTypeToString; virDomainRedirdevBusTypeFromString; virDomainRedirdevBusTypeToString; +virDomainRNGBackendTypeToString; +virDomainRNGModelTypeToString; virDomainRunningReasonTypeFromString; virDomainRunningReasonTypeToString; virDomainSaveConfig; -- 1.8.1.1

--- src/conf/domain_conf.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index a16d70b..53c6b2f 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -11699,6 +11699,36 @@ cleanup: } +static bool +virDomainRNGDefCheckABIStability(virDomainRNGDefPtr src, + virDomainRNGDefPtr dst) +{ + if (!src && !dst) + return true; + + if (!src || !dst) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("Target domain RNG device count '%d' " + "does not match source count '%d'"), + src ? 1 : 0, dst ? 1 : 0); + return false; + } + + if (src->model != dst->model) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("Target RNG model '%s' does not match source '%s'"), + virDomainRNGModelTypeToString(dst->model), + virDomainRNGModelTypeToString(src->model)); + return false; + } + + if (!virDomainDeviceInfoCheckABIStability(&src->info, &dst->info)) + return false; + + return true; +} + + static bool virDomainHubDefCheckABIStability(virDomainHubDefPtr src, virDomainHubDefPtr dst) { @@ -12081,6 +12111,9 @@ bool virDomainDefCheckABIStability(virDomainDefPtr src, !virDomainMemballoonDefCheckABIStability(src->memballoon, dst->memballoon)) goto cleanup; + if (!virDomainRNGDefCheckABIStability(src->rng, dst->rng)) + goto cleanup; + identical = true; cleanup: -- 1.8.1.1

This patch implements support for the virtio-rng-pci device and the rng-random backend in qemu. Two capabilities bits are added to track support for those: QEMU_CAPS_DEVICE_VIRTIO_RNG - for the device support and QEMU_CAPS_OBJECT_RNG_RANDOM - for the backend support. qemu is invoked with these additional parameters if the device is enabled: -object rng-random,id=rng0,filename=/test/phile (to add the backend) -device virtio-rng-pci,rng=rng0,bus=pci.0,addr=0x4 (to add the device) --- src/qemu/qemu_capabilities.c | 5 ++- src/qemu/qemu_capabilities.h | 3 ++ src/qemu/qemu_command.c | 100 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 107 insertions(+), 1 deletion(-) diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index 4efe052..a316a56 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -205,7 +205,8 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST, "usb-serial", /* 125 */ "usb-net", "add-fd", - + "virtio-rng", + "rng-random", ); struct _virQEMUCaps { @@ -1354,6 +1355,8 @@ struct virQEMUCapsStringFlags virQEMUCapsObjectTypes[] = { { "vmware-svga", QEMU_CAPS_DEVICE_VMWARE_SVGA }, { "usb-serial", QEMU_CAPS_DEVICE_USB_SERIAL}, { "usb-net", QEMU_CAPS_DEVICE_USB_NET}, + { "virtio-rng-pci", QEMU_CAPS_DEVICE_VIRTIO_RNG }, + { "rng-random", QEMU_CAPS_OBJECT_RNG_RANDOM }, }; diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h index e69d558..ee0d0ca 100644 --- a/src/qemu/qemu_capabilities.h +++ b/src/qemu/qemu_capabilities.h @@ -166,6 +166,9 @@ enum virQEMUCapsFlags { QEMU_CAPS_DEVICE_USB_SERIAL = 125, /* -device usb-serial */ QEMU_CAPS_DEVICE_USB_NET = 126, /* -device usb-net */ QEMU_CAPS_ADD_FD = 127, /* -add-fd */ + QEMU_CAPS_DEVICE_VIRTIO_RNG = 128, /* virtio-rng device */ + QEMU_CAPS_OBJECT_RNG_RANDOM = 129, /* the rng-random backend for + virtio rng */ QEMU_CAPS_LAST, /* this must always be the last item */ }; diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 6c28123..7ffa6ab 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -787,6 +787,10 @@ qemuAssignDeviceAliases(virDomainDefPtr def, virQEMUCapsPtr qemuCaps) if (virAsprintf(&def->memballoon->info.alias, "balloon%d", 0) < 0) goto no_memory; } + if (def->rng) { + if (virAsprintf(&def->rng->info.alias, "rng%d", 0) < 0) + goto no_memory; + } return 0; @@ -1701,6 +1705,14 @@ qemuAssignDevicePCISlots(virDomainDefPtr def, goto error; } + /* VirtIO RNG */ + if (def->rng && + def->rng->model == VIR_DOMAIN_RNG_MODEL_VIRTIO && + def->rng->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE) { + if (qemuDomainPCIAddressSetNextAddr(addrs, &def->rng->info) < 0) + goto error; + } + /* A watchdog - skip IB700, it is not a PCI device */ if (def->watchdog && def->watchdog->model != VIR_DOMAIN_WATCHDOG_MODEL_IB700 && @@ -4206,6 +4218,84 @@ error: return NULL; } + +static int +qemuBuildRNGBackendArgs(virCommandPtr cmd, + virDomainRNGDefPtr dev, + virQEMUCapsPtr qemuCaps) +{ + virBuffer buf = VIR_BUFFER_INITIALIZER; + int ret = -1; + + switch ((enum virDomainRNGBackend) dev->backend) { + case VIR_DOMAIN_RNG_BACKEND_RANDOM: + if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_OBJECT_RNG_RANDOM)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("this qemu doesn't support the rng-random " + " backend")); + goto cleanup; + } + + virBufferAsprintf(&buf, "rng-random,id=%s", dev->info.alias); + if (dev->source.file) + virBufferAsprintf(&buf, ",filename=%s", dev->source.file); + + virCommandAddArg(cmd, "-object"); + virCommandAddArgBuffer(cmd, &buf); + break; + + case VIR_DOMAIN_RNG_BACKEND_EGD: + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("egd RNG backend not yet implemented")); + goto cleanup; + break; + + case VIR_DOMAIN_RNG_BACKEND_LAST: + break; + } + + ret = 0; + +cleanup: + virBufferFreeAndReset(&buf); + return ret; +} + + +static int +qemuBuildRNGDeviceArgs(virCommandPtr cmd, + virDomainRNGDefPtr dev, + virQEMUCapsPtr qemuCaps) +{ + virBuffer buf = VIR_BUFFER_INITIALIZER; + int ret = -1; + + if (dev->model != VIR_DOMAIN_RNG_MODEL_VIRTIO || + !virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_VIRTIO_RNG)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("RNG device type '%s' is not supported " + "by this of qemu"), + virDomainRNGModelTypeToString(dev->model)); + goto cleanup; + } + + virBufferAsprintf(&buf, "virtio-rng-pci,rng=%s", dev->info.alias); + + if (qemuBuildDeviceAddressStr(&buf, &dev->info, qemuCaps) < 0) + goto cleanup; + + virCommandAddArg(cmd, "-device"); + virCommandAddArgBuffer(cmd, &buf); + + ret = 0; + +cleanup: + virBufferFreeAndReset(&buf); + return ret; +} + + + static char *qemuBuildSmbiosBiosStr(virSysinfoDefPtr def) { virBuffer buf = VIR_BUFFER_INITIALIZER; @@ -7047,6 +7137,16 @@ qemuBuildCommandLine(virConnectPtr conn, } } + if (def->rng) { + /* add the RNG source backend */ + if (qemuBuildRNGBackendArgs(cmd, def->rng, qemuCaps) < 0) + goto error; + + /* add the device */ + if (qemuBuildRNGDeviceArgs(cmd, def->rng, qemuCaps) < 0) + goto error; + } + if (snapshot) virCommandAddArgList(cmd, "-loadvm", snapshot->def->name, NULL); -- 1.8.1.1

Qemu's implementation of virtio RNG supports rate limiting of the entropy used. This patch exposes the option to tune this fucntionality. This patch is based on qemu commit 904d6f588063fb5ad2b61998acdf1e73fb4 The rate limiting is exported in the XML as: <devices> ... <rng model='virtio'> <rate period='1234'>4321</rate> <backend model='random'/> </rng> ... --- docs/formatdomain.html.in | 9 +++++++++ docs/schemas/domaincommon.rng | 18 +++++++++++++++++- src/conf/domain_conf.c | 17 +++++++++++++++++ src/conf/domain_conf.h | 2 ++ src/qemu/qemu_command.c | 8 ++++++++ .../qemuxml2argv-virtio-rng-random.args | 2 +- .../qemuxml2argv-virtio-rng-random.xml | 1 + 7 files changed, 55 insertions(+), 2 deletions(-) diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index e8cd086..b264460 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -4293,6 +4293,7 @@ qemu-kvm -net nic,model=? /dev/null ... &lt;devices&gt; &lt;rng model='virtio'&gt; + &lt;rate period="2000"&gt;1234&lt;/rate&gt; &lt;backend model='random'&gt;/dev/random&lt;/backend&gt; &lt;!-- OR --&gt; &lt;backend model='egd' type='udp'&gt; @@ -4315,6 +4316,14 @@ qemu-kvm -net nic,model=? /dev/null <li>'virtio' &mdash; supported by qemu and virtio-rng kernel module</li> </ul> </dd> + <dt><code>rate</code></dt> + <dd> + <p> + The rate parameter allows to limit the rate that the entropy can be + read from the source. The value is in bits that the device is allowed + to read in the selected period. The default period is 1000ms or 1 second. + </p> + </dd> <dt><code>backend</code></dt> <dd> <p> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index 8330a50..da53095 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -3522,7 +3522,12 @@ <value>virtio</value> </choice> </attribute> - <ref name="rng-backend"/> + <interleave> + <ref name="rng-backend"/> + <optional> + <ref name="rng-rate"/> + </optional> + </interleave> </element> </define> @@ -3546,6 +3551,17 @@ </element> </define> + <define name="rng-rate"> + <element name="rate"> + <optional> + <attribute name="period"> + <ref name="positiveInteger"/> + </attribute> + </optional> + <ref name="positiveInteger"/> + </element> + </define> + <define name="usbmaster"> <element name="master"> <attribute name="startport"> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 53c6b2f..023e92c 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -7445,6 +7445,17 @@ virDomainRNGDefParseXML(const xmlNodePtr node, ctxt->node = node; + if (virXPathUInt("string(./rate)", ctxt, &def->rate) < -1) { + virReportError(VIR_ERR_XML_ERROR, "%s", _("invalid RNG rate value")); + goto error; + } + + if (def->rate > 0 && + virXPathUInt("string(./rate/@period)", ctxt, &def->period) < -1) { + virReportError(VIR_ERR_XML_ERROR, "%s", _("invalid RNG period value")); + goto error; + } + if ((nbackends = virXPathNodeSet("./backend", ctxt, &backends)) < 0) goto error; @@ -13792,6 +13803,12 @@ virDomainRNGDefFormat(virBufferPtr buf, const char *backend = virDomainRNGBackendTypeToString(def->backend); virBufferAsprintf(buf, " <rng model='%s'>\n", model); + if (def->rate) { + virBufferAddLit(buf, " <rate"); + if (def->period) + virBufferAsprintf(buf, " period='%u'", def->period); + virBufferAsprintf(buf, ">%u</rate>\n", def->rate); + } virBufferAsprintf(buf, " <backend model='%s'", backend); switch ((enum virDomainRNGBackend) def->backend) { diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index b78a04c..b34484c 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -1736,6 +1736,8 @@ enum virDomainRNGBackend { struct _virDomainRNGDef { int model; int backend; + unsigned int rate; + unsigned int period; union { char *file; /* file name for 'random' source */ diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index d3a9b70..14d8f6d 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -4297,6 +4297,14 @@ qemuBuildRNGDeviceArgs(virCommandPtr cmd, virBufferAsprintf(&buf, "virtio-rng-pci,rng=%s", dev->info.alias); + if (dev->rate > 0) { + virBufferAsprintf(&buf, ",max-bytes=%u", dev->rate); + if (dev->period) + virBufferAsprintf(&buf, ",period=%u", dev->period); + else + virBufferAddLit(&buf, ",period=1000"); + } + if (qemuBuildDeviceAddressStr(&buf, &dev->info, qemuCaps) < 0) goto cleanup; diff --git a/tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.args b/tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.args index 4611ae5..428804b 100644 --- a/tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.args +++ b/tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.args @@ -1 +1 @@ -LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test /usr/bin/qemu -S -M pc -m 214 -smp 1 -nographic -nodefaults -monitor unix:/tmp/test-monitor,server,nowait -no-acpi -boot c -usb -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3 -object rng-random,id=rng0,filename=/test/phile -device virtio-rng-pci,rng=rng0,bus=pci.0,addr=0x4 +LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test /usr/bin/qemu -S -M pc -m 214 -smp 1 -nographic -nodefaults -monitor unix:/tmp/test-monitor,server,nowait -no-acpi -boot c -usb -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3 -object rng-random,id=rng0,filename=/test/phile -device virtio-rng-pci,rng=rng0,max-bytes=1337,period=1234,bus=pci.0,addr=0x4 diff --git a/tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.xml b/tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.xml index ab1f38c..73e77cd 100644 --- a/tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.xml +++ b/tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.xml @@ -17,6 +17,7 @@ <controller type='usb' index='0'/> <memballoon model='virtio'/> <rng model='virtio'> + <rate period='1234'>1337</rate> <backend model='random'>/test/phile</backend> </rng> </devices> -- 1.8.1.1

On 02/19/13 14:21, John Ferlan wrote: qemu uses bits for it's configuration value. As the expected data rades are pretty low, I think bits can be used and potentially divided to larger values if needed. Peter