Marek Marczykowski-Górecki wrote:
Xen have feature of having device model in separate domain (called stub domain). Add a 'type' attribute to 'emulator' element to allow selecting such a configuration.
Or maybe 'mode', describing the mode in which the emulator runs: as a process or as a VM.
Emulator path is still used for qemu running in dom0 (if any). Libxl currently do not allow to select stubdomain path.
That seems to overload a single <emulator>. Would it be better to have multiple <emulators>? E.g. <emulator>/usr/lib/xen/bin/qemu-system-i386</emulator> <emulator mode='stubdomain'>/usr/lib/xen/bin/stubdom-dm</emulator>
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> ---
I think it would be good idea to introduce the same change to capabilities XML. The problem is I can't include domain_conf.h from capabilities.h, so probably that enum declaration needs to be moved to capabilities.h. Is it the right way? Or it should be done somehow different?
docs/formatdomain.html.in | 14 ++++++++++++++ docs/schemas/domaincommon.rng | 23 ++++++++++++++++++++++- src/conf/domain_conf.c | 36 ++++++++++++++++++++++++++++++++++-- src/conf/domain_conf.h | 9 +++++++++ src/libxl/libxl_conf.c | 17 +++++++++++++++++ 5 files changed, 96 insertions(+), 3 deletions(-)
diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index 38c42d5..4f539e2 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -1652,6 +1652,20 @@ The <a href="formatcaps.html">capabilities XML</a> specifies the recommended default emulator to use for each particular domain type / architecture combination. + + <span class="since">Since 1.2.13</span>, the <code>emulator</code> + element may contain <code>type</code> attribute. Possible values are: + <dl> + <dt><code>type='default'</code></dt> + <dd>Equivalent to not setting <code>type</code> attribute at all. + </dd> + + <dt><code>type='stubdom'</code></dt> + <dd>Launch emulator in stub domain (Xen only). The emulator path + still indicate which binary is used in dom0 - there is no control + which binary is used as a stub domain. + </dd> + </dl> </dd> </dl>
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index a4321f1..2a12073 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -2519,7 +2519,28 @@ --> <define name="emulator"> <element name="emulator"> - <ref name="absFilePath"/> + <choice> + <group> + <optional> + <attribute name="type"> + <choice> + <value>qemu</value> + <value>stubdom</value> + </choice> + </attribute> + </optional> + <ref name="absFilePath"/> + </group> + <group> + <attribute name="type"> + <choice> + <value>qemu</value> + <value>stubdom</value> + </choice> + </attribute> + <empty/> + </group> + </choice> </element> </define> <!-- diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 17b699a..c268091 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -741,6 +741,10 @@ VIR_ENUM_IMPL(virDomainDiskTray, VIR_DOMAIN_DISK_TRAY_LAST, "closed", "open");
+VIR_ENUM_IMPL(virDomainEmulatorType, VIR_DOMAIN_EMULATOR_TYPE_LAST, + "qemu", + "stubdom"); + VIR_ENUM_IMPL(virDomainRNGModel, VIR_DOMAIN_RNG_MODEL_LAST, "virtio"); @@ -13712,6 +13716,14 @@ virDomainDefParseXML(xmlDocPtr xml, }
def->emulator = virXPathString("string(./devices/emulator[1])", ctxt); + if ((tmp = virXPathString("string(./devices/emulator/@type)", ctxt))) { + def->emulator_type = virDomainEmulatorTypeTypeFromString(tmp); + VIR_FREE(tmp); + if (def->emulator_type < 0) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("Unknown emulator type '%s'"), tmp); + } + }
/* analysis of the disk devices */ if ((n = virXPathNodeSet("./devices/disk", ctxt, &nodes)) < 0) @@ -15690,6 +15702,14 @@ virDomainDefCheckABIStability(virDomainDefPtr src, goto error; }
+ if (src->emulator_type != dst->emulator_type) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("Target domain emulator type %s does not match source %s"), + virDomainEmulatorTypeTypeToString(dst->emulator_type), + virDomainEmulatorTypeTypeToString(src->emulator_type)); + goto error; + } + if (!virDomainDefFeaturesCheckABIStability(src, dst)) goto error;
@@ -19893,8 +19913,20 @@ virDomainDefFormatInternal(virDomainDefPtr def, virBufferAddLit(buf, "<devices>\n"); virBufferAdjustIndent(buf, 2);
- virBufferEscapeString(buf, "<emulator>%s</emulator>\n", - def->emulator); + if (def->emulator || + def->emulator_type != VIR_DOMAIN_EMULATOR_TYPE_DEFAULT) { + virBufferAddLit(buf, "<emulator"); + if (def->emulator_type != VIR_DOMAIN_EMULATOR_TYPE_DEFAULT) { + virBufferAsprintf(buf, " type='%s'", + virDomainEmulatorTypeTypeToString(def->emulator_type)); + } + if (!def->emulator) { + virBufferAddLit(buf, "/>\n"); + } else { + virBufferEscapeString(buf, ">%s</emulator>\n", + def->emulator); + } + }
for (n = 0; n < def->ndisks; n++) if (virDomainDiskDefFormat(buf, def->disks[n], flags) < 0) diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index 28c6920..38b9037 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -1918,6 +1918,13 @@ struct _virBlkioDevice { };
typedef enum { + VIR_DOMAIN_EMULATOR_TYPE_DEFAULT, + VIR_DOMAIN_EMULATOR_TYPE_STUBDOM, + + VIR_DOMAIN_EMULATOR_TYPE_LAST +} virDomainEmulatorType; + +typedef enum { VIR_DOMAIN_RNG_MODEL_VIRTIO,
VIR_DOMAIN_RNG_MODEL_LAST @@ -2083,6 +2090,7 @@ struct _virDomainDef {
virDomainOSDef os; char *emulator; + virDomainEmulatorType emulator_type; /* These three options are of type virTristateSwitch, * except VIR_DOMAIN_FEATURE_CAPABILITIES that is of type * virDomainCapabilitiesPolicy */ @@ -2841,6 +2849,7 @@ VIR_ENUM_DECL(virDomainGraphicsSpiceMouseMode) VIR_ENUM_DECL(virDomainGraphicsVNCSharePolicy) VIR_ENUM_DECL(virDomainHyperv) VIR_ENUM_DECL(virDomainKVM) +VIR_ENUM_DECL(virDomainEmulatorType) VIR_ENUM_DECL(virDomainRNGModel) VIR_ENUM_DECL(virDomainRNGBackend) VIR_ENUM_DECL(virDomainTPMModel) diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c index b1131ea..a84ce09 100644 --- a/src/libxl/libxl_conf.c +++ b/src/libxl/libxl_conf.c @@ -768,6 +768,23 @@ libxlMakeDomBuildInfo(virDomainDefPtr def, b_info->device_model_version = libxlDomainGetEmulatorType(def); }
+ /* In case of stubdom there will be two qemu instances: + * - in stubdom (libxl uses hardcoded path for this one), + * - in dom0 as a backend for stubdom (if needed).
Your comment here provoked my thinking above about supporting multiple <emulator>s. ISTM there should be an <emulator> device for each of these qemu instances.
+ * Emulator path control only the second one. It makes a perfect sense + * to use <emulator type='stubdom'/> (yes, without emulator path).
I'm not so sure. Maybe we should first add support in libxl for specifying a stubdomain emulator path. Regards, Jim
+ */ + if (def->emulator_type == VIR_DOMAIN_EMULATOR_TYPE_STUBDOM) + libxl_defbool_set(&b_info->device_model_stubdomain, 1); + + if (def->os.cmdline && def->os.cmdline[0]) { + b_info->extra_hvm = virStringSplit(def->os.cmdline, " ", 0); + if (b_info->extra_hvm == NULL) { + virReportOOMError(); + return -1; + } + } + if (def->nserials) { if (def->nserials > 1) { virReportError(VIR_ERR_CONFIG_UNSUPPORTED,