There is snv_126 on the Mercurial repository at opensolaris.org.
xvm-gate 3.4 has also be taken to a new version: Xen 3.4.2-rc1-xvm (from 3.4.2-rc1-pre-xvm).
Sun Microsystems Inc. SunOS 5.11 snv_126 October 2009
bfu'ed from /export/home/pascal/archives-nightly-osol-nd/i386 on 2009-10-23
Sun Microsystems Inc. SunOS 5.11 snv_118 November 2008
pascal@priscilla:~$ uname -a
SunOS priscilla 5.11 snv_126 i86pc i386 i86xpv
xvm-gate 3.4 has also be taken to a new version: Xen 3.4.2-rc1-xvm (from 3.4.2-rc1-pre-xvm).
Sun Microsystems Inc. SunOS 5.11 snv_126 October 2009
bfu'ed from /export/home/pascal/archives-nightly-osol-nd/i386 on 2009-10-23
Sun Microsystems Inc. SunOS 5.11 snv_118 November 2008
pascal@priscilla:~$ uname -a
SunOS priscilla 5.11 snv_126 i86pc i386 i86xpv

How to install xen 3.4.2 in opensolaris 126????
You'll find the instructions on how to get the xen-3.4-testing tree from OpenSolaris.org here:
http://hub.opensolaris.org/bin/view/Project+xen-gate/BuildDevel
3.4-testing is the branch for Xen 3.4.2.
You'll need some packages in OpenSolaris to build the whole tree, especially the 16bit bcc-compiler suite (it is used to compile the real_mode x86 code for graphics and normal bios).
Do you have test this version in opensolaris 126 ????
Do you have tested this xvm's version in opensolaris 126?
My built 3.4.2-rc1 packages for Sun xVM can be found here:
http://southbrain.com/software/xvm/3.4.2-rc1-xvm/
This is the (non-debug) result of a build from Oct 6, 2009. I am not endorsed or in any other means paid or instructed by Sun Microsystems to release these binaries, use it ''AS-IS''. No warranty can be taken.
Pascal
Do you know what that means:
ov 7 22:38:04 opensolaris libvirtd: [ID 702911 user.error] 22:38:04.876: error : virLibConnError:399 : this function is not supported by the hypervisor: virConnectNumOfDefinedNetworks
Nov 7 22:38:04 opensolaris libvirtd: [ID 702911 user.error] 22:38:04.974: error : virXenErrorFunc:782 : this function is not supported by the hypervisor: xenHypervisorDomainBlockStats: block statistics not supported on this platform
And libvirtd eats all the RAM.
And does this xen version supports powerno ?
The version of libvirt does not match your Xen Hypervisor version.
Make sure that the right Xen hypervisor is loaded.