Pkg xen devel - Mar 2014 - Bug#723656: bug 723656 - xen hvc0/ipmi console hangs

I have this happening in Ubuntu precise also. When I upgraded from 12.04.1 to
12.04.4 it looks like my ipmi/serial/hvc0 console stopped working and the last
message is: (XEN) Platform timer is 14.318MHz HPET

From /etc/default/grub:
GRUB_DEFAULT="Xen 4.1-amd64"
GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT=""
GRUB_CMDLINE_LINUX="console=tty1 console=hvc0 earlyprintk=xen"
GRUB_CMDLINE_XEN="loglvl=all guest_loglvl=all com1=115200,8n1,0x2f8,5
console=tty1,com1"


Package: xen-hypervisor-4.1-amd64        
State: installed
Automatically installed: no
Version: 4.1.5-0ubuntu0.12.04.3
Priority: optional
Section: universe/kernel
Maintainer: Ubuntu Developers <ubuntu-devel-discuss at lists.ubuntu.com>
Architecture: amd64
Uncompressed Size: 808 k
Recommends: xen-utils-4.1
Suggests: xen-docs-4.1
Provides: xen-hypervisor, xen-hypervisor-4.1, xen-hypervisor-amd64
Description: Xen Hypervisor on AMD64
 The hypervisor is the "core" for XEN itself.  It gets booted by the
boot loader and controls cpu
 and memory, sharing them between your administrative domain (Domain 0) and the
virtual guest
 systems. 
 
 In order to boot a XEN system along with this package you also need a kernel
specifically crafted
 to work as the Domain 0, mediating hardware access for XEN itself.