Created attachment 1082708 [details]
rhel6.7 have no kernel feature pae for CPU.png

Description of problem:
RHEL6.7x64 unable to boot due to kernel have no pae feature for CPU on xen host via remote rhel7 connection

Version-Release number of selected component (if applicable):
libvirt-1.2.17-13.el7.x86_64
qemu-kvm-1.5.3-104.el7.x86_64
virt-manager-1.2.1-8.el7.noarch
Host:RHEL-7.2-20151008.0

How reproducible:
100%

Steps to Reproduce:
1. Ensure xen server could be access
2. Run virt-manager. Add a new connect to xen host by clicking "File->Add Connection", select "Xen" in Hypervisor, check the "Connect to remote host" and input the hostname, then click "Connect".
3. Create a new guest by clicking the "Create a new virtual machine" icon and select "Local install media(ISO or CDROM)" then click forward and select rhel6.7x64.iso, then keep all the settings default until finish.
4.Enter into installation interface and click option "Install or upgrade an existing system", then prompt "this kernel requires the following feature not present on the CPU: pae, unable to boot", please refer to screenshot "rhel6.7 have no kernel feature pae for CPU.png"
5.Check the dumpxml for rhel6.7x64 guest which built on xen host via remote rhel7 connection as below, it really have no kernel feature "pae", please refer to guest xml "rhel6.7x64_on_xen_host_via_remote_rhel7_connection.xml", more details refer to virt-manager debug log "rhel6.7-x64-virt-manager-debug.log"
  <features>
    <acpi/>
    <apic/>
  </features>

Actual results:
As description

Expected results:
RHEL6.7x64 could be installed normally on xen host via remote rhel7 connection

Additional info:
1.If install rhel6.7-x64 on guest in xen virt-manager diectly, it could be installed normally and kernel have pae feature for CPU in xml, please refer to guest xml "rhel6.7x64_on_xen.xml"

  <features>
    <acpi/>
    <apic/>
    <pae/>
  </features>