Comment 5 for bug 1127214

My Saucy dom0 is also affected by this. I wasn't able to get the dmesg in text but I attached a picture of it.

The problem seems to be this:

 ata1.00: qc timeout (cmd 0xec)
 ata1.00: failed to IDENTIFY (I/O error, err_mask=0x4)

Then the SATA link back down a on speed (6 -> 3 Gbps) and the same occurs over and over.

The same kernel boots just fine when outside of Xen.

System info:

$ lsb_release -rd
Description: Ubuntu 13.10
Release: 13.10

$ apt-cache policy linux-image-`uname -r` xen-hypervisor-4.3-amd64
linux-image-3.11.0-13-generic:
  Installed: 3.11.0-13.20
  Candidate: 3.11.0-13.20
  Version table:
 *** 3.11.0-13.20 0
        500 http://archive.ubuntu.com/ubuntu/ saucy-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu/ saucy-security/main amd64 Packages
        100 /var/lib/dpkg/status
xen-hypervisor-4.3-amd64:
  Installed: 4.3.0-1ubuntu1
  Candidate: 4.3.0-1ubuntu1
  Version table:
 *** 4.3.0-1ubuntu1 0
        500 http://archive.ubuntu.com/ubuntu/ saucy/universe amd64 Packages
        100 /var/lib/dpkg/status