Security update for kvm (important)

This update for kvm fixes the following issues:

Security issues fixed:

• CVE-2015-7512: The receive packet size is now checked in the emulated
  pcnet driver, eliminating buffer overflow and potential security issue
  by malicious guest systems. (bsc#957162)
• CVE-2015-8345: A infinite loop in processing command block list was
  fixed that could be exploit by malicious guest systems (bsc#956829).

Other bugs fixed:

• To assist users past the migration incompatibility discussed in
  bsc#950590 (restore migration compatibility with SLE11 SP3 and SLE12, at
  the unfortunate expense to prior SLE11 SP4 kvm release compatability
  when a virtio-net device is used), print a message which references the
  support document TID 7017048. See
  <a href=“https://www.suse.com/support/kb/doc.php?id=7017048”>https://www.suse.com/support/kb/doc.php?id=7017048</a>
• Fix cases of wrong clock values in kvmclock timekeeping (bsc#947164 and
  bsc#953187)
• Enforce pxe rom sizes to ensure migration compatibility. (bsc#950590)
• Fix kvm live migration fails between sles11 sp3 and sp4 (bsc#950590)