Security update for xen (important)

This update for xen fixes several issues.

These security issues were fixed:

• CVE-2016-7092: The get_page_from_l3e function in arch/x86/mm.c in Xen
  allowed local 32-bit PV guest OS administrators to gain host OS
  privileges via vectors related to L3 recursive pagetables (bsc#995785)
• CVE-2016-7093: Xen allowed local HVM guest OS administrators to
  overwrite hypervisor memory and consequently gain host OS privileges by
  leveraging mishandling of instruction pointer truncation during
  emulation (bsc#995789)
• CVE-2016-7094: Buffer overflow in Xen allowed local x86 HVM guest OS
  administrators on guests running with shadow paging to cause a denial of
  service via a pagetable update (bsc#995792)
• CVE-2016-7154: Use-after-free vulnerability in the FIFO event channel
  code in Xen allowed local guest OS administrators to cause a denial of
  service (host crash) and possibly execute arbitrary code or obtain
  sensitive information via an invalid guest frame number (bsc#997731)
• CVE-2016-6836: VMWARE VMXNET3 NIC device allowed privileged user inside
  the guest to leak information. It occured while processing transmit(tx)
  queue, when it reaches the end of packet (bsc#994761)
• CVE-2016-6888: A integer overflow int the VMWARE VMXNET3 NIC device
  support, during the initialisation of new packets in the device, could
  have allowed a privileged user inside guest to crash the Qemu instance
  resulting in DoS (bsc#994772)
• CVE-2016-6833: A use-after-free issue in the VMWARE VMXNET3 NIC device
  support allowed privileged user inside guest to crash the Qemu instance
  resulting in DoS (bsc#994775)
• CVE-2016-6835: Buffer overflow in the VMWARE VMXNET3 NIC device support,
  causing an OOB read access (bsc#994625)
• CVE-2016-6834: A infinite loop during packet fragmentation in the VMWARE
  VMXNET3 NIC device support allowed privileged user inside guest to crash
  the Qemu instance resulting in DoS (bsc#994421)
• CVE-2016-6258: The PV pagetable code in arch/x86/mm.c in Xen allowed
  local 32-bit PV guest OS administrators to gain host OS privileges by
  leveraging fast-paths for updating pagetable entries (bsc#988675)

These non-security issues were fixed:

• bsc#993507: virsh detach-disk failing to detach disk
• bsc#991934: Xen hypervisor crash in csched_acct
• bsc#992224: During boot of Xen Hypervisor, Failed to get contiguous
  memory for DMA
• bsc#970135: New virtualization project clock test randomly fails on Xen
• bsc#994136: Unplug also SCSI disks in qemu-xen-traditional for upstream
  unplug protocol
• bsc#994136: xen_platform: unplug also SCSI disks in qemu-xen
• bsc#971949: xl: Support (by ignoring) xl migrate --live. xl migrations
  are always live
• bsc#990970: Add PMU support for Intel E7-8867 v4 (fam=6, model=79)
• bsc#966467: Live Migration SLES 11 SP3 to SP4 on AMD