RHBA-2017:0115 - Bug Fix Advisory

Topic

Updated qemu-kvm-rhev packages that fix several bugs are now available for Red Hat Virtualization Hypervisor 7.

Description

KVM (Kernel-based Virtual Machine) is a full virtualization solution for Linux on AMD64 and Intel 64 systems. The qemu-kvm-rhev packages provide the user-space component for running virtual machines using KVM in environments managed by Red Hat Virtualization Manager.

This update fixes the following bugs:

• Attempting to migrate a Windows guest virtual machine that was using the virtio-net-pci device from a Red Hat Enterprise Linux (RHEL) 6 host to a RHEL 7.3 host previously caused the guest to terminate unexpectedly, because the ctrl_guest_offloads feature was disabled on the destination host. This update enables ctrl_guest_offloads on the destination host, and the described migration works as expected. (BZ#1392876)
• Previously, using the virt-viewer utility to view a guest virtual machine in virtual network computing (VNC) graphic mode did not properly generate the graphical output if virt-viewer was disconnected and then reconnected in a short span of time. With this update, a server refresh is reliably triggered on reconnecting with virt-viewer in the described scenario, and it shows the expected graphical output. (BZ#1392881)
• Due to asynchronous I/O control blocks (AIOCBs) not being properly cleared, guests that use the Advanced Host Controller Interface (AHCI) in some cases terminated unexpectedly when an I/O error occurred. With this update, AIOCB is cleared properly, and I/O errors on guests with AHCI are resolved gracefully. (BZ#1393736)
• Using post-copy migration with XOR-based zero run-length encoding (XBZRLE) compression previously caused the migration to fail and the guest to stay in a paused state. This update disables XBZRLE page compression for post-copy migration, and thus avoids the described problem. (BZ#1395360)
• Prior to this update, migrated guest virtual machines in some cases entered an inconsistent state and terminated unexpectedly after the migration finished due to incorrect handling of the virtqueue. With this update, virtqueue handling on migration is fixed, and no longer causes problems after guest migration. (BZ#1402509)
• This updates removes multiple memory leaks in the qemu-kvm service, and thus improves its security. (BZ#1397745)
• Using "Opteron" CPU options with Red Hat Enterprise Linux (RHEL) 6 machine types caused the QEMU emulator to terminate unexpectedly due to a typographical error in one of device names. This update corrects the error so "Opteron" CPU options can be used with RHEL 6 machine types as expected. (BZ#1408122)
• Hot plugging a vhostuser network device to a guest virtual machine caused the QEMU emulator to terminate unexpectedly due to access to an uninitialized chardev structure. The handling of vhostuser was improved not to access this structure if it is not initialized. As a result, the vhostuser network device can be hot plugged successfully. (BZ#1410200)

Users of qemu-kvm-rhev are advised to upgrade to these updated packages, which fix these bugs. After installing this update, shut down all running virtual machines. Once all virtual machines have shut down, start them again for this update to take effect.

Solution

Before applying this update, make sure all previously released errata relevant to your system have been applied.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Virtualization 4 for RHEL 7 x86_64
• Red Hat Virtualization 3 for RHEL 7 x86_64
• Red Hat Virtualization for IBM Power LE 4 for RHEL 7 ppc64le
• Red Hat Virtualization for IBM Power LE 3 ppc64le

Fixes

• BZ - 1392876 - windows guests migration from rhel6.8-z to rhel7.3 with virtio-net-pci fail
• BZ - 1392881 - Graphic can't be showed out quickly if guest graphic mode is vnc
• BZ - 1393736 - qemu core dump when there is an I/O error on AHCI
• BZ - 1395360 - Post-copy migration fails with XBZRLE compression
• BZ - 1397745 - Backport memory leak fixes from QEMU 2.7
• BZ - 1402509 - virtio-balloon stats virtqueue does not migrate properly
• BZ - 1408122 - Opteron_G4 CPU model broken in QEMU 2.6 with RHEL 6 machine type
• BZ - 1410200 - qemu gets SIGSEGV when hot-plug a vhostuser network

CVEs

(none)

References

(none)