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Bug Fix Advisory kvm bug fix update

Advisory: RHBA-2010:0419-1
Type: Bug Fix Advisory
Severity: N/A
Issued on: 2010-05-18
Last updated on: 2010-05-18
Affected Products: RHEL Desktop Multi OS (v. 5 client)
RHEL Virtualization (v. 5 server)

Details

Updated kvm packages that address several issues are now available.

KVM (Kernel-based Virtual Machine) is a full virtualization solution for
Linux on AMD64 and Intel 64 systems. KVM is a Linux kernel module built for
the standard Red Hat Enterprise Linux kernel. KVM can run multiple
unmodified, virtualized guest Windows and Linux operating systems.

These updated packages fix the following bugs:

* when run on SMP systems, 64-bit Windows 2003 Server and 64-bit Windows
2008 Server only use the boot CPU for time-keeping, despite configuring the
RTC interrupt for broadcast. KVM cannot tell, therefore, if the RTC
interrupt can be used for time-keeping purposes or not. Consequently,
64-bit Windows 2003 Server and 64-bit Windows 2008 Server showed
significant clock drift when run as guests on SMP systems. With this
update, KVM now checks the RTC interrupt only on vcpu0, the 64-bit Windows
2003 Server and 64-bit Windows 2008 Server boot CPU when they run as SMP
guests under KVM. (BZ#577266)

* some Linux-based para-virtualised guests (eg Fedora 11 and Fedora 12)
which accessed para-virtualised (PV) MMU page tables crashed during startup
when launched on AMD-based hosts which had Rapid Virtualization Indexing
(RVI, formerly known as Nested Page Tables or NPT) disabled. (RVI is AMD's
hardware-assisted virtualization technology for allowing guests to modify
their own MMU page tables. It was called NPT during development.)

The crash occurred because a system call made by such guests (via the
hypercall driver) attempted to write to a read-only page. With this update,
the PV MMU reporting capability was disabled and Linux-based guests which
make these calls no longer cause KVM to inject a page fault and crash.
(BZ#578579)

* an error in irq_source_id size verification meant guest operating systems
with eight assigned virtual functions (VF) hung on boot. This update
corrects the error: verification is now done using bit numbers, not bytes
and guests with eight VFs bound to the pci-stub driver boot (and can use
the assigned virtual devices) as expected. (BZ#579863)

* in some circumstances, memory was reported as still SwapCached and Cached
even after all virtual machines were quit and all the processes whose
memory had been swapped out were no longer running. Although this memory is
eventually reclaimed by the system, available free memory is a factor in
deciding which host to use when launching a virtual machine: inaccurately
reported memory could result in sub-optimal host allocation. With this
update, kvm explicitly removes old pages from swapcache if they are the
last mapped page, ensuring reported free memory is accurate. (BZ#581764)

* as part of the qcow2 image format, each cluster has an associate
reference count (refcount) that takes two values: zero (free) and not-zero
(in use). These refcounts are stored in a refcount block which, itself, has
a refcount. Previously, the refcount of this refcount block was only
updated after cluster refcount allocation had finished. If an I/O error
occurred during refcount allocation, however, the not updated refcount
block refcount could cause the qcow2 image to corrupt. With this update,
the refcount block's refcount is automatically changed as cluster refcount
allocation occurs, ensuring it is always accurate and protecting the qcow2
image in the event of I/O errors. (BZ#581766)

* an abort() call was incorrectly added to an I/O error condition. As a
consequence, in some circumstances, if a guest was writing a file and an
I/O error occurred, the entire guest would crash. This update removes the
call and corrects this regression. If the equivalent I/O error now occurs,
the guest stops trying to write the file (and a "free_clusters failed"
error is logged) but otherwise continues unaffected. (BZ#586246)

All KVM users should upgrade to these updated packages, which contain
backported patches to resolve these issues.


Solution

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

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/docs/DOC-11259

Updated packages

RHEL Desktop Multi OS (v. 5 client)

SRPMS:
kvm-83-164.el5_5.9.src.rpm
File outdated by:  RHSA-2014:0163
    MD5: 86ddbd6d4de54ec78d3a04c5015f0d8c
SHA-256: 675b513cf56e6f72b6f29d20cbf69fb4ed2b835ae2e06651931f747988ad8a54
 
x86_64:
kmod-kvm-83-164.el5_5.9.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: 5443bb7e63cb7ff1a11aaea47b3917db
SHA-256: 5769429645edf60d7ee8f38a203b21dc49011e1410d6dfa871be0218c6c23e6e
kvm-83-164.el5_5.9.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: 678b25fa9b17aa8496e20231b5134cb9
SHA-256: 753e1aef4781a1f28346ed590f49fb94ce31e8654d8d55c7a5dff74bf7e4cd67
kvm-qemu-img-83-164.el5_5.9.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: d2acb1ba0becd5a1bbe05d05c88c1395
SHA-256: 14ddfbfd0bc7bb66bd30d4521d7d0efade13b7983e573e992e122121459e93e7
kvm-tools-83-164.el5_5.9.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: a75c7ccbfc5b171119ed4dc858724f30
SHA-256: 1d8fa796a56ed830459796e4e6d325c321cf89f806c6204a1d7d370283733b9f
 
RHEL Virtualization (v. 5 server)

SRPMS:
kvm-83-164.el5_5.9.src.rpm
File outdated by:  RHSA-2014:0163
    MD5: 86ddbd6d4de54ec78d3a04c5015f0d8c
SHA-256: 675b513cf56e6f72b6f29d20cbf69fb4ed2b835ae2e06651931f747988ad8a54
 
x86_64:
kmod-kvm-83-164.el5_5.9.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: 5443bb7e63cb7ff1a11aaea47b3917db
SHA-256: 5769429645edf60d7ee8f38a203b21dc49011e1410d6dfa871be0218c6c23e6e
kvm-83-164.el5_5.9.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: 678b25fa9b17aa8496e20231b5134cb9
SHA-256: 753e1aef4781a1f28346ed590f49fb94ce31e8654d8d55c7a5dff74bf7e4cd67
kvm-qemu-img-83-164.el5_5.9.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: d2acb1ba0becd5a1bbe05d05c88c1395
SHA-256: 14ddfbfd0bc7bb66bd30d4521d7d0efade13b7983e573e992e122121459e93e7
kvm-tools-83-164.el5_5.9.x86_64.rpm
File outdated by:  RHSA-2014:0163
    MD5: a75c7ccbfc5b171119ed4dc858724f30
SHA-256: 1d8fa796a56ed830459796e4e6d325c321cf89f806c6204a1d7d370283733b9f
 
(The unlinked packages above are only available from the Red Hat Network)

Bugs fixed (see bugzilla for more information)

577266 - Time drift in win2k3-64bit and win2k8-64bit smp guest
578579 - Linux pvmmu guests (FC11, FC12, etc) crash on boot on AMD hosts with NPT disabled
579863 - SR-IOV -- Guest exit and host hang on if boot VM with 8 VFs assigned
581764 - memory reported as used (by SwapCache and by Cache) though no process holds it.
581766 - qcow2 corruption with I/O error during refcount block allocation
586246 - Guest aborted when make guest stop on write error



These packages are GPG signed by Red Hat for security. Our key and details on how to verify the signature are available from:
https://www.redhat.com/security/team/key/#package

The Red Hat security contact is secalert@redhat.com. More contact details at http://www.redhat.com/security/team/contact/