198c1eb6b4
qemuDomainAlignMemorySizes() has an operation order problem. We are
calculating 'initialmem' without aligning the memory modules first.
Since we're aligning the dimms afterwards this can create inconsistencies
in the end result. x86 has alignment of 1-2MiB and it's not severely
impacted by it, but pSeries works with 256MiB alignment and the difference
is noticeable.
This is the case of the existing 'memory-hotplug-ppc64-nonuma' test.
The test consists of a 2GiB (aligned value) guest with 2 ~520MiB dimms,
both unaligned. 'initialmem' is calculated by taking total_mem and
subtracting the dimms size (via virDomainDefGetMemoryInitial()), which
wil give us 2GiB - 520MiB - 520MiB, ending up with a little more than
an 1GiB of 'initialmem'. Note that this value is now unaligned, and
will be aligned up via VIR_ROUND_UP(), and we'll end up with 'initialmem'
of 1GiB + 256MiB. Given that the dimms are aligned later on, the end
result for QEMU is that the guest will have a 'mem' size of 1310720k,
plus the two 512 MiB dimms, exceeding in 256MiB the desired 2GiB
memory and currentMemory specified in the XML.
Existing guests can't be fixed without breaking ABI, but we have
code already in place to align pSeries NVDIMM modules for new guests.
Let's extend it to align all pSeries mem modules.
A new test, 'memory-hotplug-ppc64-nonuma-abi-update', a copy of the
existing 'memory-hotplug-ppc64-nonuma', was added to demonstrate the
result for new pSeries guests. For the same unaligned XML mentioned
above, after applying this patch:
- starting QEMU mem size without PARSE_ABI_UPDATE:
-m size=1310720k,slots=16,maxmem=4194304k \ (no changes)
- starting QEMU mem size with PARSE_ABI_UPDATE:
-m size=1048576k,slots=16,maxmem=4194304k \ (size fixed)
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Libvirt API for virtualization
Libvirt provides a portable, long term stable C API for managing the virtualization technologies provided by many operating systems. It includes support for QEMU, KVM, Xen, LXC, bhyve, Virtuozzo, VMware vCenter and ESX, VMware Desktop, Hyper-V, VirtualBox and the POWER Hypervisor.
For some of these hypervisors, it provides a stateful management daemon which runs on the virtualization host allowing access to the API both by non-privileged local users and remote users.
Layered packages provide bindings of the libvirt C API into other languages including Python, Perl, PHP, Go, Java, OCaml, as well as mappings into object systems such as GObject, CIM and SNMP.
Further information about the libvirt project can be found on the website:
License
The libvirt C API is distributed under the terms of GNU Lesser General Public License, version 2.1 (or later). Some parts of the code that are not part of the C library may have the more restrictive GNU General Public License, version 2.0 (or later). See the files COPYING.LESSER and COPYING for full license terms & conditions.
Installation
Instructions on building and installing libvirt can be found on the website:
https://libvirt.org/compiling.html
Contributing
The libvirt project welcomes contributions in many ways. For most components the best way to contribute is to send patches to the primary development mailing list. Further guidance on this can be found on the website:
https://libvirt.org/contribute.html
Contact
The libvirt project has two primary mailing lists:
- libvirt-users@redhat.com (for user discussions)
- libvir-list@redhat.com (for development only)
Further details on contacting the project are available on the website: