Hi,
Has anyone here managed to get cpu masking working via libvirt? Intention to enable VM migrations between hosts of a different CPU generation.
Inside my xml I'm providing the model as well as a list of features to specifically disable, but none of it seems to take any effect. On booting the VM I still see the disabled flags in /proc/cpuinfo
<cpu match='exact' mode='custom'> <arch>x86_64</arch> <model fallback='forbid'>Westmere</model> <feature policy='disable' name='dtherm'/> <feature policy='disable' name='erms'/> <feature policy='disable' name='fsgsbase'/> <feature policy='disable' name='pts'/> <feature policy='disable' name='pln'/> <feature policy='disable' name='rdrand'/> <feature policy='disable' name='f16c'/> <feature policy='disable' name='aes'/> <feature policy='disable' name='tsc_deadline_timer'/> <feature policy='disable' name='x2apic'/> <feature policy='disable' name='dtherm'/> <feature policy='disable' name='pclmulqdq'/> </cpu>
Doing a dumpxml against the domU once it's booted leaves out the entire <cpu> section, leading me to think maybe libvirt is dropping it for some reason. I've got the above <cpu> just in the main <domain> section.
Anyone have this working or able to offer some suggestions?
Thanks!
- Nathan
On 8/26/2014 4:52 PM, Nathan March wrote:
Has anyone here managed to get cpu masking working via libvirt? Intention to enable VM migrations between hosts of a different CPU generation.
To add to this, I've tried using the boot options to set the cpu mask instead:
xen_commandline : dom0_mem=2048M,max:2048M loglvl=all guest_loglvl=all cpuid_mask_ecx=0x009ee3fd cpuid_mask_edx=0xbfebfbff
Unfortunately still no luck. There's no errors in xm dmesg to indicate the settings were / weren't applied, it simply doesn't seem to do anything.
- Nathan
Hi,
I guess this is the wrong approach:
Libvirt does manage cpu type in an xml file, you would have to alter this xml file:
/usr/share/libvirt/cpu_map.xml
HTH
PS: Maybe add an feature request upstream to enable this for all libvirt users?
I have seen this request quite some time on different mailing lists.
Am 27.08.2014 20:08, schrieb Nathan March:
On 8/26/2014 4:52 PM, Nathan March wrote:
Has anyone here managed to get cpu masking working via libvirt? Intention to enable VM migrations between hosts of a different CPU generation.
To add to this, I've tried using the boot options to set the cpu mask instead:
xen_commandline : dom0_mem=2048M,max:2048M loglvl=all guest_loglvl=all cpuid_mask_ecx=0x009ee3fd cpuid_mask_edx=0xbfebfbff
Unfortunately still no luck. There's no errors in xm dmesg to indicate the settings were / weren't applied, it simply doesn't seem to do anything.
- Nathan
CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
-
Nathan March -
Sven Kieske