[CentOS-virt] Live migration haswell, broadwell

Tue Nov 14 17:02:25 UTC 2017
Sarah Newman <srn at prgmr.com>

On 11/14/2017 03:13 AM, T.Weyergraf wrote:
> Hi
> I wonder, if live migration (back and forth) is possible on mixed Haswell (Xeon V3) and Broadwell (Xeon V4) installations. The only notable difference
> between the two is apparently a working TSX implementation on V4, which got disabled on V3 due to bugs. The rest (VMCS-shadowing, posted interrupts)
> should not apply to our environment, as we do not run nested-vmx nor device-passthrough on our Xen servers
> Now, I found no sane way to disable TSX on a given system but I cannot rule out, that some (Linux-)software, such as Postgres will use them
> eventually. Also, I have a hard time trying to assess, if TSX can be disabled on V4 to enable seamless migration.
> Any hint would be greately appreciated.

Have you looked at CPUID masking? I haven't tried this but someone wrote a handy calculator for it. https://github.com/twizted/xen_maskcalc