Re: kvm: RDTSCP on AMD

From: Paolo Bonzini
Date: Tue Dec 11 2018 - 10:24:01 EST


On 11/12/18 12:55, Eduardo Habkost wrote:
>> - Debian Jessie: 4.5
>> - Debian Stretch: 4.5
>> - RHEL-7: 3.10
>> - Ubuntu LTS (Xenial): 4.5
>> - OpenSUSE Leap 15: 4.12.14
>>
>> So we can't require Linux 4.5 as a minimum version at this time.
> I'd like us to take a step back and consider what exactly
> "support" means here. QEMU will still work on older kernels if
> we add RDTSCP to the CPU models, but at the same time I would
> like to document that our strict runnability guarantees may not
> be kept if running Linux < 4.5.

Anyway RHEL does have RDTSC support for AMD, and a bunch of other stuff.
The frankenkernel's KVM is somewhere between 4.5 and 4.10, with a dash
of 4.20 of course. :)

Paolo