From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Subject: Re: kvm: RDTSCP on AMD Date: Tue, 11 Dec 2018 15:30:17 +0000 Message-ID: <20181211153017.GN921@redhat.com> References: <20181210181328.GA762@zn.tnic> <20181210183730.GJ4669@habkost.net> <20181210184153.GB5482@zn.tnic> <20181210190600.GK4669@habkost.net> <20181210194258.GD5482@zn.tnic> <20181210200843.GN4669@habkost.net> <20181211103839.GC921@redhat.com> <20181211115546.GQ4669@habkost.net> Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: Eduardo Habkost , Borislav Petkov , =?utf-8?B?SsO2cmcgUsO2ZGVs?= , Andre Przywara , kvm ML , lkml , Tom Lendacky , Eric Blake To: Paolo Bonzini Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Tue, Dec 11, 2018 at 04:23:51PM +0100, Paolo Bonzini wrote: > 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. :) Great, then, this is a non-issue - we just need to mention that fact in the commit that sets the min version for the kernel Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|