Nina Schoetterl-Glausch <n...@linux.ibm.com> writes: > On Wed, 2023-09-20 at 13:11 +0200, Markus Armbruster wrote: >> Nina Schoetterl-Glausch <n...@linux.ibm.com> writes: >> >> > From: Pierre Morel <pmo...@linux.ibm.com> >> > >> > S390 adds two new SMP levels, drawers and books to the CPU >> > topology. >> > S390 CPUs have specific topology features like dedication and >> > entitlement. These indicate to the guest information on host >> > vCPU scheduling and help the guest make better scheduling decisions. >> > >> > Let us provide the SMP properties with books and drawers levels >> > and S390 CPU with dedication and entitlement, >> > >> > Signed-off-by: Pierre Morel <pmo...@linux.ibm.com> >> > Reviewed-by: Nina Schoetterl-Glausch <n...@linux.ibm.com> >> > Co-developed-by: Nina Schoetterl-Glausch <n...@linux.ibm.com> >> > Signed-off-by: Nina Schoetterl-Glausch <n...@linux.ibm.com> >> > diff --git a/qapi/machine-common.json b/qapi/machine-common.json >> > new file mode 100644 >> > index 0000000000..e40421bb37 >> > --- /dev/null >> > +++ b/qapi/machine-common.json >> > @@ -0,0 +1,21 @@ >> > +# -*- Mode: Python -*- >> > +# vim: filetype=python >> > +# >> > +# This work is licensed under the terms of the GNU GPL, version 2 or >> > later. >> > +# See the COPYING file in the top-level directory. >> > + >> > +## >> > +# = Machines S390 data types >> > +## >> > + >> > +## >> > +# @CpuS390Entitlement: >> > +# >> > +# An enumeration of cpu entitlements that can be assumed by a virtual >> > +# S390 CPU >> >> CPU entitlements >> >> Would someone reasonably familiar with S390 understand this? Because > > Well, someone familiar with s390 topology would, otherwise probably not tbh.
Good enough, I guess. >> I'm not and I don't; I wonder what "a virtual CPU assuming an >> entitlement" means. > > Basically, on s390x the OS is always running on some hypervisor. > Even without KVM or z/VM you can slice up the machine, namely into logical > partitions (LPARs). Therefore, there is a scheduling of virtual CPUs to the > actual physical ones. "Entitlement" is a statement about how that scheduling > works for a virtual CPU. The same concepts can then also be applied to KVM. Thanks! [...]
