[PATCH 0/2] KVM enablement for facility bit 81 and 82

Khaled Elmously khalid.elmously at canonical.com
Fri Feb 9 05:07:26 UTC 2018


On 2018-02-08 15:43:27 , Joseph Salisbury wrote:
> On 02/08/2018 01:55 PM, Khaled Elmously wrote:
> > On 2018-02-02 17:58:22 , Joseph Salisbury wrote:
> >> On 02/02/2018 05:54 PM, Joseph Salisbury wrote:
> >>> From: Christian Borntraeger <borntraeger at de.ibm.com>
> >>>
> >>> BugLink: http://bugs.launchpad.net/bugs/1747090
> >>>
> >>> == SRU Justification ==
> >>> Mainline commit 35b3fde6203b9 is a KVM patch for s390x to provide
> >>> facility bits 81 (ppa15) and 82 (bpb).  This is required for branch prediction
> >>> behaviour changes.
> >>>
> >>> This is the public bug for SRU.  There is also a priave bug report:
> >>> http://bugs.launchpad.net/bugs/1743560
> >>>
> >>> There is a qemu portion to this fix:
> >>> http://patchwork.ozlabs.org/cover/862801/
> >>>
> >>> This fix is also requred in Artful and Bionic, but Xenial requires a prereq commit,
> >>> so it is being SRU'd separatly.
> >>>
> >>> == Fixes ==
> >>> ed8dda0bf74b ("Enable all facility bits that are known good for passthrough")
> >>> 35b3fde6203b ("KVM: s390: wire up bpb feature")
> >>>
> >>>
> >>> == Regression Potential ==
> >>> Low, this fix is limited to s390.
> >>>
> >>> == Test Case ==
> >>> A test kernel was built with these patches and tested by the original bug
> >>> reporter.  The bug reporter states the test kernel resolved the bug.
> >>>
> >>>
> >>>
> >>> Alexander Yarygin (1):
> >>>   KVM: s390: Enable all facility bits that are known good for
> >>>     passthrough
> >>>
> >>> Christian Borntraeger (1):
> >>>   KVM: s390: wire up bpb feature
> >>>
> >>>  arch/s390/include/asm/kvm_host.h |  3 ++-
> >>>  arch/s390/include/uapi/asm/kvm.h |  3 +++
> >>>  arch/s390/kvm/kvm-s390.c         | 16 ++++++++++++++--
> >>>  include/uapi/linux/kvm.h         |  1 +
> >>>  4 files changed, 20 insertions(+), 3 deletions(-)
> >>>
> >> This request is for Xenial.  I missed adding that to the subject. 
> >> Artful and Bionic are in a seperate SRU request.
> >>
> > I'm curious how you realized that you need a pre-requisite commit (given that the desired commit would have applied more-or-less cleanly anyway as it did for artful)? Was that by testing?
> >
> > The patchset doesn't look wrong to me at all, I'm just asking for my general knowledge.
> The prereq commit was identified by IBM internally.  They posted the
> first version of the backports in the private bug[0], in comment #4.
> 
> [0] http://pad.lv/1743560

The bug isn't accessible to me - but that's fine, I was just wondering how you knew about the pre-requisite.
Thanks for the answer!
-Khaled

> 
> >
> >
> >> -- 
> >> kernel-team mailing list
> >> kernel-team at lists.ubuntu.com
> >> https://lists.ubuntu.com/mailman/listinfo/kernel-team
> 
> 
> 




More information about the kernel-team mailing list