From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Schwidefsky Subject: Re: [RFC 19/19] s390/facilities: enable AP facilities needed by guest Date: Mon, 16 Oct 2017 11:25:10 +0200 Message-ID: <20171016112510.39e9c330@mschwideX1> References: <1507916344-3896-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1507916344-3896-20-git-send-email-akrowiak@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1507916344-3896-20-git-send-email-akrowiak@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Tony Krowiak Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, freude@de.ibm.com, heiko.carstens@de.ibm.com, borntraeger@de.ibm.com, cohuck@redhat.com, kwankhede@nvidia.com, bjsdjshi@linux.vnet.ibm.com, pbonzini@redhat.com, alex.williamson@redhat.com, pmorel@linux.vnet.ibm.com, alifm@linux.vnet.ibm.com, mjrosato@linux.vnet.ibm.com, qemu-s390x@nongnu.org, jjherne@linux.vnet.ibm.com, thuth@redhat.com, pasic@linux.vnet.ibm.com List-ID: On Fri, 13 Oct 2017 13:39:04 -0400 Tony Krowiak wrote: > Sets up the following facilities bits to enable the specified AP > facilities for the guest VM: > * STFLE.12: Enables the AP Query Configuration Information > facility. The AP bus running in the guest uses > the information returned from this instruction > to configure AP adapters and domains for the > guest machine. > * STFLE.15: Indicates the AP facilities test is available. > The AP bus running in the guest uses the > information. > > Signed-off-by: Tony Krowiak > --- > arch/s390/tools/gen_facilities.c | 2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) > > diff --git a/arch/s390/tools/gen_facilities.c b/arch/s390/tools/gen_facilities.c > index 70dd8f1..eeaa7db 100644 > --- a/arch/s390/tools/gen_facilities.c > +++ b/arch/s390/tools/gen_facilities.c > @@ -74,8 +74,10 @@ struct facility_def { > 8, /* enhanced-DAT 1 */ > 9, /* sense-running-status */ > 10, /* conditional sske */ > + 12, /* AP query configuration */ > 13, /* ipte-range */ > 14, /* nonquiescing key-setting */ > + 15, /* AP special-command facility */ > 73, /* transactional execution */ > 75, /* access-exception-fetch/store indication */ > 76, /* msa extension 3 */ With this all KVM guests will always have the AP instructions available, no? In principles I like this approach, but it differs from the way z/VM does things, there the guest will get an exception if it tries to execute an AP instruction if there are no AP devices assigned to the guest. I wonder if there is a reason why z/VM does it the way it does. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin.