Messages in this thread Patch in this message | | | Subject | Re: [PATCH v10 25/26] KVM: s390: CPU model support for AP virtualization | From | Tony Krowiak <> | Date | Fri, 21 Sep 2018 19:31:07 -0400 |
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On 09/12/2018 03:43 PM, Tony Krowiak wrote: > From: Tony Krowiak <akrowiak@linux.ibm.com> > > Introduces a new CPU model feature and two CPU model > facilities to support AP virtualization for KVM guests. > > CPU model feature: > > The KVM_S390_VM_CPU_FEAT_AP feature indicates that > AP instructions are available on the guest. This > feature will be enabled by the kernel only if the AP > instructions are installed on the linux host. This feature > must be specifically turned on for the KVM guest from > userspace to use the VFIO AP device driver for guest > access to AP devices. > > CPU model facilities: > > 1. AP Query Configuration Information (QCI) facility is installed. > > This is indicated by setting facilities bit 12 for > the guest. The kernel will not enable this facility > for the guest if it is not set on the host. > > If this facility is not set for the KVM guest, then only > APQNs with an APQI less than 16 will be used by a Linux > guest regardless of the matrix configuration for the virtual > machine. This is a limitation of the Linux AP bus. > > 2. AP Facilities Test facility (APFT) is installed. > > This is indicated by setting facilities bit 15 for > the guest. The kernel will not enable this facility for > the guest if it is not set on the host. > > If this facility is not set for the KVM guest, then no > AP devices will be available to the guest regardless of > the guest's matrix configuration for the virtual > machine. This is a limitation of the Linux AP bus. > > Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com> > Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> > Reviewed-by: Halil Pasic <pasic@linux.ibm.com> > Reviewed-by: David Hildenbrand <david@redhat.com> > Tested-by: Michael Mueller <mimu@linux.ibm.com> > Tested-by: Farhan Ali <alifm@linux.ibm.com> > Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> > --- > arch/s390/kvm/kvm-s390.c | 5 +++++ > arch/s390/tools/gen_facilities.c | 2 ++ > 2 files changed, 7 insertions(+), 0 deletions(-) > > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index 286c2e0..f0b8e2a 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -371,6 +371,11 @@ static void kvm_s390_cpu_feat_init(void) > > if (MACHINE_HAS_ESOP) > allow_cpu_feat(KVM_S390_VM_CPU_FEAT_ESOP); > + > + /* Check if AP instructions installed on host */ > + if (ap_instructions_available()) > + allow_cpu_feat(KVM_S390_VM_CPU_FEAT_AP); > + > /* > * We need SIE support, ESOP (PROT_READ protection for gmap_shadow), > * 64bit SCAO (SCA passthrough) and IDTE (for gmap_shadow unshadowing). > diff --git a/arch/s390/tools/gen_facilities.c b/arch/s390/tools/gen_facilities.c > index 0c85aed..fd788e0 100644 > --- a/arch/s390/tools/gen_facilities.c > +++ b/arch/s390/tools/gen_facilities.c > @@ -106,6 +106,8 @@ struct facility_def { > > .name = "FACILITIES_KVM_CPUMODEL", > .bits = (int[]){ > + 12, /* AP Query Configuration Information */ > + 15, /* AP Facilities Test */ > 156, /* etoken facility */ > -1 /* END */ > } >
The fixup! patch below modifies this patch (25/26) to illustrate how David's recommendation will be implemented for v11 of the series. It is one of three fixup! patches (the other two are in responses to 03/26 and 11/26) included to generate discussion in v10 rather than waiting until v11 for comments.
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From: Tony Krowiak <akrowiak@linux.ibm.com> Date: Thu, 20 Sep 2018 13:28:07 -0400 Subject: [FIXUP v10] fixup!: KVM: s390: CPU model support for AP virtualization
--- arch/s390/kvm/kvm-s390.c | 4 ---- 1 files changed, 0 insertions(+), 4 deletions(-)
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index a3a7cd9..ff38251 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -372,10 +372,6 @@ static void kvm_s390_cpu_feat_init(void) if (MACHINE_HAS_ESOP) allow_cpu_feat(KVM_S390_VM_CPU_FEAT_ESOP);
- /* Check if AP instructions installed on host */ - if (ap_instructions_available()) - allow_cpu_feat(KVM_S390_VM_CPU_FEAT_AP); - /* * We need SIE support, ESOP (PROT_READ protection for gmap_shadow), * 64bit SCAO (SCA passthrough) and IDTE (for gmap_shadow unshadowing). -- 1.7.1
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