From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Krowiak Subject: Re: [PATCH v6 05/21] KVM: s390: CPU model support for AP virtualization Date: Mon, 2 Jul 2018 11:37:11 -0400 Message-ID: <276b5ae7-7f27-faae-1e5a-0d4c084139e9@linux.ibm.com> References: <1530306683-7270-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1530306683-7270-6-git-send-email-akrowiak@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Christian Borntraeger , Tony Krowiak , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: freude@de.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@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, jjherne@linux.vnet.ibm.com, thuth@redhat.com, pasic@linux.vnet.ibm.com, berrange@redhat.com, fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com List-ID: On 07/02/2018 10:38 AM, Christian Borntraeger wrote: > > On 06/29/2018 11:11 PM, Tony Krowiak wrote: >> 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. This facility >> must not be set by userspace if the KVM_S390_VM_CPU_FEAT_AP >> feature is not installed. >> >> If this facility is not set for the KVM guest, then only >> APQNs with an APQI less than 16 will be available to the >> guest regardless of the guest's matrix configuration. This >> is a limitation of the AP bus running on the guest. >> >> 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. This facility >> must not be set by userspace if the KVM_S390_VM_CPU_FEAT_AP >> feature is not installed. >> >> 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. This is a limitation >> of the AP bus running under the guest. >> >> Reviewed-by: Christian Borntraeger >> Reviewed-by: Halil Pasic >> Signed-off-by: Tony Krowiak > I think it probably should be at the end of the series, other than that its good. If I move this to the end of the series, the very next patch checks the KVM_S390_VM_CPU_FEAT_AP feature? > > > >> --- >> arch/s390/include/uapi/asm/kvm.h | 1 + >> arch/s390/kvm/kvm-s390.c | 8 ++++++++ >> arch/s390/tools/gen_facilities.c | 3 +++ >> 3 files changed, 12 insertions(+), 0 deletions(-) >> >> diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h >> index 4cdaa55..a580dec 100644 >> --- a/arch/s390/include/uapi/asm/kvm.h >> +++ b/arch/s390/include/uapi/asm/kvm.h >> @@ -130,6 +130,7 @@ struct kvm_s390_vm_cpu_machine { >> #define KVM_S390_VM_CPU_FEAT_PFMFI 11 >> #define KVM_S390_VM_CPU_FEAT_SIGPIF 12 >> #define KVM_S390_VM_CPU_FEAT_KSS 13 >> +#define KVM_S390_VM_CPU_FEAT_AP 14 >> struct kvm_s390_vm_cpu_feat { >> __u64 feat[16]; >> }; >> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >> index 3b7a515..d2208d4 100644 >> --- a/arch/s390/kvm/kvm-s390.c >> +++ b/arch/s390/kvm/kvm-s390.c >> @@ -40,6 +40,7 @@ >> #include >> #include >> #include >> +#include >> #include "kvm-s390.h" >> #include "gaccess.h" >> >> @@ -366,6 +367,13 @@ 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() == 0) >> + 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 90a8c9e..e0e2c19 100644 >> --- a/arch/s390/tools/gen_facilities.c >> +++ b/arch/s390/tools/gen_facilities.c >> @@ -106,6 +106,9 @@ struct facility_def { >> >> .name = "FACILITIES_KVM_CPUMODEL", >> .bits = (int[]){ >> + 12, /* AP Query Configuration Information */ >> + 15, /* AP Facilities Test */ >> -1 /* END */ >> } >> },