From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Krowiak Subject: Re: [PATCH v2 08/15] KVM: s390: interface to enable AP execution mode Date: Wed, 28 Feb 2018 15:37:49 -0500 Message-ID: <47808b6f-9e6d-1f17-c26b-3e03d1f1e2ca@linux.vnet.ibm.com> References: <1519741693-17440-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1519741693-17440-9-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: David Hildenbrand , 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, 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, jjherne@linux.vnet.ibm.com, thuth@redhat.com, pasic@linux.vnet.ibm.com, fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com List-ID: On 02/28/2018 04:42 AM, David Hildenbrand wrote: > On 27.02.2018 15:28, Tony Krowiak wrote: >> Introduces a new interface to enable AP interpretive >> execution (IE) mode for the KVM guest. When running >> with IE mode enabled, AP instructions executed on the >> KVM guest will be interpreted by the firmware and >> passed directly through to an AP device installed on >> the system. The CPU model feature for AP must >> be enabled for the KVM guest in order to enable >> interpretive execution mode. >> >> This interface will be used in a subsequent patch >> by the VFIO AP device driver. >> >> Signed-off-by: Tony Krowiak >> --- >> arch/s390/include/asm/kvm-ap.h | 2 ++ >> arch/s390/include/asm/kvm_host.h | 1 + >> arch/s390/kvm/kvm-ap.c | 27 +++++++++++++++++++++++++++ >> arch/s390/kvm/kvm-s390.h | 1 + >> 4 files changed, 31 insertions(+), 0 deletions(-) >> >> diff --git a/arch/s390/include/asm/kvm-ap.h b/arch/s390/include/asm/kvm-ap.h >> index 46e7c5b..6bd6bfb 100644 >> --- a/arch/s390/include/asm/kvm-ap.h >> +++ b/arch/s390/include/asm/kvm-ap.h >> @@ -51,4 +51,6 @@ struct kvm_ap_matrix { >> >> void kvm_ap_deconfigure_matrix(struct kvm *kvm); >> >> +int kvm_ap_enable_ie_mode(struct kvm *kvm); >> + >> #endif /* _ASM_KVM_AP */ >> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h >> index a4c77d3..1eebdd6 100644 >> --- a/arch/s390/include/asm/kvm_host.h >> +++ b/arch/s390/include/asm/kvm_host.h >> @@ -186,6 +186,7 @@ struct kvm_s390_sie_block { >> #define ECA_AIV 0x00200000 >> #define ECA_VX 0x00020000 >> #define ECA_PROTEXCI 0x00002000 >> +#define ECA_APIE 0x00000008 >> #define ECA_SII 0x00000001 >> __u32 eca; /* 0x004c */ >> #define ICPT_INST 0x04 >> diff --git a/arch/s390/kvm/kvm-ap.c b/arch/s390/kvm/kvm-ap.c >> index bb29045..862e54b 100644 >> --- a/arch/s390/kvm/kvm-ap.c >> +++ b/arch/s390/kvm/kvm-ap.c >> @@ -307,3 +307,30 @@ void kvm_ap_deconfigure_matrix(struct kvm *kvm) >> kvm_ap_clear_crycb_masks(kvm); >> } >> EXPORT_SYMBOL(kvm_ap_deconfigure_matrix); >> + >> +/** >> + * kvm_ap_enable_ie_mode >> + * >> + * Enable interpretrive execution of AP instructions for the guest. When >> + * enabled, AP instructions executed on the guest will be interpreted and >> + * passed through to an AP installed on the host system. >> + * >> + * Returns 0 if interpretrive execution is enabled. Returns -EOPNOTSUPP >> + * if AP facilities are not installed for the guest. >> + * >> + * @kvm: the guest's kvm structure >> + */ >> +int kvm_ap_enable_ie_mode(struct kvm *kvm) >> +{ >> + int i; >> + struct kvm_vcpu *vcpu; >> + >> + if (!test_kvm_cpu_feat(kvm, KVM_S390_VM_CPU_FEAT_AP)) >> + return -EOPNOTSUPP; >> + >> + kvm_for_each_vcpu(i, vcpu, kvm) >> + vcpu->arch.sie_block->eca |= ECA_APIE; >> + >> + return 0; >> +} >> +EXPORT_SYMBOL(kvm_ap_enable_ie_mode); >> diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h >> index 1b5621f..3142541 100644 >> --- a/arch/s390/kvm/kvm-s390.h >> +++ b/arch/s390/kvm/kvm-s390.h >> @@ -18,6 +18,7 @@ >> #include >> #include >> #include >> +#include >> >> /* Transactional Memory Execution related macros */ >> #define IS_TE_ENABLED(vcpu) ((vcpu->arch.sie_block->ecb & ECB_TE)) >> > What about VSIE? That is a good question. I'm beginning to think introducing AP on second level guests ought to be postponed for now. I'm going to look into this further. >