[v7,1/1] s390x: KVM: guest support for topology function

Message ID	20220217095923.114489-2-pmorel@linux.ibm.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <kvm-owner@kernel.org> From: Pierre Morel <pmorel@linux.ibm.com> To: kvm@vger.kernel.org Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, borntraeger@de.ibm.com, frankja@linux.ibm.com, cohuck@redhat.com, david@redhat.com, thuth@redhat.com, imbrenda@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, pmorel@linux.ibm.com, wintera@linux.ibm.com, seiden@linux.ibm.com, nrb@linux.ibm.com Subject: [PATCH v7 1/1] s390x: KVM: guest support for topology function Date: Thu, 17 Feb 2022 10:59:23 +0100 Message-Id: <20220217095923.114489-2-pmorel@linux.ibm.com> In-Reply-To: <20220217095923.114489-1-pmorel@linux.ibm.com> References: <20220217095923.114489-1-pmorel@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	s390x: KVM: CPU Topology \| expand [v7,0/1] s390x: KVM: CPU Topology [v7,1/1] s390x: KVM: guest support for topology function

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index a4267104db50..8b8e8b5758e0 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -7561,3 +7561,19 @@ The argument to KVM_ENABLE_CAP is also a bitmask, and must be a subset of the result of KVM_CHECK_EXTENSION. KVM will forward to userspace the hypercalls whose corresponding bit is in the argument, and return ENOSYS for the others. + +8.17 KVM_CAP_S390_CPU_TOPOLOGY +------------------------------ + +:Capability: KVM_CAP_S390_CPU_TOPOLOGY +:Architectures: s390 +:Type: vm + +This capability indicates that kvm will provide the S390 CPU Topology facility +which consist of the interpretation of the PTF instruction for the Function +Code 2 along with interception and forwarding of both the PTF instruction +with Function Codes 0 or 1 and the STSI(15,1,x) instruction to the userland +hypervisor. + +The stfle facility 11, CPU Topology facility, should not be provided to the +guest without this capability. diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index a22c9266ea05..c7d5720d6aec 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -95,15 +95,19 @@ struct bsca_block { union ipte_control ipte_control; __u64 reserved[5]; __u64 mcn; - __u64 reserved2; +#define ESCA_UTILITY_MTCR 0x8000 + __u16 utility; + __u8 reserved2[6]; struct bsca_entry cpu[KVM_S390_BSCA_CPU_SLOTS]; }; struct esca_block { union ipte_control ipte_control; - __u64 reserved1[7]; + __u64 reserved1[6]; + __u16 utility; + __u8 reserved2[6]; __u64 mcn[4]; - __u64 reserved2[20]; + __u64 reserved3[20]; struct esca_entry cpu[KVM_S390_ESCA_CPU_SLOTS]; }; @@ -247,6 +251,7 @@ struct kvm_s390_sie_block { #define ECB_SPECI 0x08 #define ECB_SRSI 0x04 #define ECB_HOSTPROTINT 0x02 +#define ECB_PTF 0x01 __u8 ecb; /* 0x0061 */ #define ECB2_CMMA 0x80 #define ECB2_IEP 0x20 @@ -748,6 +753,7 @@ struct kvm_vcpu_arch { bool skey_enabled; struct kvm_s390_pv_vcpu pv; union diag318_info diag318_info; + int prev_cpu; }; struct kvm_vm_stat { diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 2296b1ff1e02..af7ea8488fa2 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -606,6 +606,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_S390_PROTECTED: r = is_prot_virt_host(); break; + case KVM_CAP_S390_CPU_TOPOLOGY: + r = test_facility(11); + break; default: r = 0; } @@ -817,6 +820,20 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) icpt_operexc_on_all_vcpus(kvm); r = 0; break; + case KVM_CAP_S390_CPU_TOPOLOGY: + r = -EINVAL; + mutex_lock(&kvm->lock); + if (kvm->created_vcpus) { + r = -EBUSY; + } else if (test_facility(11)) { + set_kvm_facility(kvm->arch.model.fac_mask, 11); + set_kvm_facility(kvm->arch.model.fac_list, 11); + r = 0; + } + mutex_unlock(&kvm->lock); + VM_EVENT(kvm, 3, "ENABLE: CPU TOPOLOGY %s", + r ? "(not available)" : "(success)"); + break; default: r = -EINVAL; break; @@ -3043,18 +3060,40 @@ __u64 kvm_s390_get_cpu_timer(struct kvm_vcpu *vcpu) return value; } -void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) +/** + * kvm_s390_vcpu_set_mtcr + * @vcp: the virtual CPU + * + * Is only relevant if the topology facility is present. + * + * Updates the Multiprocessor Topology-Change-Report to signal + * the guest with a topology change. + */ +static void kvm_s390_vcpu_set_mtcr(struct kvm_vcpu *vcpu) { + struct esca_block *esca = vcpu->kvm->arch.sca; + + ipte_lock(vcpu); + WRITE_ONCE(esca->utility, ESCA_UTILITY_MTCR); + ipte_unlock(vcpu); +} +void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) +{ gmap_enable(vcpu->arch.enabled_gmap); kvm_s390_set_cpuflags(vcpu, CPUSTAT_RUNNING); if (vcpu->arch.cputm_enabled && !is_vcpu_idle(vcpu)) __start_cpu_timer_accounting(vcpu); vcpu->cpu = cpu; + + if (kvm_s390_topology_changed(vcpu)) + kvm_s390_vcpu_set_mtcr(vcpu); } void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) { + /* Remember which CPU was backing the vCPU */ + vcpu->arch.prev_cpu = vcpu->cpu; vcpu->cpu = -1; if (vcpu->arch.cputm_enabled && !is_vcpu_idle(vcpu)) __stop_cpu_timer_accounting(vcpu); @@ -3174,6 +3213,13 @@ static int kvm_s390_vcpu_setup(struct kvm_vcpu *vcpu) vcpu->arch.sie_block->ecb |= ECB_HOSTPROTINT; if (test_kvm_facility(vcpu->kvm, 9)) vcpu->arch.sie_block->ecb |= ECB_SRSI; + + /* PTF needs guest facilities to enable interpretation */ + if (test_kvm_facility(vcpu->kvm, 11)) + vcpu->arch.sie_block->ecb |= ECB_PTF; + /* Indicate this is a new vcpu */ + vcpu->arch.prev_cpu = S390_KVM_TOPOLOGY_NEW_CPU; + if (test_kvm_facility(vcpu->kvm, 73)) vcpu->arch.sie_block->ecb |= ECB_TE; if (!kvm_is_ucontrol(vcpu->kvm)) diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index 098831e815e6..af04ffbfd587 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -503,4 +503,29 @@ void kvm_s390_vcpu_crypto_reset_all(struct kvm *kvm); */ extern unsigned int diag9c_forwarding_hz; +#define S390_KVM_TOPOLOGY_NEW_CPU -1 +/** + * kvm_s390_topology_changed + * @vcpu: the virtual CPU + * + * If the topology facility is present, checks if the CPU toplogy + * viewed by the guest changed due to load balancing or CPU hotplug. + */ +static inline bool kvm_s390_topology_changed(struct kvm_vcpu *vcpu) +{ + if (!test_kvm_facility(vcpu->kvm, 11)) + return false; + + /* A new vCPU has been hotplugged */ + if (vcpu->arch.prev_cpu == S390_KVM_TOPOLOGY_NEW_CPU) + return true; + + /* The real CPU backing up the vCPU moved to another socket */ + if (topology_physical_package_id(vcpu->cpu) != + topology_physical_package_id(vcpu->arch.prev_cpu)) + return true; + + return false; +} + #endif diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 417154b314a6..5ff6be498cbd 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -861,10 +861,12 @@ static int handle_stsi(struct kvm_vcpu *vcpu) if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); - if (fc > 3) { - kvm_s390_set_psw_cc(vcpu, 3); - return 0; - } + if (fc > 3 && fc != 15) + goto out_no_data; + + /* fc 15 is provided with PTF/CPU topology support */ + if (fc == 15 && !test_kvm_facility(vcpu->kvm, 11)) + goto out_no_data; if (vcpu->run->s.regs.gprs[0] & 0x0fffff00 || vcpu->run->s.regs.gprs[1] & 0xffff0000) @@ -898,6 +900,10 @@ static int handle_stsi(struct kvm_vcpu *vcpu) goto out_no_data; handle_stsi_3_2_2(vcpu, (void *) mem); break; + case 15: + trace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2); + insert_stsi_usr_data(vcpu, operand2, ar, fc, sel1, sel2); + return -EREMOTE; } if (kvm_s390_pv_cpu_is_protected(vcpu)) { memcpy((void *)sida_origin(vcpu->arch.sie_block), (void *)mem, diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index acda4b6fc851..da0397cf2cc7 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -503,6 +503,9 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) /* Host-protection-interruption introduced with ESOP */ if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_ESOP)) scb_s->ecb |= scb_o->ecb & ECB_HOSTPROTINT; + /* CPU Topology */ + if (test_kvm_facility(vcpu->kvm, 11)) + scb_s->ecb |= scb_o->ecb & ECB_PTF; /* transactional execution */ if (test_kvm_facility(vcpu->kvm, 73) && wants_tx) { /* remap the prefix is tx is toggled on */ diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 5191b57e1562..23e3913992c5 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1134,6 +1134,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_VM_GPA_BITS 207 #define KVM_CAP_XSAVE2 208 #define KVM_CAP_SYS_ATTRIBUTES 209 +#define KVM_CAP_S390_CPU_TOPOLOGY 210 #ifdef KVM_CAP_IRQ_ROUTING

[v7,1/1] s390x: KVM: guest support for topology function

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