From nobody Wed Jul 1 17:38:19 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9071DC433EF for ; Fri, 17 Dec 2021 17:57:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239996AbhLQR5d (ORCPT ); Fri, 17 Dec 2021 12:57:33 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:51430 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S239954AbhLQR5a (ORCPT ); Fri, 17 Dec 2021 12:57:30 -0500 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 1BHGjoWf007763; Fri, 17 Dec 2021 17:57:30 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=tK18PJ+o6Cs6jJp7h8xtyvRMp561ZDn02/l2HKG+kkk=; b=Cw1ycCSvL3R43m5fpDzC6t4LP4McWMqeZCHhqkQAGNeyCzv2qA1e+XSMLc4oOX4pmDYb exCopgoUPtZ9nZoSZG+kSXKekWFsUaTDBQQEeSaQ38fJuBt/7H4cfkE9O8gmrdw8bQL7 RlTPEiCKutI61z7YsuU97EN9FP0YI2ctwzliKNNupDBQxrVL5PmTj67vEgHx1siVhkE8 msRYSx3zeHaGh36SLLPl2AkLIkGie+kPul1VO6YqoX6uCxa5B+zPVwjyqwCXtio54ENa kfqc6a+rTxslUwml6OqcJvFLYU3tMT86HKPRlsn3cVZmqObp/dzUXSyxpFb346dDAAS0 nQ== Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com with ESMTP id 3d0pedmqma-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 17 Dec 2021 17:57:29 +0000 Received: from m0098420.ppops.net (m0098420.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 1BHHRbXa025423; Fri, 17 Dec 2021 17:57:29 GMT Received: from ppma06fra.de.ibm.com (48.49.7a9f.ip4.static.sl-reverse.com [159.122.73.72]) by mx0b-001b2d01.pphosted.com with ESMTP id 3d0pedmqkp-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 17 Dec 2021 17:57:29 +0000 Received: from pps.filterd (ppma06fra.de.ibm.com [127.0.0.1]) by ppma06fra.de.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 1BHH5cif009241; Fri, 17 Dec 2021 17:57:27 GMT Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by ppma06fra.de.ibm.com with ESMTP id 3cy77ptsfv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 17 Dec 2021 17:57:27 +0000 Received: from d06av24.portsmouth.uk.ibm.com (mk.ibm.com [9.149.105.60]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 1BHHvNOq38404592 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 17 Dec 2021 17:57:24 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D0A394204F; Fri, 17 Dec 2021 17:57:23 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 319E242041; Fri, 17 Dec 2021 17:57:23 +0000 (GMT) Received: from li-c6ac47cc-293c-11b2-a85c-d421c8e4747b.ibm.com.com (unknown [9.171.25.249]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Fri, 17 Dec 2021 17:57:23 +0000 (GMT) From: Pierre Morel 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 Subject: [PATCH v6 1/1] s390x: KVM: guest support for topology function Date: Fri, 17 Dec 2021 18:58:27 +0100 Message-Id: <20211217175827.134108-2-pmorel@linux.ibm.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20211217175827.134108-1-pmorel@linux.ibm.com> References: <20211217175827.134108-1-pmorel@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: XKj6Tf6fYRUu8ZjzBcWc0gznS1g_zNH2 X-Proofpoint-GUID: eL5anPCtT9-WANvUUFhuEodi_YyCq7NS X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.790,Hydra:6.0.425,FMLib:17.11.62.513 definitions=2021-12-17_07,2021-12-16_01,2021-12-02_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 mlxlogscore=999 priorityscore=1501 lowpriorityscore=0 impostorscore=0 mlxscore=0 malwarescore=0 clxscore=1015 bulkscore=0 suspectscore=0 spamscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2110150000 definitions=main-2112170100 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" We let the userland hypervisor know if the machine support the CPU topology facility using a new KVM capability: KVM_CAP_S390_CPU_TOPOLOGY. The PTF instruction will report a topology change if there is any change with a previous STSI_15_1_2 SYSIB. Changes inside a STSI_15_1_2 SYSIB occur if CPU bits are set or clear inside the CPU Topology List Entry CPU mask field, which happens with changes in CPU polarization, dedication, CPU types and adding or removing CPUs in a socket. The reporting to the guest is done using the Multiprocessor Topology-Change-Report (MTCR) bit of the utility entry of the guest's SCA which will be cleared during the interpretation of PTF. To check if the topology has been modified we use a new field of the arch vCPU to save the previous real CPU ID at the end of a schedule and verify on next schedule that the CPU used is in the same socket. We do not report polarization, CPU Type or dedication change. STSI(15.1.x) gives information on the CPU configuration topology. Let's accept the interception of STSI with the function code 15 and let the userland part of the hypervisor handle it when userland support the CPU Topology facility. Signed-off-by: Pierre Morel Reviewed-by: Claudio Imbrenda --- Documentation/virt/kvm/api.rst | 16 +++++++++++ arch/s390/include/asm/kvm_host.h | 12 ++++++-- arch/s390/kvm/kvm-s390.c | 48 +++++++++++++++++++++++++++++++- arch/s390/kvm/kvm-s390.h | 25 +++++++++++++++++ arch/s390/kvm/priv.c | 14 +++++++--- arch/s390/kvm/vsie.c | 3 ++ include/uapi/linux/kvm.h | 1 + 7 files changed, 111 insertions(+), 8 deletions(-) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index aeeb071c7688..81038429d6db 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -7484,3 +7484,19 @@ The argument to KVM_ENABLE_CAP is also a bitmask, an= d 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 faci= lity +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_h= ost.h index a604d51acfc8..df039b9f0a39 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]; }; =20 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]; }; =20 @@ -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; }; =20 struct kvm_vm_stat { diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 14a18ba5ff2c..b7424a6b9263 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 =3D is_prot_virt_host(); break; + case KVM_CAP_S390_CPU_TOPOLOGY: + r =3D test_facility(11); + break; default: r =3D 0; } @@ -817,6 +820,20 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kv= m_enable_cap *cap) icpt_operexc_on_all_vcpus(kvm); r =3D 0; break; + case KVM_CAP_S390_CPU_TOPOLOGY: + r =3D -EINVAL; + mutex_lock(&kvm->lock); + if (kvm->created_vcpus) { + r =3D -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 =3D 0; + } + mutex_unlock(&kvm->lock); + VM_EVENT(kvm, 3, "ENABLE: CPU TOPOLOGY %s", + r ? "(not available)" : "(success)"); + break; default: r =3D -EINVAL; break; @@ -3089,18 +3106,40 @@ __u64 kvm_s390_get_cpu_timer(struct kvm_vcpu *vcpu) return value; } =20 -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 =3D vcpu->kvm->arch.sca; + + ipte_lock(vcpu); + WRITE_ONCE(esca->utility, ESCA_UTILITY_MTCR); + ipte_unlock(vcpu); +} =20 +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 =3D cpu; + + if (kvm_s390_topology_changed(vcpu)) + kvm_s390_vcpu_set_mtcr(vcpu); } =20 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) { + /* Remember which CPU was backing the vCPU */ + vcpu->arch.prev_cpu =3D vcpu->cpu; vcpu->cpu =3D -1; if (vcpu->arch.cputm_enabled && !is_vcpu_idle(vcpu)) __stop_cpu_timer_accounting(vcpu); @@ -3220,6 +3259,13 @@ static int kvm_s390_vcpu_setup(struct kvm_vcpu *vcpu) vcpu->arch.sie_block->ecb |=3D ECB_HOSTPROTINT; if (test_kvm_facility(vcpu->kvm, 9)) vcpu->arch.sie_block->ecb |=3D ECB_SRSI; + + /* PTF needs guest facilities to enable interpretation */ + if (test_kvm_facility(vcpu->kvm, 11)) + vcpu->arch.sie_block->ecb |=3D ECB_PTF; + /* Indicate this is a new vcpu */ + vcpu->arch.prev_cpu =3D S390_KVM_TOPOLOGY_NEW_CPU; + if (test_kvm_facility(vcpu->kvm, 73)) vcpu->arch.sie_block->ecb |=3D 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 c07a050d757d..f664d120a5aa 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -488,4 +488,29 @@ void kvm_s390_vcpu_crypto_reset_all(struct kvm *kvm); */ extern unsigned int diag9c_forwarding_hz; =20 +#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 =3D=3D 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) !=3D + 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); =20 - if (fc > 3) { - kvm_s390_set_psw_cc(vcpu, 3); - return 0; - } + if (fc > 3 && fc !=3D 15) + goto out_no_data; + + /* fc 15 is provided with PTF/CPU topology support */ + if (fc =3D=3D 15 && !test_kvm_facility(vcpu->kvm, 11)) + goto out_no_data; =20 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 vsi= e_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 |=3D scb_o->ecb & ECB_HOSTPROTINT; + /* CPU Topology */ + if (test_kvm_facility(vcpu->kvm, 11)) + scb_s->ecb |=3D 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 1daa45268de2..273c62dfbe9a 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1131,6 +1131,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_EXIT_ON_EMULATION_FAILURE 204 #define KVM_CAP_ARM_MTE 205 #define KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM 206 +#define KVM_CAP_S390_CPU_TOPOLOGY 207 =20 #ifdef KVM_CAP_IRQ_ROUTING =20 --=20 2.27.0