diff options
| -rw-r--r-- | Documentation/virtual/kvm/api.txt | 15 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/kvm_ppc.h | 2 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 71 | ||||
| -rw-r--r-- | arch/powerpc/kvm/powerpc.c | 13 |
5 files changed, 90 insertions, 12 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 4029943887a3..68b66b538d2d 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -3996,6 +3996,21 @@ Parameters: none Allow use of adapter-interruption suppression. Returns: 0 on success; -EBUSY if a VCPU has already been created. +7.11 KVM_CAP_PPC_SMT + +Architectures: ppc +Parameters: vsmt_mode, flags + +Enabling this capability on a VM provides userspace with a way to set +the desired virtual SMT mode (i.e. the number of virtual CPUs per +virtual core). The virtual SMT mode, vsmt_mode, must be a power of 2 +between 1 and 8. On POWER8, vsmt_mode must also be no greater than +the number of threads per subcore for the host. Currently flags must +be 0. A successful call to enable this capability will result in +vsmt_mode being returned when the KVM_CAP_PPC_SMT capability is +subsequently queried for the VM. This capability is only supported by +HV KVM, and can only be set before any VCPUs have been created. + 8. Other capabilities. ---------------------- diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index d3aae32acb54..e8991808ea9c 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -267,6 +267,7 @@ struct kvm_resize_hpt; struct kvm_arch { unsigned int lpid; + unsigned int smt_mode; /* # vcpus per virtual core */ #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE unsigned int tlb_sets; struct kvm_hpt_info hpt; diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h index e0d88c38602b..ba5fadd6f3c9 100644 --- a/arch/powerpc/include/asm/kvm_ppc.h +++ b/arch/powerpc/include/asm/kvm_ppc.h @@ -315,6 +315,8 @@ struct kvmppc_ops { struct irq_bypass_producer *); int (*configure_mmu)(struct kvm *kvm, struct kvm_ppc_mmuv3_cfg *cfg); int (*get_rmmu_info)(struct kvm *kvm, struct kvm_ppc_rmmu_info *info); + int (*set_smt_mode)(struct kvm *kvm, unsigned long mode, + unsigned long flags); }; extern struct kvmppc_ops *kvmppc_hv_ops; diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index aaf166e2417d..2b4484d07971 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -1628,7 +1628,7 @@ static struct kvmppc_vcore *kvmppc_vcore_create(struct kvm *kvm, int core) init_swait_queue_head(&vcore->wq); vcore->preempt_tb = TB_NIL; vcore->lpcr = kvm->arch.lpcr; - vcore->first_vcpuid = core * threads_per_vcore(); + vcore->first_vcpuid = core * kvm->arch.smt_mode; vcore->kvm = kvm; INIT_LIST_HEAD(&vcore->preempt_list); @@ -1787,14 +1787,10 @@ static struct kvm_vcpu *kvmppc_core_vcpu_create_hv(struct kvm *kvm, unsigned int id) { struct kvm_vcpu *vcpu; - int err = -EINVAL; + int err; int core; struct kvmppc_vcore *vcore; - core = id / threads_per_vcore(); - if (core >= KVM_MAX_VCORES) - goto out; - err = -ENOMEM; vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL); if (!vcpu) @@ -1842,11 +1838,17 @@ static struct kvm_vcpu *kvmppc_core_vcpu_create_hv(struct kvm *kvm, init_waitqueue_head(&vcpu->arch.cpu_run); mutex_lock(&kvm->lock); - vcore = kvm->arch.vcores[core]; - if (!vcore) { - vcore = kvmppc_vcore_create(kvm, core); - kvm->arch.vcores[core] = vcore; - kvm->arch.online_vcores++; + vcore = NULL; + err = -EINVAL; + core = id / kvm->arch.smt_mode; + if (core < KVM_MAX_VCORES) { + vcore = kvm->arch.vcores[core]; + if (!vcore) { + err = -ENOMEM; + vcore = kvmppc_vcore_create(kvm, core); + kvm->arch.vcores[core] = vcore; + kvm->arch.online_vcores++; + } } mutex_unlock(&kvm->lock); @@ -1874,6 +1876,40 @@ out: return ERR_PTR(err); } +static int kvmhv_set_smt_mode(struct kvm *kvm, unsigned long smt_mode, + unsigned long flags) +{ + int err; + + if (flags) + return -EINVAL; + if (smt_mode > MAX_SMT_THREADS || !is_power_of_2(smt_mode)) + return -EINVAL; + if (!cpu_has_feature(CPU_FTR_ARCH_300)) { + /* + * On POWER8 (or POWER7), the threading mode is "strict", + * so we pack smt_mode vcpus per vcore. + */ + if (smt_mode > threads_per_subcore) + return -EINVAL; + } else { + /* + * On POWER9, the threading mode is "loose", + * so each vcpu gets its own vcore. + */ + smt_mode = 1; + } + mutex_lock(&kvm->lock); + err = -EBUSY; + if (!kvm->arch.online_vcores) { + kvm->arch.smt_mode = smt_mode; + err = 0; + } + mutex_unlock(&kvm->lock); + + return err; +} + static void unpin_vpa(struct kvm *kvm, struct kvmppc_vpa *vpa) { if (vpa->pinned_addr) @@ -3554,6 +3590,18 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm) kvm_hv_vm_activated(); /* + * Initialize smt_mode depending on processor. + * POWER8 and earlier have to use "strict" threading, where + * all vCPUs in a vcore have to run on the same (sub)core, + * whereas on POWER9 the threads can each run a different + * guest. + */ + if (!cpu_has_feature(CPU_FTR_ARCH_300)) + kvm->arch.smt_mode = threads_per_subcore; + else + kvm->arch.smt_mode = 1; + + /* * Create a debugfs directory for the VM */ snprintf(buf, sizeof(buf), "vm%d", current->pid); @@ -3982,6 +4030,7 @@ static struct kvmppc_ops kvm_ops_hv = { #endif .configure_mmu = kvmhv_configure_mmu, .get_rmmu_info = kvmhv_get_rmmu_info, + .set_smt_mode = kvmhv_set_smt_mode, }; static int kvm_init_subcore_bitmap(void) diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 7f71ab5fcad1..da90ae8cd508 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -554,7 +554,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE case KVM_CAP_PPC_SMT: r = 0; - if (hv_enabled) { + if (kvm) + r = kvm->arch.smt_mode; + else if (hv_enabled) { if (cpu_has_feature(CPU_FTR_ARCH_300)) r = 1; else @@ -1712,6 +1714,15 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, r = 0; break; } + case KVM_CAP_PPC_SMT: { + unsigned long mode = cap->args[0]; + unsigned long flags = cap->args[1]; + + r = -EINVAL; + if (kvm->arch.kvm_ops->set_smt_mode) + r = kvm->arch.kvm_ops->set_smt_mode(kvm, mode, flags); + break; + } #endif default: r = -EINVAL; |