diff options
Diffstat (limited to 'arch/s390/kvm/kvm-s390.c')
| -rw-r--r-- | arch/s390/kvm/kvm-s390.c | 159 |
1 files changed, 158 insertions, 1 deletions
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 689ac48361c6..c2b391499374 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -31,6 +31,7 @@ #include <linux/bitmap.h> #include <linux/sched/signal.h> +#include <linux/string.h> #include <asm/asm-offsets.h> #include <asm/lowcore.h> #include <asm/stp.h> @@ -750,6 +751,129 @@ static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr) return 0; } +static void kvm_s390_sync_request_broadcast(struct kvm *kvm, int req) +{ + int cx; + struct kvm_vcpu *vcpu; + + kvm_for_each_vcpu(cx, vcpu, kvm) + kvm_s390_sync_request(req, vcpu); +} + +/* + * Must be called with kvm->srcu held to avoid races on memslots, and with + * kvm->lock to avoid races with ourselves and kvm_s390_vm_stop_migration. + */ +static int kvm_s390_vm_start_migration(struct kvm *kvm) +{ + struct kvm_s390_migration_state *mgs; + struct kvm_memory_slot *ms; + /* should be the only one */ + struct kvm_memslots *slots; + unsigned long ram_pages; + int slotnr; + + /* migration mode already enabled */ + if (kvm->arch.migration_state) + return 0; + + slots = kvm_memslots(kvm); + if (!slots || !slots->used_slots) + return -EINVAL; + + mgs = kzalloc(sizeof(*mgs), GFP_KERNEL); + if (!mgs) + return -ENOMEM; + kvm->arch.migration_state = mgs; + + if (kvm->arch.use_cmma) { + /* + * Get the last slot. They should be sorted by base_gfn, so the + * last slot is also the one at the end of the address space. + * We have verified above that at least one slot is present. + */ + ms = slots->memslots + slots->used_slots - 1; + /* round up so we only use full longs */ + ram_pages = roundup(ms->base_gfn + ms->npages, BITS_PER_LONG); + /* allocate enough bytes to store all the bits */ + mgs->pgste_bitmap = vmalloc(ram_pages / 8); + if (!mgs->pgste_bitmap) { + kfree(mgs); + kvm->arch.migration_state = NULL; + return -ENOMEM; + } + + mgs->bitmap_size = ram_pages; + atomic64_set(&mgs->dirty_pages, ram_pages); + /* mark all the pages in active slots as dirty */ + for (slotnr = 0; slotnr < slots->used_slots; slotnr++) { + ms = slots->memslots + slotnr; + bitmap_set(mgs->pgste_bitmap, ms->base_gfn, ms->npages); + } + + kvm_s390_sync_request_broadcast(kvm, KVM_REQ_START_MIGRATION); + } + return 0; +} + +/* + * Must be called with kvm->lock to avoid races with ourselves and + * kvm_s390_vm_start_migration. + */ +static int kvm_s390_vm_stop_migration(struct kvm *kvm) +{ + struct kvm_s390_migration_state *mgs; + + /* migration mode already disabled */ + if (!kvm->arch.migration_state) + return 0; + mgs = kvm->arch.migration_state; + kvm->arch.migration_state = NULL; + + if (kvm->arch.use_cmma) { + kvm_s390_sync_request_broadcast(kvm, KVM_REQ_STOP_MIGRATION); + vfree(mgs->pgste_bitmap); + } + kfree(mgs); + return 0; +} + +static int kvm_s390_vm_set_migration(struct kvm *kvm, + struct kvm_device_attr *attr) +{ + int idx, res = -ENXIO; + + mutex_lock(&kvm->lock); + switch (attr->attr) { + case KVM_S390_VM_MIGRATION_START: + idx = srcu_read_lock(&kvm->srcu); + res = kvm_s390_vm_start_migration(kvm); + srcu_read_unlock(&kvm->srcu, idx); + break; + case KVM_S390_VM_MIGRATION_STOP: + res = kvm_s390_vm_stop_migration(kvm); + break; + default: + break; + } + mutex_unlock(&kvm->lock); + + return res; +} + +static int kvm_s390_vm_get_migration(struct kvm *kvm, + struct kvm_device_attr *attr) +{ + u64 mig = (kvm->arch.migration_state != NULL); + + if (attr->attr != KVM_S390_VM_MIGRATION_STATUS) + return -ENXIO; + + if (copy_to_user((void __user *)attr->addr, &mig, sizeof(mig))) + return -EFAULT; + return 0; +} + static int kvm_s390_set_tod_high(struct kvm *kvm, struct kvm_device_attr *attr) { u8 gtod_high; @@ -1090,6 +1214,9 @@ static int kvm_s390_vm_set_attr(struct kvm *kvm, struct kvm_device_attr *attr) case KVM_S390_VM_CRYPTO: ret = kvm_s390_vm_set_crypto(kvm, attr); break; + case KVM_S390_VM_MIGRATION: + ret = kvm_s390_vm_set_migration(kvm, attr); + break; default: ret = -ENXIO; break; @@ -1112,6 +1239,9 @@ static int kvm_s390_vm_get_attr(struct kvm *kvm, struct kvm_device_attr *attr) case KVM_S390_VM_CPU_MODEL: ret = kvm_s390_get_cpu_model(kvm, attr); break; + case KVM_S390_VM_MIGRATION: + ret = kvm_s390_vm_get_migration(kvm, attr); + break; default: ret = -ENXIO; break; @@ -1179,6 +1309,9 @@ static int kvm_s390_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr) break; } break; + case KVM_S390_VM_MIGRATION: + ret = 0; + break; default: ret = -ENXIO; break; @@ -1633,6 +1766,10 @@ void kvm_arch_destroy_vm(struct kvm *kvm) kvm_s390_destroy_adapters(kvm); kvm_s390_clear_float_irqs(kvm); kvm_s390_vsie_destroy(kvm); + if (kvm->arch.migration_state) { + vfree(kvm->arch.migration_state->pgste_bitmap); + kfree(kvm->arch.migration_state); + } KVM_EVENT(3, "vm 0x%pK destroyed", kvm); } @@ -1977,7 +2114,6 @@ int kvm_s390_vcpu_setup_cmma(struct kvm_vcpu *vcpu) if (!vcpu->arch.sie_block->cbrlo) return -ENOMEM; - vcpu->arch.sie_block->ecb2 |= ECB2_CMMA; vcpu->arch.sie_block->ecb2 &= ~ECB2_PFMFI; return 0; } @@ -2489,6 +2625,27 @@ retry: goto retry; } + if (kvm_check_request(KVM_REQ_START_MIGRATION, vcpu)) { + /* + * Disable CMMA virtualization; we will emulate the ESSA + * instruction manually, in order to provide additional + * functionalities needed for live migration. + */ + vcpu->arch.sie_block->ecb2 &= ~ECB2_CMMA; + goto retry; + } + + if (kvm_check_request(KVM_REQ_STOP_MIGRATION, vcpu)) { + /* + * Re-enable CMMA virtualization if CMMA is available and + * was used. + */ + if ((vcpu->kvm->arch.use_cmma) && + (vcpu->kvm->mm->context.use_cmma)) + vcpu->arch.sie_block->ecb2 |= ECB2_CMMA; + goto retry; + } + /* nothing to do, just clear the request */ kvm_clear_request(KVM_REQ_UNHALT, vcpu); |