From 053dd2308d8174566af4ac0059397c3e4042ebfb Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Mon, 4 Apr 2016 13:59:42 +0200 Subject: [PATCH] KVM: s390: force ibc into valid range Some hardware variants will round the ibc value up/down themselves, others will report a validity intercept. Let's always round it up/down. This patch will also make sure that the ibc is set to 0 in case we don't have ibc support (lowest_ibc == 0). Reviewed-by: Christian Borntraeger Signed-off-by: David Hildenbrand Signed-off-by: Christian Borntraeger --- arch/s390/kvm/kvm-s390.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 0d2f24210198..eb52b3624b41 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -638,6 +638,7 @@ static int kvm_s390_get_tod(struct kvm *kvm, struct kvm_device_attr *attr) static int kvm_s390_set_processor(struct kvm *kvm, struct kvm_device_attr *attr) { struct kvm_s390_vm_cpu_processor *proc; + u16 lowest_ibc, unblocked_ibc; int ret = 0; mutex_lock(&kvm->lock); @@ -653,7 +654,16 @@ static int kvm_s390_set_processor(struct kvm *kvm, struct kvm_device_attr *attr) if (!copy_from_user(proc, (void __user *)attr->addr, sizeof(*proc))) { kvm->arch.model.cpuid = proc->cpuid; - kvm->arch.model.ibc = proc->ibc; + lowest_ibc = sclp.ibc >> 16 & 0xfff; + unblocked_ibc = sclp.ibc & 0xfff; + if (lowest_ibc) { + if (proc->ibc > unblocked_ibc) + kvm->arch.model.ibc = unblocked_ibc; + else if (proc->ibc < lowest_ibc) + kvm->arch.model.ibc = lowest_ibc; + else + kvm->arch.model.ibc = proc->ibc; + } memcpy(kvm->arch.model.fac_list, proc->fac_list, S390_ARCH_FAC_LIST_SIZE_BYTE); } else