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 <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This commit is contained in:
David Hildenbrand 2016-04-04 13:59:42 +02:00 committed by Christian Borntraeger
parent 9bb0ec0997
commit 053dd2308d
1 changed files with 11 additions and 1 deletions

View File

@ -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