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Commit 053dd230 authored by David Hildenbrand's avatar David Hildenbrand Committed by Christian Borntraeger
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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: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 9bb0ec09

arch/s390/kvm/kvm-s390.c

+11 −1
Original line number Diff line number Diff line
@@ -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;

		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