KVM: PPC: Book3S HV: Only accept host PVR value for guest PVR

Since the guest can read the machine's PVR (Processor Version Register)
directly and see the real value, we should disallow userspace from
setting any value for the guest's PVR other than the real host value.
Therefore this makes kvm_arch_vcpu_set_sregs_hv() check the supplied
PVR value and return an error if it is different from the host value,
which has been put into vcpu->arch.pvr at vcpu creation time.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Paul Mackerras 2014-09-02 16:14:43 +10:00 коммит произвёл Alexander Graf
Родитель b754c739ee
Коммит 9333e6c4c1
1 изменённых файлов: 3 добавлений и 1 удалений

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@ -856,7 +856,9 @@ static int kvm_arch_vcpu_ioctl_set_sregs_hv(struct kvm_vcpu *vcpu,
{
int i, j;
kvmppc_set_pvr_hv(vcpu, sregs->pvr);
/* Only accept the same PVR as the host's, since we can't spoof it */
if (sregs->pvr != vcpu->arch.pvr)
return -EINVAL;
j = 0;
for (i = 0; i < vcpu->arch.slb_nr; i++) {