Commit 9333e6c4 authored Sep 02, 2014 by Paul Mackerras Committed by Alexander Graf Sep 22, 2014

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>

parent b754c739

arch/powerpc/kvm/book3s_hv.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -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++) {