KVM: PPC: Book3S HV: Add nested shadow page tables to debugfs

This adds a list of valid shadow PTEs for each nested guest to
the 'radix' file for the guest in debugfs.  This can be useful for
debugging.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 15 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index 3f21f785bf0a..401d2ecbebc5 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -1274,3 +1274,18 @@ long int kvmhv_nested_page_fault(struct kvm_vcpu *vcpu)
 	mutex_unlock(&gp->tlb_lock);
 	return ret;
 }
+
+int kvmhv_nested_next_lpid(struct kvm *kvm, int lpid)
+{
+	int ret = -1;
+
+	spin_lock(&kvm->mmu_lock);
+	while (++lpid <= kvm->arch.max_nested_lpid) {
+		if (kvm->arch.nested_guests[lpid]) {
+			ret = lpid;
+			break;
+		}
+	}
+	spin_unlock(&kvm->mmu_lock);
+	return ret;
+}