diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 19b6942c6969..fff391b9b97b 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -378,6 +378,10 @@ static inline unsigned long compute_tlbie_rb(unsigned long v, unsigned long r,
 		rb |= 1;		/* L field */
 		rb |= r & 0xff000 & ((1ul << a_pgshift) - 1); /* LP field */
 	}
+	/*
+	 * This sets both bits of the B field in the PTE. 0b1x values are
+	 * reserved, but those will have been filtered by kvmppc_do_h_enter.
+	 */
 	rb |= (v >> HPTE_V_SSIZE_SHIFT) << 8;	/* B field */
 	return rb;
 }
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index 632b2545072b..2c1f3c6e72d1 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -207,6 +207,15 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
 
 	if (kvm_is_radix(kvm))
 		return H_FUNCTION;
+	/*
+	 * The HPTE gets used by compute_tlbie_rb() to set TLBIE bits, so
+	 * these functions should work together -- must ensure a guest can not
+	 * cause problems with the TLBIE that KVM executes.
+	 */
+	if ((pteh >> HPTE_V_SSIZE_SHIFT) & 0x2) {
+		/* B=0b1x is a reserved value, disallow it. */
+		return H_PARAMETER;
+	}
 	psize = kvmppc_actual_pgsz(pteh, ptel);
 	if (!psize)
 		return H_PARAMETER;