KVM: arm64: Add HYP interface to flush VM Stage 1/2 TLB entries

This patch adds support for arm64 hyp interface to flush all TLBs associated
with VMID.
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMario Smarduch <m.smarduch@samsung.com>

arch/arm64/kvm/hyp.S

@@ -1030,6 +1030,28 @@ ENTRY(__kvm_tlb_flush_vmid_ipa)
 	ret
 ENDPROC(__kvm_tlb_flush_vmid_ipa)
 
+/**
+ * void __kvm_tlb_flush_vmid(struct kvm *kvm) - Flush per-VMID TLBs
+ * @struct kvm *kvm - pointer to kvm structure
+ *
+ * Invalidates all Stage 1 and 2 TLB entries for current VMID.
+ */
+ENTRY(__kvm_tlb_flush_vmid)
+	dsb     ishst
+
+	kern_hyp_va     x0
+	ldr     x2, [x0, #KVM_VTTBR]
+	msr     vttbr_el2, x2
+	isb
+
+	tlbi    vmalls12e1is
+	dsb     ish
+	isb
+
+	msr     vttbr_el2, xzr
+	ret
+ENDPROC(__kvm_tlb_flush_vmid)
+
 ENTRY(__kvm_flush_vm_context)
 	dsb	ishst
 	tlbi	alle1is