KVM: Add tlb_remote_flush_with_range callback in kvm_x86_ops

Add flush range call back in the kvm_x86_ops and platform can use it
to register its associated function. The parameter "kvm_tlb_range"
accepts a single range and flush list which contains a list of ranges.

Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index ffb8a85..3639077 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -439,6 +439,11 @@
 	u64 pdptrs[4]; /* pae */
 };
 
+struct kvm_tlb_range {
+	u64 start_gfn;
+	u64 pages;
+};
+
 enum pmc_type {
 	KVM_PMC_GP = 0,
 	KVM_PMC_FIXED,
@@ -1041,6 +1046,8 @@
 
 	void (*tlb_flush)(struct kvm_vcpu *vcpu, bool invalidate_gpa);
 	int  (*tlb_remote_flush)(struct kvm *kvm);
+	int  (*tlb_remote_flush_with_range)(struct kvm *kvm,
+			struct kvm_tlb_range *range);
 
 	/*
 	 * Flush any TLB entries associated with the given GVA.