KVM: mmio: cleanup kvm_set_mmio_spte_mask

Just reuse rsvd_bits() inside kvm_set_mmio_spte_mask()
for slightly better code.
Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu.c

@@ -295,11 +295,6 @@ static bool check_mmio_spte(struct kvm *kvm, u64 spte)
 	return likely(kvm_gen == spte_gen);
 }
 
-static inline u64 rsvd_bits(int s, int e)
-{
-	return ((1ULL << (e - s + 1)) - 1) << s;
-}
-
 void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
 		u64 dirty_mask, u64 nx_mask, u64 x_mask)
 {

arch/x86/kvm/mmu.h

@@ -56,6 +56,11 @@
 #define PFERR_RSVD_MASK (1U << PFERR_RSVD_BIT)
 #define PFERR_FETCH_MASK (1U << PFERR_FETCH_BIT)
 
+static inline u64 rsvd_bits(int s, int e)
+{
+	return ((1ULL << (e - s + 1)) - 1) << s;
+}
+
 int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4]);
 void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask);
 

arch/x86/kvm/x86.c

@@ -5569,7 +5569,7 @@ static void kvm_set_mmio_spte_mask(void)
 	 * entry to generate page fault with PFER.RSV = 1.
 	 */
 	 /* Mask the reserved physical address bits. */
-	mask = ((1ull << (51 - maxphyaddr + 1)) - 1) << maxphyaddr;
+	mask = rsvd_bits(maxphyaddr, 51);
 
 	/* Bit 62 is always reserved for 32bit host. */
 	mask |= 0x3ull << 62;