KVM: x86/mmu: Re-add const qualifier in kvm_tdp_mmu_zap_collapsible_sptes

kvm_tdp_mmu_zap_collapsible_sptes unnecessarily removes the const
qualifier from its memlsot argument, leading to a compiler warning. Add
the const annotation and pass it to subsequent functions.
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20210401233736.638171-2-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu/mmu.c

@@ -715,8 +715,7 @@ static void kvm_mmu_page_set_gfn(struct kvm_mmu_page *sp, int index, gfn_t gfn)
  * handling slots that are not large page aligned.
  */
 static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn,
-					      struct kvm_memory_slot *slot,
-					      int level)
+		const struct kvm_memory_slot *slot, int level)
 {
 	unsigned long idx;
 
@@ -2702,7 +2701,7 @@ static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep)
 }
 
 static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn,
-				  struct kvm_memory_slot *slot)
+				  const struct kvm_memory_slot *slot)
 {
 	unsigned long hva;
 	pte_t *pte;
@@ -2728,8 +2727,9 @@ static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn,
 	return level;
 }
 
-int kvm_mmu_max_mapping_level(struct kvm *kvm, struct kvm_memory_slot *slot,
-			      gfn_t gfn, kvm_pfn_t pfn, int max_level)
+int kvm_mmu_max_mapping_level(struct kvm *kvm,
+			      const struct kvm_memory_slot *slot, gfn_t gfn,
+			      kvm_pfn_t pfn, int max_level)
 {
 	struct kvm_lpage_info *linfo;
 

arch/x86/kvm/mmu/mmu_internal.h

@@ -161,8 +161,9 @@ enum {
 #define SET_SPTE_NEED_REMOTE_TLB_FLUSH	BIT(1)
 #define SET_SPTE_SPURIOUS		BIT(2)
 
-int kvm_mmu_max_mapping_level(struct kvm *kvm, struct kvm_memory_slot *slot,
-			      gfn_t gfn, kvm_pfn_t pfn, int max_level);
+int kvm_mmu_max_mapping_level(struct kvm *kvm,
+			      const struct kvm_memory_slot *slot, gfn_t gfn,
+			      kvm_pfn_t pfn, int max_level);
 int kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, gfn_t gfn,
 			    int max_level, kvm_pfn_t *pfnp,
 			    bool huge_page_disallowed, int *req_level);

arch/x86/kvm/mmu/tdp_mmu.c

@@ -1190,7 +1190,7 @@ void kvm_tdp_mmu_clear_dirty_pt_masked(struct kvm *kvm,
  */
 static bool zap_collapsible_spte_range(struct kvm *kvm,
 				       struct kvm_mmu_page *root,
-				       struct kvm_memory_slot *slot,
+				       const struct kvm_memory_slot *slot,
 				       bool flush)
 {
 	gfn_t start = slot->base_gfn;
@@ -1231,7 +1231,8 @@ static bool zap_collapsible_spte_range(struct kvm *kvm,
  * be replaced by large mappings, for GFNs within the slot.
  */
 bool kvm_tdp_mmu_zap_collapsible_sptes(struct kvm *kvm,
-				       struct kvm_memory_slot *slot, bool flush)
+				       const struct kvm_memory_slot *slot,
+				       bool flush)
 {
 	struct kvm_mmu_page *root;
 

arch/x86/kvm/mmu/tdp_mmu.h

@@ -53,7 +53,8 @@ void kvm_tdp_mmu_clear_dirty_pt_masked(struct kvm *kvm,
 				       gfn_t gfn, unsigned long mask,
 				       bool wrprot);
 bool kvm_tdp_mmu_zap_collapsible_sptes(struct kvm *kvm,
-				       struct kvm_memory_slot *slot, bool flush);
+				       const struct kvm_memory_slot *slot,
+				       bool flush);
 
 bool kvm_tdp_mmu_write_protect_gfn(struct kvm *kvm,
 				   struct kvm_memory_slot *slot, gfn_t gfn);

include/linux/kvm_host.h

@@ -1130,7 +1130,7 @@ __gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn)
 }
 
 static inline unsigned long
-__gfn_to_hva_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
+__gfn_to_hva_memslot(const struct kvm_memory_slot *slot, gfn_t gfn)
 {
 	return slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE;
 }