KVM: export __gfn_to_pfn_memslot, drop gfn_to_pfn_async

gfn_to_pfn_async is used in just one place, and because of x86-specific
treatment that place will need to look at the memory slot.  Hence inline
it into try_async_pf and export __gfn_to_pfn_memslot.

The patch also switches the subsequent call to gfn_to_pfn_prot to use
__gfn_to_pfn_memslot.  This is a small optimization.  Finally, remove
the now-unused async argument of __gfn_to_pfn.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu.c

@@ -3511,10 +3511,12 @@ static bool can_do_async_pf(struct kvm_vcpu *vcpu)
 static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
 			 gva_t gva, pfn_t *pfn, bool write, bool *writable)
 {
+	struct kvm_memory_slot *slot;
 	bool async;
 
-	*pfn = gfn_to_pfn_async(vcpu->kvm, gfn, &async, write, writable);
-
+	slot = gfn_to_memslot(vcpu->kvm, gfn);
+	async = false;
+	*pfn = __gfn_to_pfn_memslot(slot, gfn, false, &async, write, writable);
 	if (!async)
 		return false; /* *pfn has correct page already */
 
@@ -3528,8 +3530,7 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
 			return true;
 	}
 
-	*pfn = gfn_to_pfn_prot(vcpu->kvm, gfn, write, writable);
-
+	*pfn = __gfn_to_pfn_memslot(slot, gfn, false, NULL, write, writable);
 	return false;
 }
 

include/linux/kvm_host.h

@@ -539,13 +539,13 @@ void kvm_release_page_dirty(struct page *page);
 void kvm_set_page_accessed(struct page *page);
 
 pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn);
-pfn_t gfn_to_pfn_async(struct kvm *kvm, gfn_t gfn, bool *async,
-		       bool write_fault, bool *writable);
 pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn);
 pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
 		      bool *writable);
 pfn_t gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn);
 pfn_t gfn_to_pfn_memslot_atomic(struct kvm_memory_slot *slot, gfn_t gfn);
+pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool atomic,
+			   bool *async, bool write_fault, bool *writable);
 
 void kvm_release_pfn_clean(pfn_t pfn);
 void kvm_set_pfn_dirty(pfn_t pfn);

virt/kvm/kvm_main.c

@@ -1355,9 +1355,8 @@ exit:
 	return pfn;
 }
 
-static pfn_t
-__gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool atomic,
-		     bool *async, bool write_fault, bool *writable)
+pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool atomic,
+			   bool *async, bool write_fault, bool *writable)
 {
 	unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, write_fault);
 
@@ -1376,44 +1375,35 @@ __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool atomic,
 	return hva_to_pfn(addr, atomic, async, write_fault,
 			  writable);
 }
+EXPORT_SYMBOL_GPL(__gfn_to_pfn_memslot);
 
-static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic, bool *async,
+static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic,
 			  bool write_fault, bool *writable)
 {
 	struct kvm_memory_slot *slot;
 
-	if (async)
-		*async = false;
-
 	slot = gfn_to_memslot(kvm, gfn);
 
-	return __gfn_to_pfn_memslot(slot, gfn, atomic, async, write_fault,
+	return __gfn_to_pfn_memslot(slot, gfn, atomic, NULL, write_fault,
 				    writable);
 }
 
 pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn)
 {
-	return __gfn_to_pfn(kvm, gfn, true, NULL, true, NULL);
+	return __gfn_to_pfn(kvm, gfn, true, true, NULL);
 }
 EXPORT_SYMBOL_GPL(gfn_to_pfn_atomic);
 
-pfn_t gfn_to_pfn_async(struct kvm *kvm, gfn_t gfn, bool *async,
-		       bool write_fault, bool *writable)
-{
-	return __gfn_to_pfn(kvm, gfn, false, async, write_fault, writable);
-}
-EXPORT_SYMBOL_GPL(gfn_to_pfn_async);
-
 pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
 {
-	return __gfn_to_pfn(kvm, gfn, false, NULL, true, NULL);
+	return __gfn_to_pfn(kvm, gfn, false, true, NULL);
 }
 EXPORT_SYMBOL_GPL(gfn_to_pfn);
 
 pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
 		      bool *writable)
 {
-	return __gfn_to_pfn(kvm, gfn, false, NULL, write_fault, writable);
+	return __gfn_to_pfn(kvm, gfn, false, write_fault, writable);
 }
 EXPORT_SYMBOL_GPL(gfn_to_pfn_prot);