[PATCH v3 3/7] KVM: X86: Introduce kvm_mmu_slot_lpages() helpers

[Peter Xu <peterx@redhat.com>]

Introduce kvm_mmu_slot_lpages() to calculcate lpage_info and rmap array size.
The other __kvm_mmu_slot_lpages() can take an extra parameter of npages rather
than fetching from the memslot pointer.  Start to use the latter one in
kvm_alloc_memslot_metadata().

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 arch/x86/kvm/x86.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 916c976e99ab..e44d8f7781b6 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -299,6 +299,20 @@ static struct kmem_cache *x86_fpu_cache;
 
 static struct kmem_cache *x86_emulator_cache;
 
+static inline unsigned long
+__kvm_mmu_slot_lpages(struct kvm_memory_slot *slot, unsigned long npages,
+		      int level)
+{
+	return gfn_to_index(slot->base_gfn + npages - 1,
+			    slot->base_gfn, level) + 1;
+}
+
+static inline unsigned long
+kvm_mmu_slot_lpages(struct kvm_memory_slot *slot, int level)
+{
+	return __kvm_mmu_slot_lpages(slot, slot->npages, level);
+}
+
 /*
  * When called, it means the previous get/set msr reached an invalid msr.
  * Return true if we want to ignore/silent this failed msr access.
@@ -11443,8 +11457,7 @@ static int kvm_alloc_memslot_metadata(struct kvm *kvm,
 		int lpages;
 		int level = i + 1;
 
-		lpages = gfn_to_index(slot->base_gfn + npages - 1,
-				      slot->base_gfn, level) + 1;
+		lpages = __kvm_mmu_slot_lpages(slot, npages, level);
 
 		linfo = kvcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT);
 		if (!linfo)
-- 
2.31.1