[PATCH 5/9] KVM: X86: Introduce kvm_mmu_slot_lpages() helpers

[Peter Xu]

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@xxxxxxxxxx>
---
 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 4aa3cc6ae5d4..d2acbea2f3b5 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -269,6 +269,20 @@ 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.
@@ -10933,8 +10947,7 @@ static int kvm_alloc_memslot_metadata(struct kvm_memory_slot *slot,
 		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);
 
 		slot->arch.rmap[i] =
 			kvcalloc(lpages, sizeof(*slot->arch.rmap[i]),
-- 
2.31.1