[PATCH v3 2/6] KVM: x86: Move declaration of kvm_cpu_dirty_log_size() to kvm_dirty_ring.h

[Gavin Shan <gshan@xxxxxxxxxx>]

Not all architectures like ARM64 need to override the function. Move
its declaration to kvm_dirty_ring.h to avoid the following compiling
warning on ARM64 when the feature is enabled.

  arch/arm64/kvm/../../../virt/kvm/dirty_ring.c:14:12:        \
  warning: no previous prototype for 'kvm_cpu_dirty_log_size' \
  [-Wmissing-prototypes]                                      \
  int __weak kvm_cpu_dirty_log_size(void)

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
---
 arch/x86/include/asm/kvm_host.h | 2 --
 arch/x86/kvm/mmu/mmu.c          | 2 ++
 include/linux/kvm_dirty_ring.h  | 1 +
 3 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 2c96c43c313a..4c0fd517282b 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -2082,8 +2082,6 @@ static inline int kvm_cpu_get_apicid(int mps_cpu)
 #define GET_SMSTATE(type, buf, offset)		\
 	(*(type *)((buf) + (offset) - 0x7e00))
 
-int kvm_cpu_dirty_log_size(void);
-
 int memslot_rmap_alloc(struct kvm_memory_slot *slot, unsigned long npages);
 
 #define KVM_CLOCK_VALID_FLAGS						\
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index e418ef3ecfcb..b3eb6a3627ec 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1349,10 +1349,12 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
 		kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
 }
 
+#ifdef CONFIG_HAVE_KVM_DIRTY_RING
 int kvm_cpu_dirty_log_size(void)
 {
 	return kvm_x86_ops.cpu_dirty_log_size;
 }
+#endif
 
 bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,
 				    struct kvm_memory_slot *slot, u64 gfn,
diff --git a/include/linux/kvm_dirty_ring.h b/include/linux/kvm_dirty_ring.h
index 906f899813dc..8c6755981c9b 100644
--- a/include/linux/kvm_dirty_ring.h
+++ b/include/linux/kvm_dirty_ring.h
@@ -71,6 +71,7 @@ static inline bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring)
 
 #else /* CONFIG_HAVE_KVM_DIRTY_RING */
 
+int kvm_cpu_dirty_log_size(void);
 u32 kvm_dirty_ring_get_rsvd_entries(void);
 int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, int index, u32 size);
 
-- 
2.23.0