KVM: arm64: Make the hyp memory pool static

The hyp memory pool struct is sized to fit exactly the needs of the
hypervisor stage-1 page-table allocator, so it is important it is not
used for anything else. As it is currently used only from setup.c,
reduce its visibility by marking it static.
Signed-off-by: Quentin Perret <qperret@google.com>
Reviewed-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211208152300.2478542-4-qperret@google.com

arch/arm64/kvm/hyp/include/nvhe/mm.h

@@ -15,7 +15,6 @@ extern struct memblock_region kvm_nvhe_sym(hyp_memory)[];
 extern unsigned int kvm_nvhe_sym(hyp_memblock_nr);
 extern struct kvm_pgtable pkvm_pgtable;
 extern hyp_spinlock_t pkvm_pgd_lock;
-extern struct hyp_pool hpool;
 extern u64 __io_map_base;
 
 int hyp_create_idmap(u32 hyp_va_bits);

arch/arm64/kvm/hyp/nvhe/setup.c

@@ -17,7 +17,6 @@
 #include <nvhe/mm.h>
 #include <nvhe/trap_handler.h>
 
-struct hyp_pool hpool;
 unsigned long hyp_nr_cpus;
 
 #define hyp_percpu_size ((unsigned long)__per_cpu_end - \
@@ -27,6 +26,7 @@ static void *vmemmap_base;
 static void *hyp_pgt_base;
 static void *host_s2_pgt_base;
 static struct kvm_pgtable_mm_ops pkvm_pgtable_mm_ops;
+static struct hyp_pool hpool;
 
 static int divide_memory_pool(void *virt, unsigned long size)
 {