KVM: selftests: Move page_align() to shared header

To avoid code duplication, move page_align() to the shared `kvm_util.h`
header file. Rename it to vm_page_align(), to make it clear that the
alignment is done with respect to the guest's base page size.

No functional change intended.

Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260109082218.3236580-5-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>

Author: Fuad Tabba

tools/testing/selftests/kvm/include/kvm_util.h

@@ -1258,6 +1258,11 @@ static inline int __vm_disable_nx_huge_pages(struct kvm_vm *vm)
 	return __vm_enable_cap(vm, KVM_CAP_VM_DISABLE_NX_HUGE_PAGES, 0);
 }
 
+static inline uint64_t vm_page_align(struct kvm_vm *vm, uint64_t v)
+{
+	return (v + vm->page_size - 1) & ~(vm->page_size - 1);
+}
+
 /*
  * Arch hook that is invoked via a constructor, i.e. before exeucting main(),
  * to allow for arch-specific setup that is common to all tests, e.g. computing

tools/testing/selftests/kvm/lib/arm64/processor.c

@@ -21,11 +21,6 @@
 
 static vm_vaddr_t exception_handlers;
 
-static uint64_t page_align(struct kvm_vm *vm, uint64_t v)
-{
-	return (v + vm->page_size - 1) & ~(vm->page_size - 1);
-}
-
 static uint64_t pgd_index(struct kvm_vm *vm, vm_vaddr_t gva)
 {
 	unsigned int shift = (vm->pgtable_levels - 1) * (vm->page_shift - 3) + vm->page_shift;
@@ -115,7 +110,7 @@ static uint64_t __maybe_unused ptrs_per_pte(struct kvm_vm *vm)
 
 void virt_arch_pgd_alloc(struct kvm_vm *vm)
 {
-	size_t nr_pages = page_align(vm, ptrs_per_pgd(vm) * 8) / vm->page_size;
+	size_t nr_pages = vm_page_align(vm, ptrs_per_pgd(vm) * 8) / vm->page_size;
 
 	if (vm->pgd_created)
 		return;

tools/testing/selftests/kvm/lib/riscv/processor.c

@@ -26,11 +26,6 @@ bool __vcpu_has_ext(struct kvm_vcpu *vcpu, uint64_t ext)
 	return !ret && !!value;
 }
 
-static uint64_t page_align(struct kvm_vm *vm, uint64_t v)
-{
-	return (v + vm->page_size - 1) & ~(vm->page_size - 1);
-}
-
 static uint64_t pte_addr(struct kvm_vm *vm, uint64_t entry)
 {
 	return ((entry & PGTBL_PTE_ADDR_MASK) >> PGTBL_PTE_ADDR_SHIFT) <<
@@ -68,7 +63,7 @@ static uint64_t pte_index(struct kvm_vm *vm, vm_vaddr_t gva, int level)
 
 void virt_arch_pgd_alloc(struct kvm_vm *vm)
 {
-	size_t nr_pages = page_align(vm, ptrs_per_pte(vm) * 8) / vm->page_size;
+	size_t nr_pages = vm_page_align(vm, ptrs_per_pte(vm) * 8) / vm->page_size;
 
 	if (vm->pgd_created)
 		return;