Walk the guest page tables via a loop when creating new mappings, instead of using unique variables for each level of the page tables.
This simplifies the code and makes it easier to support 5-level paging in the future.
Signed-off-by: Jim Mattson jmattson@google.com --- .../testing/selftests/kvm/lib/x86/processor.c | 22 +++++++------------ 1 file changed, 8 insertions(+), 14 deletions(-)
diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c index d4c19ac885a9..0238e674709d 100644 --- a/tools/testing/selftests/kvm/lib/x86/processor.c +++ b/tools/testing/selftests/kvm/lib/x86/processor.c @@ -184,8 +184,8 @@ static uint64_t *virt_create_upper_pte(struct kvm_vm *vm, void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level) { const uint64_t pg_size = PG_LEVEL_SIZE(level); - uint64_t *pml4e, *pdpe, *pde; - uint64_t *pte; + uint64_t *pte = &vm->pgd; + int current_level;
TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Unknown or unsupported guest mode, mode: 0x%x", vm->mode); @@ -209,20 +209,14 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, int level) * Allocate upper level page tables, if not already present. Return * early if a hugepage was created. */ - pml4e = virt_create_upper_pte(vm, &vm->pgd, vaddr, paddr, PG_LEVEL_512G, level); - if (*pml4e & PTE_LARGE_MASK) - return; - - pdpe = virt_create_upper_pte(vm, pml4e, vaddr, paddr, PG_LEVEL_1G, level); - if (*pdpe & PTE_LARGE_MASK) - return; - - pde = virt_create_upper_pte(vm, pdpe, vaddr, paddr, PG_LEVEL_2M, level); - if (*pde & PTE_LARGE_MASK) - return; + for (current_level = vm->pgtable_levels; current_level > 0; current_level--) { + pte = virt_create_upper_pte(vm, pte, vaddr, paddr, current_level, level); + if (*pte & PTE_LARGE_MASK) + return; + }
/* Fill in page table entry. */ - pte = virt_get_pte(vm, pde, vaddr, PG_LEVEL_4K); + pte = virt_get_pte(vm, pte, vaddr, PG_LEVEL_4K); TEST_ASSERT(!(*pte & PTE_PRESENT_MASK), "PTE already present for 4k page at vaddr: 0x%lx", vaddr); *pte = PTE_PRESENT_MASK | PTE_WRITABLE_MASK | (paddr & PHYSICAL_PAGE_MASK);