Commit ae5b498b authored by Jim Mattson's avatar Jim Mattson Committed by Sean Christopherson
Browse files

KVM: selftests: Use a loop to create guest page tables 



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: default avatarJim Mattson <jmattson@google.com>
Reviewed-by: default avatarYosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20251028225827.2269128-2-jmattson@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent ff736dba

tools/testing/selftests/kvm/lib/x86/processor.c

+11 −14
Original line number Diff line number Diff line
@@ -218,8 +218,8 @@ 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);
@@ -243,20 +243,17 @@ 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)

	for (current_level = vm->pgtable_levels;

	     current_level > PG_LEVEL_4K;

	     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);