From ed0b58fc6f0bdde360c28314e0faedc9a0a6c3de Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 6 Oct 2022 00:45:09 +0000 Subject: [PATCH] KVM: selftests: Verify parent PTE is PRESENT when getting child PTE Verify the parent PTE is PRESENT when getting a child via virt_get_pte() so that the helper can be used for getting PTEs/GPAs without losing sanity checks that the walker isn't wandering into the weeds. Signed-off-by: Sean Christopherson Link: https://lore.kernel.org/r/20221006004512.666529-5-seanjc@google.com --- tools/testing/selftests/kvm/lib/x86_64/processor.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index 324bf24564a1..c9649f19aca1 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -131,23 +131,28 @@ void virt_arch_pgd_alloc(struct kvm_vm *vm) } } -static void *virt_get_pte(struct kvm_vm *vm, uint64_t pt_gpa, uint64_t vaddr, - int level) +static void *virt_get_pte(struct kvm_vm *vm, uint64_t *parent_pte, + uint64_t vaddr, int level) { + uint64_t pt_gpa = PTE_GET_PA(*parent_pte); uint64_t *page_table = addr_gpa2hva(vm, pt_gpa); int index = (vaddr >> PG_LEVEL_SHIFT(level)) & 0x1ffu; + TEST_ASSERT((*parent_pte & PTE_PRESENT_MASK) || parent_pte == &vm->pgd, + "Parent PTE (level %d) not PRESENT for gva: 0x%08lx", + level + 1, vaddr); + return &page_table[index]; } static uint64_t *virt_create_upper_pte(struct kvm_vm *vm, - uint64_t pt_gpa, + uint64_t *parent_pte, uint64_t vaddr, uint64_t paddr, int current_level, int target_level) { - uint64_t *pte = virt_get_pte(vm, pt_gpa, vaddr, current_level); + uint64_t *pte = virt_get_pte(vm, parent_pte, vaddr, current_level); if (!(*pte & PTE_PRESENT_MASK)) { *pte = PTE_PRESENT_MASK | PTE_WRITABLE_MASK; @@ -197,20 +202,20 @@ 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); + 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, PTE_GET_PA(*pml4e), vaddr, paddr, PG_LEVEL_1G, level); + 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, PTE_GET_PA(*pdpe), vaddr, paddr, PG_LEVEL_2M, level); + pde = virt_create_upper_pte(vm, pdpe, vaddr, paddr, PG_LEVEL_2M, level); if (*pde & PTE_LARGE_MASK) return; /* Fill in page table entry. */ - pte = virt_get_pte(vm, PTE_GET_PA(*pde), vaddr, PG_LEVEL_4K); + pte = virt_get_pte(vm, pde, vaddr, PG_LEVEL_4K); TEST_ASSERT(!(*pte & PTE_PRESENT_MASK), "PTE already present for 4k page at vaddr: 0x%lx\n", vaddr); *pte = PTE_PRESENT_MASK | PTE_WRITABLE_MASK | (paddr & PHYSICAL_PAGE_MASK); -- 2.11.0