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KVM: selftests: Verify parent PTE is PRESENT when getting child PTE

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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 <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006004512.666529-5-seanjc@google.com
This commit is contained in:
Sean Christopherson 2022-10-06 00:45:09 +00:00
parent 91add12d38
commit ed0b58fc6f
1 changed files with 13 additions and 8 deletions
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21
tools/testing/selftests/kvm/lib/x86_64/processor.c
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@ -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);