[PATCH 10/12] KVM: selftests: Move EPT-specific init outside nested_create_pte()

Yosry Ahmed
2025-10-01T14:58:59Z

From: Yosry Ahmed <yosryahmed@google.com>

Refactor the EPT specific initialization into nested_ept_create_pte(),
in preparation for making nested_create_pte() NPT-friendly.

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
---
tools/testing/selftests/kvm/lib/x86/vmx.c | 71 ++++++++++++++---------
1 file changed, 43 insertions(+), 28 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/x86/vmx.c b/tools/testing/selftests/kvm/lib/x86/vmx.c
index b0e6267eac806..eeacf42bf30b1 100644
--- a/tools/testing/selftests/kvm/lib/x86/vmx.c
+++ b/tools/testing/selftests/kvm/lib/x86/vmx.c
@@ -365,46 +365,61 @@ void prepare_vmcs(struct vmx_pages *vmx, void *guest_rip, void *guest_rsp)
init_vmcs_guest_state(guest_rip, guest_rsp);
}

+static bool nested_ept_create_pte(struct kvm_vm *vm,
+ uint64_t *pte,
+ uint64_t paddr,
+ uint64_t *address,
+ bool *leaf)
+{
+ struct eptPageTableEntry *epte = (struct eptPageTableEntry *)pte;
+
+ /* PTE already exists? */
+ if (epte->readable) {
+ *leaf = epte->page_size;
+ *address = epte->address;
+ return false;
+ }
+
+ epte->writable = true;
+ epte->readable = true;
+ epte->executable = true;
+ epte->page_size = *leaf;
+
+ if (*leaf)
+ epte->address = paddr >> vm->page_shift;
+ else
+ epte->address = vm_alloc_page_table(vm) >> vm->page_shift;
+
+ *address = epte->address;
+
+ /*
+ * For now mark these as accessed and dirty because the only
+ * testcase we have needs that. Can be reconsidered later.
+ */
+ epte->accessed = *leaf;
+ epte->dirty = *leaf;
+ return true;
+}
+
static uint64_t nested_create_pte(struct kvm_vm *vm,
uint64_t *pte,
uint64_t nested_paddr,
uint64_t paddr,
int level,
- bool leaf)
+ bool want_leaf)
{
- struct eptPageTableEntry *epte = (struct eptPageTableEntry *)pte;
-
- if (!epte->readable) {
- epte->writable = true;
- epte->readable = true;
- epte->executable = true;
- epte->page_size = leaf;
+ bool leaf = want_leaf;
+ uint64_t address;

- if (leaf)
- epte->address = paddr >> vm->page_shift;
- else
- epte->address = vm_alloc_page_table(vm) >> vm->page_shift;
-
- /*
- * For now mark these as accessed and dirty because the only
- * testcase we have needs that. Can be reconsidered later.
- */
- epte->accessed = leaf;
- epte->dirty = leaf;
- } else {
- /*
- * Entry already present. Assert that the caller doesn't want a
- * leaf entry at this level, and that there isn't a leaf entry
- * at this level.
- */
- TEST_ASSERT(!leaf,
+ if (!nested_ept_create_pte(vm, pte, paddr, &address, &leaf)) {
+ TEST_ASSERT(!want_leaf,
"Cannot create leaf entry at level: %u, nested_paddr: 0x%lx",
level, nested_paddr);
- TEST_ASSERT(!epte->page_size,
+ TEST_ASSERT(!leaf,
"Leaf entry already exists at level: %u, nested_paddr: 0x%lx",
level, nested_paddr);
}
- return epte->address;
+ return address;
}

--
2.51.0.618.g983fd99d29-goog