[PATCH v3 02/13] KVM: selftests: aarch64: Add vm_get_pte_gpa library function

[Ricardo Koller <ricarkol@xxxxxxxxxx>]

Add a library function (in-guest) to get the GPA of the PTE of a
particular GVA.  This will be used in a future commit by a test to clear
and check the AF (access flag) of a particular page.

Signed-off-by: Ricardo Koller <ricarkol@xxxxxxxxxx>
---
 .../selftests/kvm/include/aarch64/processor.h |  2 ++
 .../selftests/kvm/lib/aarch64/processor.c     | 24 +++++++++++++++++--
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
index 8f9f46979a00..caa572d83062 100644
--- a/tools/testing/selftests/kvm/include/aarch64/processor.h
+++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
@@ -125,6 +125,8 @@ void vm_install_exception_handler(struct kvm_vm *vm,
 void vm_install_sync_handler(struct kvm_vm *vm,
 		int vector, int ec, handler_fn handler);
 
+vm_paddr_t vm_get_pte_gpa(struct kvm_vm *vm, vm_vaddr_t gva);
+
 static inline void cpu_relax(void)
 {
 	asm volatile("yield" ::: "memory");
diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c
index 9343d82519b4..ee006d354b79 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c
@@ -139,7 +139,7 @@ void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
 	_virt_pg_map(vm, vaddr, paddr, attr_idx);
 }
 
-vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
+vm_paddr_t vm_get_pte_gpa(struct kvm_vm *vm, vm_vaddr_t gva)
 {
 	uint64_t *ptep;
 
@@ -162,7 +162,7 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
 			goto unmapped_gva;
 		/* fall through */
 	case 2:
-		ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pte_index(vm, gva) * 8;
+		ptep = (uint64_t *)(pte_addr(vm, *ptep) + pte_index(vm, gva) * 8);
 		if (!ptep)
 			goto unmapped_gva;
 		break;
@@ -170,6 +170,26 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
 		TEST_FAIL("Page table levels must be 2, 3, or 4");
 	}
 
+	return (vm_paddr_t)ptep;
+
+unmapped_gva:
+	TEST_FAIL("No mapping for vm virtual address, gva: 0x%lx", gva);
+	exit(1);
+}
+
+vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
+{
+	uint64_t *ptep;
+	vm_paddr_t ptep_gpa;
+
+	ptep_gpa = vm_get_pte_gpa(vm, gva);
+	if (!ptep_gpa)
+		goto unmapped_gva;
+
+	ptep = addr_gpa2hva(vm, ptep_gpa);
+	if (!ptep)
+		goto unmapped_gva;
+
 	return pte_addr(vm, *ptep) + (gva & (vm->page_size - 1));
 
 unmapped_gva:
-- 
2.35.1.1178.g4f1659d476-goog