[PATCH] bad bad bad

[Oliver Upton <oliver.upton@linux.dev>]

From: Marc Zyngier <maz@kernel.org>

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 .../selftests/kvm/arm64/external_aborts.c     | 54 +++++++++++++++++++
 .../selftests/kvm/include/arm64/processor.h   |  1 +
 .../selftests/kvm/lib/arm64/processor.c       | 13 ++++-
 3 files changed, 67 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/arm64/external_aborts.c b/tools/testing/selftests/kvm/arm64/external_aborts.c
index 062bf84cced13..780e2af1f3b7b 100644
--- a/tools/testing/selftests/kvm/arm64/external_aborts.c
+++ b/tools/testing/selftests/kvm/arm64/external_aborts.c
@@ -11,6 +11,7 @@
 #define EXPECTED_SERROR_ISS	(ESR_ELx_ISV | 0x1d1ed)
 
 static u64 expected_abort_pc;
+static vm_vaddr_t bad_ptw_va;
 
 static void expect_sea_handler(struct ex_regs *regs)
 {
@@ -84,6 +85,9 @@ static void __vcpu_run_expect(struct kvm_vcpu *vcpu, unsigned int cmd)
 	case UCALL_ABORT:
 		REPORT_GUEST_ASSERT(uc);
 		break;
+	case UCALL_PRINTF:
+		printf("%s", uc.buffer);
+		break;
 	default:
 		if (uc.cmd == cmd)
 			return;
@@ -250,6 +254,55 @@ static void test_serror(void)
 	kvm_vm_free(vm);
 }
 
+static void expect_sea_s1ptw_handler(struct ex_regs *regs)
+{
+	u64 esr = read_sysreg(esr_el1);
+
+
+	GUEST_ASSERT_EQ(regs->pc, expected_abort_pc);
+	GUEST_ASSERT_EQ(ESR_ELx_EC(esr), ESR_ELx_EC_DABT_CUR);
+	__GUEST_ASSERT((esr & ESR_ELx_FSC_TYPE) >= ESR_ELx_FSC_SEA_TTW(-1) &&
+		       (esr & ESR_ELx_FSC_TYPE) <= ESR_ELx_FSC_SEA_TTW(3),
+		       "ESR == %lx\n", esr);
+
+	GUEST_DONE();
+}
+
+static noinline void test_s1ptw_abort_guest(void)
+{
+	void (*fn)(void) = (void*)bad_ptw_va;
+	extern char test_s1ptw_abort_insn;
+
+	WRITE_ONCE(expected_abort_pc, (u64)&test_s1ptw_abort_insn);
+
+	fn();
+	asm volatile("test_s1ptw_abort_insn:\n\t"
+		     "ldr x0, [%0]\n\t"
+		     : : "r" (bad_ptw_va) : "x0", "memory");
+
+	GUEST_FAIL("Load on S1PTW abort should not retire");
+}
+
+static void test_s1ptw_abort(void)
+{
+	struct kvm_vcpu *vcpu;
+	u64 *ptep, bad_pa;
+	struct kvm_vm *vm = vm_create_with_dabt_handler(&vcpu, test_s1ptw_abort_guest,
+							expect_sea_s1ptw_handler);
+
+	bad_ptw_va = __vm_vaddr_alloc(vm, vm->page_size,
+				      vm->page_size, MEM_REGION_DATA);
+
+	ptep = virt_get_pte_hva_at_level(vm, bad_ptw_va, 2);
+	bad_pa = BIT(vm->pa_bits) - vm->page_size;
+
+	*ptep &= ~GENMASK(47, 12);
+	*ptep |= bad_pa;
+
+	vcpu_run_expect_done(vcpu);
+	kvm_vm_free(vm);
+}
+
 static void test_serror_emulated_guest(void)
 {
 	GUEST_ASSERT(!(read_sysreg(isr_el1) & ISR_EL1_A));
@@ -327,4 +380,5 @@ int main(void)
 	test_serror_masked();
 	test_serror_emulated();
 	test_mmio_ease();
+	test_s1ptw_abort();
 }
diff --git a/tools/testing/selftests/kvm/include/arm64/processor.h b/tools/testing/selftests/kvm/include/arm64/processor.h
index 255fed769a8a5..e3e916b1d9c4e 100644
--- a/tools/testing/selftests/kvm/include/arm64/processor.h
+++ b/tools/testing/selftests/kvm/include/arm64/processor.h
@@ -175,6 +175,7 @@ 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);
 
+uint64_t *virt_get_pte_hva_at_level(struct kvm_vm *vm, vm_vaddr_t gva, int level);
 uint64_t *virt_get_pte_hva(struct kvm_vm *vm, vm_vaddr_t gva);
 
 static inline void cpu_relax(void)
diff --git a/tools/testing/selftests/kvm/lib/arm64/processor.c b/tools/testing/selftests/kvm/lib/arm64/processor.c
index 9d69904cb6084..628c5bc8c4381 100644
--- a/tools/testing/selftests/kvm/lib/arm64/processor.c
+++ b/tools/testing/selftests/kvm/lib/arm64/processor.c
@@ -185,7 +185,7 @@ void virt_arch_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
 	_virt_pg_map(vm, vaddr, paddr, attr_idx);
 }
 
-uint64_t *virt_get_pte_hva(struct kvm_vm *vm, vm_vaddr_t gva)
+uint64_t *virt_get_pte_hva_at_level(struct kvm_vm *vm, vm_vaddr_t gva, int level)
 {
 	uint64_t *ptep;
 
@@ -195,17 +195,23 @@ uint64_t *virt_get_pte_hva(struct kvm_vm *vm, vm_vaddr_t gva)
 	ptep = addr_gpa2hva(vm, vm->pgd) + pgd_index(vm, gva) * 8;
 	if (!ptep)
 		goto unmapped_gva;
+	if (level == 0)
+		return ptep;
 
 	switch (vm->pgtable_levels) {
 	case 4:
 		ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pud_index(vm, gva) * 8;
 		if (!ptep)
 			goto unmapped_gva;
+		if (level == 1)
+			return ptep;
 		/* fall through */
 	case 3:
 		ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pmd_index(vm, gva) * 8;
 		if (!ptep)
 			goto unmapped_gva;
+		if (level == 2)
+			return ptep;
 		/* fall through */
 	case 2:
 		ptep = addr_gpa2hva(vm, pte_addr(vm, *ptep)) + pte_index(vm, gva) * 8;
@@ -223,6 +229,11 @@ uint64_t *virt_get_pte_hva(struct kvm_vm *vm, vm_vaddr_t gva)
 	exit(EXIT_FAILURE);
 }
 
+uint64_t *virt_get_pte_hva(struct kvm_vm *vm, vm_vaddr_t gva)
+{
+	return virt_get_pte_hva_at_level(vm, gva, 3);
+}
+
 vm_paddr_t addr_arch_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
 {
 	uint64_t *ptep = virt_get_pte_hva(vm, gva);
-- 
2.39.2