[PATCH v1 5/6] KVM: selftests: Test for KVM_CAP_INJECT_EXT_IABT

[Jiaqi Yan]

Test userspace can use KVM_SET_VCPU_EVENTS to inject an external
instruction abort into guest. The test injects instruction abort at an
arbitrary time without real SEA happening in the guest VCPU, so only
certain ESR_EL1 value can be expected, but not the case for FAR_EL1.

Signed-off-by: Jiaqi Yan <jiaqiyan at google.com>
---
 tools/arch/arm64/include/uapi/asm/kvm.h       |   3 +-
 tools/testing/selftests/kvm/Makefile.kvm      |   1 +
 .../testing/selftests/kvm/arm64/inject_iabt.c | 100 ++++++++++++++++++
 3 files changed, 103 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/kvm/arm64/inject_iabt.c

diff --git a/tools/arch/arm64/include/uapi/asm/kvm.h b/tools/arch/arm64/include/uapi/asm/kvm.h
index af9d9acaf9975..d3a4530846311 100644
--- a/tools/arch/arm64/include/uapi/asm/kvm.h
+++ b/tools/arch/arm64/include/uapi/asm/kvm.h
@@ -184,8 +184,9 @@ struct kvm_vcpu_events {
 		__u8 serror_pending;
 		__u8 serror_has_esr;
 		__u8 ext_dabt_pending;
+		__u8 ext_iabt_pending;
 		/* Align it to 8 bytes */
-		__u8 pad[5];
+		__u8 pad[4];
 		__u64 serror_esr;
 	} exception;
 	__u32 reserved[12];
diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
index 16d2e9f32619f..708fd126a36dd 100644
--- a/tools/testing/selftests/kvm/Makefile.kvm
+++ b/tools/testing/selftests/kvm/Makefile.kvm
@@ -148,6 +148,7 @@ TEST_GEN_PROGS_arm64 += arm64/aarch32_id_regs
 TEST_GEN_PROGS_arm64 += arm64/arch_timer_edge_cases
 TEST_GEN_PROGS_arm64 += arm64/debug-exceptions
 TEST_GEN_PROGS_arm64 += arm64/hypercalls
+TEST_GEN_PROGS_arm64 += arm64/inject_iabt
 TEST_GEN_PROGS_arm64 += arm64/mmio_abort
 TEST_GEN_PROGS_arm64 += arm64/page_fault_test
 TEST_GEN_PROGS_arm64 += arm64/psci_test
diff --git a/tools/testing/selftests/kvm/arm64/inject_iabt.c b/tools/testing/selftests/kvm/arm64/inject_iabt.c
new file mode 100644
index 0000000000000..43b701e9143c2
--- /dev/null
+++ b/tools/testing/selftests/kvm/arm64/inject_iabt.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * inject_iabt.c - Tests for injecting instruction aborts into guest.
+ */
+
+#include "processor.h"
+#include "test_util.h"
+
+static void expect_iabt_handler(struct ex_regs *regs)
+{
+	u64 esr = read_sysreg(esr_el1);
+
+	GUEST_PRINTF("Guest SEA esr_el1=%#lx\n", esr);
+	GUEST_ASSERT_EQ(ESR_ELx_EC(esr), ESR_ELx_EC_IABT_CUR);
+	GUEST_ASSERT_EQ(esr & ESR_ELx_FSC_TYPE, ESR_ELx_FSC_EXTABT);
+	/*
+	 * We inject IABT but there is no SEA in guest at all,
+	 * so guest should see FnV == 1, which is set by KVM.
+	 */
+	GUEST_ASSERT(esr & ESR_ELx_FnV);
+
+	GUEST_DONE();
+}
+
+static void guest_code(void)
+{
+	GUEST_FAIL("Guest should only run SEA handler");
+}
+
+static void vcpu_run_expect_done(struct kvm_vcpu *vcpu)
+{
+	struct ucall uc;
+	bool guest_done = false;
+
+	do {
+		vcpu_run(vcpu);
+		switch (get_ucall(vcpu, &uc)) {
+		case UCALL_ABORT:
+			REPORT_GUEST_ASSERT(uc);
+			break;
+		case UCALL_PRINTF:
+			ksft_print_msg("From guest: %s", uc.buffer);
+		case UCALL_DONE:
+			ksft_print_msg("Guest done gracefully!\n");
+			guest_done = true;
+			break;
+		default:
+			TEST_FAIL("Unexpected ucall: %lu", uc.cmd);
+	}
+	} while (!guest_done);
+}
+
+static void vcpu_inject_ext_iabt(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_events events = {};
+
+	events.exception.ext_iabt_pending = true;
+	vcpu_events_set(vcpu, &events);
+}
+
+static void vcpu_inject_invalid_abt(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_events events = {};
+	int r;
+
+	events.exception.ext_iabt_pending = true;
+	events.exception.ext_dabt_pending = true;
+
+	ksft_print_msg("Injecting invalid external abort events\n");
+	r = __vcpu_ioctl(vcpu, KVM_SET_VCPU_EVENTS, &events);
+	TEST_ASSERT(r && errno == EINVAL,
+		    KVM_IOCTL_ERROR(KVM_SET_VCPU_EVENTS, r));
+}
+
+static void test_inject_iabt(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+
+	vm_init_descriptor_tables(vm);
+	vcpu_init_descriptor_tables(vcpu);
+
+	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
+				ESR_ELx_EC_IABT_CUR, expect_iabt_handler);
+
+	vcpu_inject_invalid_abt(vcpu);
+
+	vcpu_inject_ext_iabt(vcpu);
+	vcpu_run_expect_done(vcpu);
+
+	kvm_vm_free(vm);
+}
+
+int main(void)
+{
+	test_inject_iabt();
+	return 0;
+}
-- 
2.49.0.967.g6a0df3ecc3-goog