[RFC PATCH 3/3] KVM: selftests: Test user hypercalls

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

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
 tools/testing/selftests/kvm/.gitignore        |   1 +
 tools/testing/selftests/kvm/Makefile          |   1 +
 .../selftests/kvm/aarch64/user_hypercalls.c   | 130 ++++++++++++++++++
 3 files changed, 132 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/aarch64/user_hypercalls.c

diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore
index 2f0d705db9db..4f45e987985f 100644
--- a/tools/testing/selftests/kvm/.gitignore
+++ b/tools/testing/selftests/kvm/.gitignore
@@ -5,6 +5,7 @@
 /aarch64/get-reg-list
 /aarch64/hypercalls
 /aarch64/psci_test
+/aarch64/user_hypercalls
 /aarch64/vcpu_width_config
 /aarch64/vgic_init
 /aarch64/vgic_irq
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 0172eb6cb6ee..8ac1988ea669 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -153,6 +153,7 @@ TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions
 TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list
 TEST_GEN_PROGS_aarch64 += aarch64/hypercalls
 TEST_GEN_PROGS_aarch64 += aarch64/psci_test
+TEST_GEN_PROGS_aarch64 += aarch64/user_hypercalls
 TEST_GEN_PROGS_aarch64 += aarch64/vcpu_width_config
 TEST_GEN_PROGS_aarch64 += aarch64/vgic_init
 TEST_GEN_PROGS_aarch64 += aarch64/vgic_irq
diff --git a/tools/testing/selftests/kvm/aarch64/user_hypercalls.c b/tools/testing/selftests/kvm/aarch64/user_hypercalls.c
new file mode 100644
index 000000000000..94ac821c5474
--- /dev/null
+++ b/tools/testing/selftests/kvm/aarch64/user_hypercalls.c
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/arm-smccc.h>
+
+#include "kvm_util.h"
+#include "processor.h"
+#include "test_util.h"
+
+struct test_case {
+	uint64_t	cap;
+	uint32_t	function;
+	uint64_t	args[6];
+};
+
+#define TEST_OWNER(name)							\
+{										\
+	.cap		= BIT_ULL(KVM_ARM_USER_HYPERCALL_OWNER_ ## name),	\
+	.function	= ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,		\
+					     ARM_SMCCC_SMC_32,			\
+					     ARM_SMCCC_OWNER_ ## name,		\
+					     0),				\
+	.args		= {							\
+		__LINE__,							\
+		__LINE__ + 1,							\
+		__LINE__ + 2,							\
+		__LINE__ + 3,							\
+		__LINE__ + 4,							\
+		__LINE__ + 5,							\
+	},									\
+},										\
+{										\
+	.cap		= BIT_ULL(KVM_ARM_USER_HYPERCALL_OWNER_ ## name),	\
+	.function	= ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,		\
+					     ARM_SMCCC_SMC_64,			\
+					     ARM_SMCCC_OWNER_ ## name,		\
+					     0),				\
+	.args		= {							\
+		__LINE__,							\
+		__LINE__ + 1,							\
+		__LINE__ + 2,							\
+		__LINE__ + 3,							\
+		__LINE__ + 4,							\
+		__LINE__ + 5,							\
+	},									\
+}										\
+
+static struct test_case test_cases[] = {
+	TEST_OWNER(ARCH),
+	TEST_OWNER(CPU),
+	TEST_OWNER(SIP),
+	TEST_OWNER(OEM),
+	TEST_OWNER(STANDARD),
+	TEST_OWNER(STANDARD_HYP),
+	TEST_OWNER(VENDOR_HYP),
+	TEST_OWNER(TRUSTED_APP),
+	TEST_OWNER(TRUSTED_OS),
+};
+
+static void guest_main(const struct test_case *test)
+{
+	struct arm_smccc_res unused;
+
+	smccc_hvc(test->function, test->args[0], test->args[1], test->args[2],
+		  test->args[3], test->args[4], test->args[5], 0, &unused);
+
+	GUEST_ASSERT(0);
+}
+
+static void handle_hvc(const struct test_case *test, struct kvm_vcpu *vcpu)
+{
+	struct kvm_run *run = vcpu->run;
+
+	TEST_ASSERT(run->hypercall.nr == test->function,
+		    "unexpected function ID: %llx (expected %x)",
+		    run->hypercall.nr, test->function);
+
+	TEST_ASSERT(!memcmp(&run->hypercall.args, &test->args, sizeof(test->args)),
+		    "unexpected hypercall arguments");
+}
+
+static void handle_ucall(struct kvm_vcpu *vcpu)
+{
+	struct ucall uc;
+
+	switch (get_ucall(vcpu, &uc)) {
+	case UCALL_ABORT:
+		REPORT_GUEST_ASSERT(uc);
+		break;
+	default:
+		TEST_FAIL("unhandled ucall: %lu", uc.cmd);
+	}
+}
+
+static void run_test(const struct test_case *test)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+
+	vm = vm_create_with_one_vcpu(&vcpu, guest_main);
+	vm_enable_cap(vm, KVM_CAP_ARM_USER_HYPERCALLS, test->cap);
+	ucall_init(vm, NULL);
+
+	vcpu_args_set(vcpu, 1, test);
+
+	vcpu_run(vcpu);
+	switch (vcpu->run->exit_reason) {
+	case KVM_EXIT_HYPERCALL:
+		handle_hvc(test, vcpu);
+		break;
+	case KVM_EXIT_MMIO:
+		handle_ucall(vcpu);
+		break;
+	default:
+		TEST_FAIL("unhandled exit reason: %u (%s)", vcpu->run->exit_reason,
+			  exit_reason_str(vcpu->run->exit_reason));
+	}
+
+	ucall_uninit(vm);
+	kvm_vm_free(vm);
+}
+
+int main(void)
+{
+	int i;
+
+	TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_USER_HYPERCALLS));
+
+	for (i = 0; i < ARRAY_SIZE(test_cases); i++)
+		run_test(&test_cases[i]);
+}
-- 
2.38.1.431.g37b22c650d-goog