1 files changed, 98 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_extended_hypercalls.c b/tools/testing/selftests/kvm/x86_64/hyperv_extended_hypercalls.c
new file mode 100644
index 000000000000..949e08e98f31
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/hyperv_extended_hypercalls.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Test Hyper-V extended hypercall, HV_EXT_CALL_QUERY_CAPABILITIES (0x8001),
+ * exit to userspace and receive result in guest.
+ *
+ * Negative tests are present in hyperv_features.c
+ *
+ * Copyright 2022 Google LLC
+ * Author: Vipin Sharma <vipinsh@google.com>
+ */
+#include "kvm_util.h"
+#include "processor.h"
+#include "hyperv.h"
+
+/* Any value is fine */
+#define EXT_CAPABILITIES 0xbull
+
+static void guest_code(vm_paddr_t in_pg_gpa, vm_paddr_t out_pg_gpa,
+		       vm_vaddr_t out_pg_gva)
+{
+	uint64_t *output_gva;
+
+	wrmsr(HV_X64_MSR_GUEST_OS_ID, HYPERV_LINUX_OS_ID);
+	wrmsr(HV_X64_MSR_HYPERCALL, in_pg_gpa);
+
+	output_gva = (uint64_t *)out_pg_gva;
+
+	hyperv_hypercall(HV_EXT_CALL_QUERY_CAPABILITIES, in_pg_gpa, out_pg_gpa);
+
+	/* TLFS states output will be a uint64_t value */
+	GUEST_ASSERT_EQ(*output_gva, EXT_CAPABILITIES);
+
+	GUEST_DONE();
+}
+
+int main(void)
+{
+	vm_vaddr_t hcall_out_page;
+	vm_vaddr_t hcall_in_page;
+	struct kvm_vcpu *vcpu;
+	struct kvm_run *run;
+	struct kvm_vm *vm;
+	uint64_t *outval;
+	struct ucall uc;
+
+	TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_CPUID));
+
+	/* Verify if extended hypercalls are supported */
+	if (!kvm_cpuid_has(kvm_get_supported_hv_cpuid(),
+			   HV_ENABLE_EXTENDED_HYPERCALLS)) {
+		print_skip("Extended calls not supported by the kernel");
+		exit(KSFT_SKIP);
+	}
+
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+	run = vcpu->run;
+	vcpu_set_hv_cpuid(vcpu);
+
+	/* Hypercall input */
+	hcall_in_page = vm_vaddr_alloc_pages(vm, 1);
+	memset(addr_gva2hva(vm, hcall_in_page), 0x0, vm->page_size);
+
+	/* Hypercall output */
+	hcall_out_page = vm_vaddr_alloc_pages(vm, 1);
+	memset(addr_gva2hva(vm, hcall_out_page), 0x0, vm->page_size);
+
+	vcpu_args_set(vcpu, 3, addr_gva2gpa(vm, hcall_in_page),
+		      addr_gva2gpa(vm, hcall_out_page), hcall_out_page);
+
+	vcpu_run(vcpu);
+
+	TEST_ASSERT(run->exit_reason == KVM_EXIT_HYPERV,
+		    "Unexpected exit reason: %u (%s)",
+		    run->exit_reason, exit_reason_str(run->exit_reason));
+
+	outval = addr_gpa2hva(vm, run->hyperv.u.hcall.params[1]);
+	*outval = EXT_CAPABILITIES;
+	run->hyperv.u.hcall.result = HV_STATUS_SUCCESS;
+
+	vcpu_run(vcpu);
+
+	TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
+		    "Unexpected exit reason: %u (%s)",
+		    run->exit_reason, exit_reason_str(run->exit_reason));
+
+	switch (get_ucall(vcpu, &uc)) {
+	case UCALL_ABORT:
+		REPORT_GUEST_ASSERT(uc);
+		break;
+	case UCALL_DONE:
+		break;
+	default:
+		TEST_FAIL("Unhandled ucall: %ld", uc.cmd);
+	}
+
+	kvm_vm_free(vm);
+	return 0;
+}