1 files changed, 143 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/x86/xen_vmcall_test.c b/tools/testing/selftests/kvm/x86/xen_vmcall_test.c
new file mode 100644
index 000000000000..2585087cdf5c
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86/xen_vmcall_test.c
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * xen_vmcall_test
+ *
+ * Copyright © 2020 Amazon.com, Inc. or its affiliates.
+ *
+ * Userspace hypercall testing
+ */
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "processor.h"
+#include "hyperv.h"
+
+#define HCALL_REGION_GPA	0xc0000000ULL
+#define HCALL_REGION_SLOT	10
+
+#define INPUTVALUE 17
+#define ARGVALUE(x) (0xdeadbeef5a5a0000UL + x)
+#define RETVALUE 0xcafef00dfbfbffffUL
+
+#define XEN_HYPERCALL_MSR	0x40000200
+#define HV_GUEST_OS_ID_MSR	0x40000000
+#define HV_HYPERCALL_MSR	0x40000001
+
+#define HVCALL_SIGNAL_EVENT		0x005d
+#define HV_STATUS_INVALID_ALIGNMENT	4
+
+static void guest_code(void)
+{
+	unsigned long rax = INPUTVALUE;
+	unsigned long rdi = ARGVALUE(1);
+	unsigned long rsi = ARGVALUE(2);
+	unsigned long rdx = ARGVALUE(3);
+	unsigned long rcx;
+	register unsigned long r10 __asm__("r10") = ARGVALUE(4);
+	register unsigned long r8 __asm__("r8") = ARGVALUE(5);
+	register unsigned long r9 __asm__("r9") = ARGVALUE(6);
+
+	/* First a direct invocation of 'vmcall' */
+	__asm__ __volatile__("vmcall" :
+			     "=a"(rax) :
+			     "a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
+			     "r"(r10), "r"(r8), "r"(r9));
+	GUEST_ASSERT(rax == RETVALUE);
+
+	/* Fill in the Xen hypercall page */
+	__asm__ __volatile__("wrmsr" : : "c" (XEN_HYPERCALL_MSR),
+			     "a" (HCALL_REGION_GPA & 0xffffffff),
+			     "d" (HCALL_REGION_GPA >> 32));
+
+	/* Set Hyper-V Guest OS ID */
+	__asm__ __volatile__("wrmsr" : : "c" (HV_GUEST_OS_ID_MSR),
+			     "a" (0x5a), "d" (0));
+
+	/* Hyper-V hypercall page */
+	u64 msrval = HCALL_REGION_GPA + PAGE_SIZE + 1;
+	__asm__ __volatile__("wrmsr" : : "c" (HV_HYPERCALL_MSR),
+			     "a" (msrval & 0xffffffff),
+			     "d" (msrval >> 32));
+
+	/* Invoke a Xen hypercall */
+	__asm__ __volatile__("call *%1" : "=a"(rax) :
+			     "r"(HCALL_REGION_GPA + INPUTVALUE * 32),
+			     "a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
+			     "r"(r10), "r"(r8), "r"(r9));
+	GUEST_ASSERT(rax == RETVALUE);
+
+	/* Invoke a Hyper-V hypercall */
+	rax = 0;
+	rcx = HVCALL_SIGNAL_EVENT;	/* code */
+	rdx = 0x5a5a5a5a;		/* ingpa (badly aligned) */
+	__asm__ __volatile__("call *%1" : "=a"(rax) :
+			     "r"(HCALL_REGION_GPA + PAGE_SIZE),
+			     "a"(rax), "c"(rcx), "d"(rdx),
+			     "r"(r8));
+	GUEST_ASSERT(rax == HV_STATUS_INVALID_ALIGNMENT);
+
+	GUEST_DONE();
+}
+
+int main(int argc, char *argv[])
+{
+	unsigned int xen_caps;
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+
+	xen_caps = kvm_check_cap(KVM_CAP_XEN_HVM);
+	TEST_REQUIRE(xen_caps & KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL);
+
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+	vcpu_set_hv_cpuid(vcpu);
+
+	struct kvm_xen_hvm_config hvmc = {
+		.flags = KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL,
+		.msr = XEN_HYPERCALL_MSR,
+	};
+	vm_ioctl(vm, KVM_XEN_HVM_CONFIG, &hvmc);
+
+	/* Map a region for the hypercall pages */
+	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
+				    HCALL_REGION_GPA, HCALL_REGION_SLOT, 2, 0);
+	virt_map(vm, HCALL_REGION_GPA, HCALL_REGION_GPA, 2);
+
+	for (;;) {
+		volatile struct kvm_run *run = vcpu->run;
+		struct ucall uc;
+
+		vcpu_run(vcpu);
+
+		if (run->exit_reason == KVM_EXIT_XEN) {
+			TEST_ASSERT_EQ(run->xen.type, KVM_EXIT_XEN_HCALL);
+			TEST_ASSERT_EQ(run->xen.u.hcall.cpl, 0);
+			TEST_ASSERT_EQ(run->xen.u.hcall.longmode, 1);
+			TEST_ASSERT_EQ(run->xen.u.hcall.input, INPUTVALUE);
+			TEST_ASSERT_EQ(run->xen.u.hcall.params[0], ARGVALUE(1));
+			TEST_ASSERT_EQ(run->xen.u.hcall.params[1], ARGVALUE(2));
+			TEST_ASSERT_EQ(run->xen.u.hcall.params[2], ARGVALUE(3));
+			TEST_ASSERT_EQ(run->xen.u.hcall.params[3], ARGVALUE(4));
+			TEST_ASSERT_EQ(run->xen.u.hcall.params[4], ARGVALUE(5));
+			TEST_ASSERT_EQ(run->xen.u.hcall.params[5], ARGVALUE(6));
+			run->xen.u.hcall.result = RETVALUE;
+			continue;
+		}
+
+		TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
+
+		switch (get_ucall(vcpu, &uc)) {
+		case UCALL_ABORT:
+			REPORT_GUEST_ASSERT(uc);
+			/* NOT REACHED */
+		case UCALL_SYNC:
+			break;
+		case UCALL_DONE:
+			goto done;
+		default:
+			TEST_FAIL("Unknown ucall 0x%lx.", uc.cmd);
+		}
+	}
+done:
+	kvm_vm_free(vm);
+	return 0;
+}