xen_vmcall_test.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * xen_vmcall_test
  4 *
  5 * Copyright © 2020 Amazon.com, Inc. or its affiliates.
  6 *
  7 * Userspace hypercall testing
  8 */
  9
 10#include "test_util.h"
 11#include "kvm_util.h"
 12#include "processor.h"
 13#include "hyperv.h"
 14
 15#define HCALL_REGION_GPA	0xc0000000ULL
 16#define HCALL_REGION_SLOT	10
 17
 18#define INPUTVALUE 17
 19#define ARGVALUE(x) (0xdeadbeef5a5a0000UL + x)
 20#define RETVALUE 0xcafef00dfbfbffffUL
 21
 22#define XEN_HYPERCALL_MSR	0x40000200
 23#define HV_GUEST_OS_ID_MSR	0x40000000
 24#define HV_HYPERCALL_MSR	0x40000001
 25
 26#define HVCALL_SIGNAL_EVENT		0x005d
 27#define HV_STATUS_INVALID_ALIGNMENT	4
 28
 29static void guest_code(void)
 30{
 31	unsigned long rax = INPUTVALUE;
 32	unsigned long rdi = ARGVALUE(1);
 33	unsigned long rsi = ARGVALUE(2);
 34	unsigned long rdx = ARGVALUE(3);
 35	unsigned long rcx;
 36	register unsigned long r10 __asm__("r10") = ARGVALUE(4);
 37	register unsigned long r8 __asm__("r8") = ARGVALUE(5);
 38	register unsigned long r9 __asm__("r9") = ARGVALUE(6);
 39
 40	/* First a direct invocation of 'vmcall' */
 41	__asm__ __volatile__("vmcall" :
 42			     "=a"(rax) :
 43			     "a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
 44			     "r"(r10), "r"(r8), "r"(r9));
 45	GUEST_ASSERT(rax == RETVALUE);
 46
 47	/* Fill in the Xen hypercall page */
 48	__asm__ __volatile__("wrmsr" : : "c" (XEN_HYPERCALL_MSR),
 49			     "a" (HCALL_REGION_GPA & 0xffffffff),
 50			     "d" (HCALL_REGION_GPA >> 32));
 51
 52	/* Set Hyper-V Guest OS ID */
 53	__asm__ __volatile__("wrmsr" : : "c" (HV_GUEST_OS_ID_MSR),
 54			     "a" (0x5a), "d" (0));
 55
 56	/* Hyper-V hypercall page */
 57	u64 msrval = HCALL_REGION_GPA + PAGE_SIZE + 1;
 58	__asm__ __volatile__("wrmsr" : : "c" (HV_HYPERCALL_MSR),
 59			     "a" (msrval & 0xffffffff),
 60			     "d" (msrval >> 32));
 61
 62	/* Invoke a Xen hypercall */
 63	__asm__ __volatile__("call *%1" : "=a"(rax) :
 64			     "r"(HCALL_REGION_GPA + INPUTVALUE * 32),
 65			     "a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
 66			     "r"(r10), "r"(r8), "r"(r9));
 67	GUEST_ASSERT(rax == RETVALUE);
 68
 69	/* Invoke a Hyper-V hypercall */
 70	rax = 0;
 71	rcx = HVCALL_SIGNAL_EVENT;	/* code */
 72	rdx = 0x5a5a5a5a;		/* ingpa (badly aligned) */
 73	__asm__ __volatile__("call *%1" : "=a"(rax) :
 74			     "r"(HCALL_REGION_GPA + PAGE_SIZE),
 75			     "a"(rax), "c"(rcx), "d"(rdx),
 76			     "r"(r8));
 77	GUEST_ASSERT(rax == HV_STATUS_INVALID_ALIGNMENT);
 78
 79	GUEST_DONE();
 80}
 81
 82int main(int argc, char *argv[])
 83{
 84	unsigned int xen_caps;
 85	struct kvm_vcpu *vcpu;
 86	struct kvm_vm *vm;
 87
 88	xen_caps = kvm_check_cap(KVM_CAP_XEN_HVM);
 89	TEST_REQUIRE(xen_caps & KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL);
 90
 91	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
 92	vcpu_set_hv_cpuid(vcpu);
 93
 94	struct kvm_xen_hvm_config hvmc = {
 95		.flags = KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL,
 96		.msr = XEN_HYPERCALL_MSR,
 97	};
 98	vm_ioctl(vm, KVM_XEN_HVM_CONFIG, &hvmc);
 99
100	/* Map a region for the hypercall pages */
101	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
102				    HCALL_REGION_GPA, HCALL_REGION_SLOT, 2, 0);
103	virt_map(vm, HCALL_REGION_GPA, HCALL_REGION_GPA, 2);
104
105	for (;;) {
106		volatile struct kvm_run *run = vcpu->run;
107		struct ucall uc;
108
109		vcpu_run(vcpu);
110
111		if (run->exit_reason == KVM_EXIT_XEN) {
112			TEST_ASSERT_EQ(run->xen.type, KVM_EXIT_XEN_HCALL);
113			TEST_ASSERT_EQ(run->xen.u.hcall.cpl, 0);
114			TEST_ASSERT_EQ(run->xen.u.hcall.longmode, 1);
115			TEST_ASSERT_EQ(run->xen.u.hcall.input, INPUTVALUE);
116			TEST_ASSERT_EQ(run->xen.u.hcall.params[0], ARGVALUE(1));
117			TEST_ASSERT_EQ(run->xen.u.hcall.params[1], ARGVALUE(2));
118			TEST_ASSERT_EQ(run->xen.u.hcall.params[2], ARGVALUE(3));
119			TEST_ASSERT_EQ(run->xen.u.hcall.params[3], ARGVALUE(4));
120			TEST_ASSERT_EQ(run->xen.u.hcall.params[4], ARGVALUE(5));
121			TEST_ASSERT_EQ(run->xen.u.hcall.params[5], ARGVALUE(6));
122			run->xen.u.hcall.result = RETVALUE;
123			continue;
124		}
125
126		TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
127
128		switch (get_ucall(vcpu, &uc)) {
129		case UCALL_ABORT:
130			REPORT_GUEST_ASSERT(uc);
131			/* NOT REACHED */
132		case UCALL_SYNC:
133			break;
134		case UCALL_DONE:
135			goto done;
136		default:
137			TEST_FAIL("Unknown ucall 0x%lx.", uc.cmd);
138		}
139	}
140done:
141	kvm_vm_free(vm);
142	return 0;
143}