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