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 VCPU_ID 5
15
16 #define HCALL_REGION_GPA 0xc0000000ULL
17 #define HCALL_REGION_SLOT 10
18 #define PAGE_SIZE 4096
19
20 static struct kvm_vm *vm;
21
22 #define INPUTVALUE 17
23 #define ARGVALUE(x) (0xdeadbeef5a5a0000UL + x)
24 #define RETVALUE 0xcafef00dfbfbffffUL
25
26 #define XEN_HYPERCALL_MSR 0x40000200
27 #define HV_GUEST_OS_ID_MSR 0x40000000
28 #define HV_HYPERCALL_MSR 0x40000001
29
30 #define HVCALL_SIGNAL_EVENT 0x005d
31 #define HV_STATUS_INVALID_ALIGNMENT 4
32
guest_code(void)33 static void guest_code(void)
34 {
35 unsigned long rax = INPUTVALUE;
36 unsigned long rdi = ARGVALUE(1);
37 unsigned long rsi = ARGVALUE(2);
38 unsigned long rdx = ARGVALUE(3);
39 unsigned long rcx;
40 register unsigned long r10 __asm__("r10") = ARGVALUE(4);
41 register unsigned long r8 __asm__("r8") = ARGVALUE(5);
42 register unsigned long r9 __asm__("r9") = ARGVALUE(6);
43
44 /* First a direct invocation of 'vmcall' */
45 __asm__ __volatile__("vmcall" :
46 "=a"(rax) :
47 "a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
48 "r"(r10), "r"(r8), "r"(r9));
49 GUEST_ASSERT(rax == RETVALUE);
50
51 /* Fill in the Xen hypercall page */
52 __asm__ __volatile__("wrmsr" : : "c" (XEN_HYPERCALL_MSR),
53 "a" (HCALL_REGION_GPA & 0xffffffff),
54 "d" (HCALL_REGION_GPA >> 32));
55
56 /* Set Hyper-V Guest OS ID */
57 __asm__ __volatile__("wrmsr" : : "c" (HV_GUEST_OS_ID_MSR),
58 "a" (0x5a), "d" (0));
59
60 /* Hyper-V hypercall page */
61 u64 msrval = HCALL_REGION_GPA + PAGE_SIZE + 1;
62 __asm__ __volatile__("wrmsr" : : "c" (HV_HYPERCALL_MSR),
63 "a" (msrval & 0xffffffff),
64 "d" (msrval >> 32));
65
66 /* Invoke a Xen hypercall */
67 __asm__ __volatile__("call *%1" : "=a"(rax) :
68 "r"(HCALL_REGION_GPA + INPUTVALUE * 32),
69 "a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
70 "r"(r10), "r"(r8), "r"(r9));
71 GUEST_ASSERT(rax == RETVALUE);
72
73 /* Invoke a Hyper-V hypercall */
74 rax = 0;
75 rcx = HVCALL_SIGNAL_EVENT; /* code */
76 rdx = 0x5a5a5a5a; /* ingpa (badly aligned) */
77 __asm__ __volatile__("call *%1" : "=a"(rax) :
78 "r"(HCALL_REGION_GPA + PAGE_SIZE),
79 "a"(rax), "c"(rcx), "d"(rdx),
80 "r"(r8));
81 GUEST_ASSERT(rax == HV_STATUS_INVALID_ALIGNMENT);
82
83 GUEST_DONE();
84 }
85
main(int argc,char * argv[])86 int main(int argc, char *argv[])
87 {
88 if (!(kvm_check_cap(KVM_CAP_XEN_HVM) &
89 KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL) ) {
90 print_skip("KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL not available");
91 exit(KSFT_SKIP);
92 }
93
94 vm = vm_create_default(VCPU_ID, 0, (void *) guest_code);
95 vcpu_set_hv_cpuid(vm, VCPU_ID);
96
97 struct kvm_xen_hvm_config hvmc = {
98 .flags = KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL,
99 .msr = XEN_HYPERCALL_MSR,
100 };
101 vm_ioctl(vm, KVM_XEN_HVM_CONFIG, &hvmc);
102
103 /* Map a region for the hypercall pages */
104 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
105 HCALL_REGION_GPA, HCALL_REGION_SLOT, 2, 0);
106 virt_map(vm, HCALL_REGION_GPA, HCALL_REGION_GPA, 2);
107
108 for (;;) {
109 volatile struct kvm_run *run = vcpu_state(vm, VCPU_ID);
110 struct ucall uc;
111
112 vcpu_run(vm, VCPU_ID);
113
114 if (run->exit_reason == KVM_EXIT_XEN) {
115 ASSERT_EQ(run->xen.type, KVM_EXIT_XEN_HCALL);
116 ASSERT_EQ(run->xen.u.hcall.cpl, 0);
117 ASSERT_EQ(run->xen.u.hcall.longmode, 1);
118 ASSERT_EQ(run->xen.u.hcall.input, INPUTVALUE);
119 ASSERT_EQ(run->xen.u.hcall.params[0], ARGVALUE(1));
120 ASSERT_EQ(run->xen.u.hcall.params[1], ARGVALUE(2));
121 ASSERT_EQ(run->xen.u.hcall.params[2], ARGVALUE(3));
122 ASSERT_EQ(run->xen.u.hcall.params[3], ARGVALUE(4));
123 ASSERT_EQ(run->xen.u.hcall.params[4], ARGVALUE(5));
124 ASSERT_EQ(run->xen.u.hcall.params[5], ARGVALUE(6));
125 run->xen.u.hcall.result = RETVALUE;
126 continue;
127 }
128
129 TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
130 "Got exit_reason other than KVM_EXIT_IO: %u (%s)\n",
131 run->exit_reason,
132 exit_reason_str(run->exit_reason));
133
134 switch (get_ucall(vm, VCPU_ID, &uc)) {
135 case UCALL_ABORT:
136 TEST_FAIL("%s", (const char *)uc.args[0]);
137 /* NOT REACHED */
138 case UCALL_SYNC:
139 break;
140 case UCALL_DONE:
141 goto done;
142 default:
143 TEST_FAIL("Unknown ucall 0x%lx.", uc.cmd);
144 }
145 }
146 done:
147 kvm_vm_free(vm);
148 return 0;
149 }
150