1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2018, Red Hat, Inc.
4  *
5  * Tests for SMM.
6  */
7 #define _GNU_SOURCE /* for program_invocation_short_name */
8 #include <fcntl.h>
9 #include <stdio.h>
10 #include <stdlib.h>
11 #include <stdint.h>
12 #include <string.h>
13 #include <sys/ioctl.h>
14 
15 #include "test_util.h"
16 
17 #include "kvm_util.h"
18 
19 #include "vmx.h"
20 #include "svm_util.h"
21 
22 #define VCPU_ID	      1
23 
24 #define PAGE_SIZE  4096
25 
26 #define SMRAM_SIZE 65536
27 #define SMRAM_MEMSLOT ((1 << 16) | 1)
28 #define SMRAM_PAGES (SMRAM_SIZE / PAGE_SIZE)
29 #define SMRAM_GPA 0x1000000
30 #define SMRAM_STAGE 0xfe
31 
32 #define STR(x) #x
33 #define XSTR(s) STR(s)
34 
35 #define SYNC_PORT 0xe
36 #define DONE 0xff
37 
38 /*
39  * This is compiled as normal 64-bit code, however, SMI handler is executed
40  * in real-address mode. To stay simple we're limiting ourselves to a mode
41  * independent subset of asm here.
42  * SMI handler always report back fixed stage SMRAM_STAGE.
43  */
44 uint8_t smi_handler[] = {
45 	0xb0, SMRAM_STAGE,    /* mov $SMRAM_STAGE, %al */
46 	0xe4, SYNC_PORT,      /* in $SYNC_PORT, %al */
47 	0x0f, 0xaa,           /* rsm */
48 };
49 
50 static inline void sync_with_host(uint64_t phase)
51 {
52 	asm volatile("in $" XSTR(SYNC_PORT)", %%al \n"
53 		     : "+a" (phase));
54 }
55 
56 void self_smi(void)
57 {
58 	wrmsr(APIC_BASE_MSR + (APIC_ICR >> 4),
59 	      APIC_DEST_SELF | APIC_INT_ASSERT | APIC_DM_SMI);
60 }
61 
62 void guest_code(void *arg)
63 {
64 	uint64_t apicbase = rdmsr(MSR_IA32_APICBASE);
65 
66 	sync_with_host(1);
67 
68 	wrmsr(MSR_IA32_APICBASE, apicbase | X2APIC_ENABLE);
69 
70 	sync_with_host(2);
71 
72 	self_smi();
73 
74 	sync_with_host(4);
75 
76 	if (arg) {
77 		if (cpu_has_svm())
78 			generic_svm_setup(arg, NULL, NULL);
79 		else
80 			GUEST_ASSERT(prepare_for_vmx_operation(arg));
81 
82 		sync_with_host(5);
83 
84 		self_smi();
85 
86 		sync_with_host(7);
87 	}
88 
89 	sync_with_host(DONE);
90 }
91 
92 int main(int argc, char *argv[])
93 {
94 	vm_vaddr_t nested_gva = 0;
95 
96 	struct kvm_regs regs;
97 	struct kvm_vm *vm;
98 	struct kvm_run *run;
99 	struct kvm_x86_state *state;
100 	int stage, stage_reported;
101 
102 	/* Create VM */
103 	vm = vm_create_default(VCPU_ID, 0, guest_code);
104 
105 	vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
106 
107 	run = vcpu_state(vm, VCPU_ID);
108 
109 	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, SMRAM_GPA,
110 				    SMRAM_MEMSLOT, SMRAM_PAGES, 0);
111 	TEST_ASSERT(vm_phy_pages_alloc(vm, SMRAM_PAGES, SMRAM_GPA, SMRAM_MEMSLOT)
112 		    == SMRAM_GPA, "could not allocate guest physical addresses?");
113 
114 	memset(addr_gpa2hva(vm, SMRAM_GPA), 0x0, SMRAM_SIZE);
115 	memcpy(addr_gpa2hva(vm, SMRAM_GPA) + 0x8000, smi_handler,
116 	       sizeof(smi_handler));
117 
118 	vcpu_set_msr(vm, VCPU_ID, MSR_IA32_SMBASE, SMRAM_GPA);
119 
120 	if (kvm_check_cap(KVM_CAP_NESTED_STATE)) {
121 		if (nested_svm_supported())
122 			vcpu_alloc_svm(vm, &nested_gva);
123 		else if (nested_vmx_supported())
124 			vcpu_alloc_vmx(vm, &nested_gva);
125 	}
126 
127 	if (!nested_gva)
128 		pr_info("will skip SMM test with VMX enabled\n");
129 
130 	vcpu_args_set(vm, VCPU_ID, 1, nested_gva);
131 
132 	for (stage = 1;; stage++) {
133 		_vcpu_run(vm, VCPU_ID);
134 		TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
135 			    "Stage %d: unexpected exit reason: %u (%s),\n",
136 			    stage, run->exit_reason,
137 			    exit_reason_str(run->exit_reason));
138 
139 		memset(&regs, 0, sizeof(regs));
140 		vcpu_regs_get(vm, VCPU_ID, &regs);
141 
142 		stage_reported = regs.rax & 0xff;
143 
144 		if (stage_reported == DONE)
145 			goto done;
146 
147 		TEST_ASSERT(stage_reported == stage ||
148 			    stage_reported == SMRAM_STAGE,
149 			    "Unexpected stage: #%x, got %x",
150 			    stage, stage_reported);
151 
152 		state = vcpu_save_state(vm, VCPU_ID);
153 		kvm_vm_release(vm);
154 		kvm_vm_restart(vm, O_RDWR);
155 		vm_vcpu_add(vm, VCPU_ID);
156 		vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
157 		vcpu_load_state(vm, VCPU_ID, state);
158 		run = vcpu_state(vm, VCPU_ID);
159 		free(state);
160 	}
161 
162 done:
163 	kvm_vm_free(vm);
164 }
165