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 static void self_smi(void)
57 {
58 	x2apic_write_reg(APIC_ICR,
59 			 APIC_DEST_SELF | APIC_INT_ASSERT | APIC_DM_SMI);
60 }
61 
62 static void l2_guest_code(void)
63 {
64 	sync_with_host(8);
65 
66 	sync_with_host(10);
67 
68 	vmcall();
69 }
70 
71 static void guest_code(void *arg)
72 {
73 	#define L2_GUEST_STACK_SIZE 64
74 	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
75 	uint64_t apicbase = rdmsr(MSR_IA32_APICBASE);
76 	struct svm_test_data *svm = arg;
77 	struct vmx_pages *vmx_pages = arg;
78 
79 	sync_with_host(1);
80 
81 	wrmsr(MSR_IA32_APICBASE, apicbase | X2APIC_ENABLE);
82 
83 	sync_with_host(2);
84 
85 	self_smi();
86 
87 	sync_with_host(4);
88 
89 	if (arg) {
90 		if (cpu_has_svm()) {
91 			generic_svm_setup(svm, l2_guest_code,
92 					  &l2_guest_stack[L2_GUEST_STACK_SIZE]);
93 		} else {
94 			GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
95 			GUEST_ASSERT(load_vmcs(vmx_pages));
96 			prepare_vmcs(vmx_pages, l2_guest_code,
97 				     &l2_guest_stack[L2_GUEST_STACK_SIZE]);
98 		}
99 
100 		sync_with_host(5);
101 
102 		self_smi();
103 
104 		sync_with_host(7);
105 
106 		if (cpu_has_svm()) {
107 			run_guest(svm->vmcb, svm->vmcb_gpa);
108 			run_guest(svm->vmcb, svm->vmcb_gpa);
109 		} else {
110 			vmlaunch();
111 			vmresume();
112 		}
113 
114 		/* Stages 8-11 are eaten by SMM (SMRAM_STAGE reported instead) */
115 		sync_with_host(12);
116 	}
117 
118 	sync_with_host(DONE);
119 }
120 
121 void inject_smi(struct kvm_vm *vm)
122 {
123 	struct kvm_vcpu_events events;
124 
125 	vcpu_events_get(vm, VCPU_ID, &events);
126 
127 	events.smi.pending = 1;
128 	events.flags |= KVM_VCPUEVENT_VALID_SMM;
129 
130 	vcpu_events_set(vm, VCPU_ID, &events);
131 }
132 
133 int main(int argc, char *argv[])
134 {
135 	vm_vaddr_t nested_gva = 0;
136 
137 	struct kvm_regs regs;
138 	struct kvm_vm *vm;
139 	struct kvm_run *run;
140 	struct kvm_x86_state *state;
141 	int stage, stage_reported;
142 
143 	/* Create VM */
144 	vm = vm_create_default(VCPU_ID, 0, guest_code);
145 
146 	run = vcpu_state(vm, VCPU_ID);
147 
148 	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, SMRAM_GPA,
149 				    SMRAM_MEMSLOT, SMRAM_PAGES, 0);
150 	TEST_ASSERT(vm_phy_pages_alloc(vm, SMRAM_PAGES, SMRAM_GPA, SMRAM_MEMSLOT)
151 		    == SMRAM_GPA, "could not allocate guest physical addresses?");
152 
153 	memset(addr_gpa2hva(vm, SMRAM_GPA), 0x0, SMRAM_SIZE);
154 	memcpy(addr_gpa2hva(vm, SMRAM_GPA) + 0x8000, smi_handler,
155 	       sizeof(smi_handler));
156 
157 	vcpu_set_msr(vm, VCPU_ID, MSR_IA32_SMBASE, SMRAM_GPA);
158 
159 	if (kvm_check_cap(KVM_CAP_NESTED_STATE)) {
160 		if (nested_svm_supported())
161 			vcpu_alloc_svm(vm, &nested_gva);
162 		else if (nested_vmx_supported())
163 			vcpu_alloc_vmx(vm, &nested_gva);
164 	}
165 
166 	if (!nested_gva)
167 		pr_info("will skip SMM test with VMX enabled\n");
168 
169 	vcpu_args_set(vm, VCPU_ID, 1, nested_gva);
170 
171 	for (stage = 1;; stage++) {
172 		_vcpu_run(vm, VCPU_ID);
173 		TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
174 			    "Stage %d: unexpected exit reason: %u (%s),\n",
175 			    stage, run->exit_reason,
176 			    exit_reason_str(run->exit_reason));
177 
178 		memset(&regs, 0, sizeof(regs));
179 		vcpu_regs_get(vm, VCPU_ID, &regs);
180 
181 		stage_reported = regs.rax & 0xff;
182 
183 		if (stage_reported == DONE)
184 			goto done;
185 
186 		TEST_ASSERT(stage_reported == stage ||
187 			    stage_reported == SMRAM_STAGE,
188 			    "Unexpected stage: #%x, got %x",
189 			    stage, stage_reported);
190 
191 		/*
192 		 * Enter SMM during L2 execution and check that we correctly
193 		 * return from it. Do not perform save/restore while in SMM yet.
194 		 */
195 		if (stage == 8) {
196 			inject_smi(vm);
197 			continue;
198 		}
199 
200 		/*
201 		 * Perform save/restore while the guest is in SMM triggered
202 		 * during L2 execution.
203 		 */
204 		if (stage == 10)
205 			inject_smi(vm);
206 
207 		state = vcpu_save_state(vm, VCPU_ID);
208 		kvm_vm_release(vm);
209 		kvm_vm_restart(vm, O_RDWR);
210 		vm_vcpu_add(vm, VCPU_ID);
211 		vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
212 		vcpu_load_state(vm, VCPU_ID, state);
213 		run = vcpu_state(vm, VCPU_ID);
214 		kvm_x86_state_cleanup(state);
215 	}
216 
217 done:
218 	kvm_vm_free(vm);
219 }
220