1 /*
2 * COPYRIGHT (C) 2013-2014, Real-Thread Information Technology Ltd
3 * All rights reserved
4 *
5 * SPDX-License-Identifier: Apache-2.0
6 *
7 * Change Logs:
8 * Date Author Notes
9 * 2013-11-04 Grissiom add comment
10 */
11
12 #include <rthw.h>
13 #include <rtthread.h>
14 #include <interrupt.h>
15
16 #include <log_trace.h>
17 #include <vmm.h>
18
19 #include "vmm_context.h"
20
21 struct rt_vmm_share_layout rt_vmm_share SECTION(".vmm.share");
22
23 volatile struct vmm_context *_vmm_context = RT_NULL;
24
vmm_context_init(void * context_addr)25 void vmm_context_init(void *context_addr)
26 {
27 _vmm_context = (struct vmm_context *)context_addr;
28 rt_memset((void *)_vmm_context, 0x00, sizeof(struct vmm_context));
29 /* When loading RT-Thread, the IRQ on the guest should be disabled. */
30 _vmm_context->virq_status = 1;
31 }
32
33 #ifdef RT_VMM_USING_DOMAIN
34 unsigned long guest_domain_val SECTION(".bss.share");
35 unsigned long vmm_domain_val SECTION(".bss.share");
36 /* some RT-Thread code need to be called in the guest
37 * context(rt_thread_idle_excute for example). To simplify the code, we need a
38 * "super" domain mode to have access of both side. The code executed in super
39 * domain mode is restricted and should be harmless. */
40 unsigned long super_domain_val SECTION(".bss.share");
vmm_context_init_domain(struct vmm_domain * domain)41 void vmm_context_init_domain(struct vmm_domain *domain)
42 {
43 asm volatile ("mrc p15, 0, %0, c3, c0\n" : "=r" (guest_domain_val));
44
45 rt_kprintf("Linux domain: kernel: %d, user: %d, io: %d\n"
46 "VMM domain: vmm: %d, share: %d\n",
47 domain->kernel, domain->user, domain->io,
48 domain->vmm, domain->vmm_share);
49
50 if (domain->kernel == domain->vmm ||
51 domain->io == domain->vmm)
52 {
53 rt_kprintf("VMM and the guest share the same domain\n");
54 super_domain_val = vmm_domain_val = guest_domain_val;
55 return;
56 }
57
58 vmm_domain_val = guest_domain_val;
59
60 /* become client to our own territory */
61 vmm_domain_val |= (1 << (domain->vmm * 2)) | (1 << (domain->vmm_share * 2));
62
63 super_domain_val = vmm_domain_val;
64 /* super domain has access to both side */
65 super_domain_val |= (1 << (domain->kernel * 2)) | (1 << (domain->user * 2));
66
67 rt_kprintf("Original DAC: 0x%08x\n", guest_domain_val);
68 }
69
vmm_context_enter_domain(unsigned long domain_val)70 unsigned long vmm_context_enter_domain(unsigned long domain_val)
71 {
72 unsigned long old_domain;
73
74 asm volatile ("mrc p15, 0, %0, c3, c0\n" : "=r" (old_domain));
75 asm volatile ("mcr p15, 0, %0, c3, c0\n" : :"r" (domain_val) : "memory");
76
77 return old_domain;
78 }
79
vmm_context_restore_domain(unsigned long domain_val)80 void vmm_context_restore_domain(unsigned long domain_val)
81 {
82 asm volatile ("mcr p15, 0, %0, c3, c0\n" : :"r" (domain_val) : "memory");
83 }
84 #endif
85
vmm_virq_pending(int irq)86 void vmm_virq_pending(int irq)
87 {
88 /* when running this piece of code, the guest is already suspended. So it's
89 * safe to set the bits without locks. */
90 _vmm_context->virq_pending[irq / 32] |= (1 << (irq % 32));
91 _vmm_context->virq_pended = 1;
92 /* mask this IRQ in host */
93 rt_hw_interrupt_mask(irq);
94 }
95
vmm_virq_update(void)96 void vmm_virq_update(void)
97 {
98 if ((!_vmm_context->virq_status) &&
99 ( _vmm_context->virq_pended))
100 {
101 rt_hw_interrupt_trigger(RT_VMM_VIRQ_TRIGGER);
102 }
103 }
104
105 /** check the guest IRQ status
106 *
107 * @return 0 on guest should handle IRQ, -1 on should restore the guest context
108 * normally.
109 */
vmm_virq_check(void)110 int vmm_virq_check(void)
111 {
112 if ((!_vmm_context->virq_status) &&
113 ( _vmm_context->virq_pended))
114 {
115 return 0;
116 }
117
118 return -1;
119 }
120
121 /* 10 = len("%08x, ") */
122 static char _vmbuf[10*ARRAY_SIZE(_vmm_context->virq_pending)];
vmm_dump_virq(void)123 void vmm_dump_virq(void)
124 {
125 int i, s;
126
127 vmm_info("---- virtual IRQ ----\n");
128 vmm_info(" status: %08x, pended: %08x, pending:\n",
129 _vmm_context->virq_status, _vmm_context->virq_pended);
130 for (s = 0, i = 0; i < ARRAY_SIZE(_vmm_context->virq_pending); i++)
131 {
132 s += rt_snprintf(_vmbuf+s, sizeof(_vmbuf)-s,
133 "%08x, ", _vmm_context->virq_pending[i]);
134 }
135 vmm_info("%.*s\n", sizeof(_vmbuf), _vmbuf);
136 vmm_info("---- virtual IRQ ----\n");
137 }
138
vmm_virq_coherence_ok(void)139 int vmm_virq_coherence_ok(void)
140 {
141 int i, res;
142 int should_pend = 0;
143
144 for (i = 0; i < ARRAY_SIZE(_vmm_context->virq_pending); i++)
145 {
146 should_pend |= _vmm_context->virq_pending[i];
147 }
148
149 res = (_vmm_context->virq_pended == !!should_pend);
150
151 if (!res)
152 {
153 vmm_info("--- %x %x, %x\n",
154 _vmm_context->virq_pended, should_pend, !!should_pend);
155 }
156
157 return res;
158 }
159
160 extern struct rt_thread vmm_thread;
161
vmm_show_guest_reg(void)162 void vmm_show_guest_reg(void)
163 {
164 struct rt_hw_stack *sp = vmm_thread.sp;
165 #ifdef RT_VMM_USING_DOMAIN
166 unsigned long old_domain;
167
168 old_domain = vmm_context_enter_domain(super_domain_val);
169 #endif
170
171 vmm_info("CPSR: %08x, PC: %08x, LR: %08x, SP: %08x\n",
172 sp->cpsr, sp->pc, sp->lr, sp+1);
173
174 #ifdef RT_VMM_USING_DOMAIN
175 vmm_context_restore_domain(old_domain);
176 #endif
177 }
178
vmm_dump_domain(void)179 void vmm_dump_domain(void)
180 {
181 unsigned long dac;
182
183 asm volatile ("mrc p15, 0, %0, c3, c0\n" : "=r" (dac));
184 vmm_info("current DAC: %08x\n", dac);
185 #ifdef RT_VMM_USING_DOMAIN
186 vmm_info("guest DAC: %08x, RTT DAC: %08x, super DAC: %08x\n",
187 guest_domain_val, vmm_domain_val, super_domain_val);
188 #endif
189 }
190
vmm_show_guest(void)191 void vmm_show_guest(void)
192 {
193 vmm_show_guest_reg();
194 vmm_dump_virq();
195 vmm_dump_domain();
196 }
197
198 #ifdef RT_USING_FINSH
199 #include <finsh.h>
200 FINSH_FUNCTION_EXPORT_ALIAS(vmm_show_guest, vmm, show vmm status);
201 #endif
202
_bad_cpsr(unsigned long cpsr)203 static int _bad_cpsr(unsigned long cpsr)
204 {
205 int bad = 1;
206
207 switch (cpsr & MODEMASK)
208 {
209 case USERMODE:
210 case FIQMODE:
211 case IRQMODE:
212 case SVCMODE:
213 #ifdef CPU_HAS_MONITOR_MODE
214 case MONITORMODE:
215 #endif
216 case ABORTMODE:
217 #ifdef CPU_HAS_HYP_MODE
218 case HYPMODE:
219 #endif
220 case UNDEFMODE:
221 case MODEMASK:
222 bad = 0;
223 break;
224 };
225 return bad;
226 }
227
vmm_verify_guest_status(struct rt_hw_stack * sp)228 void vmm_verify_guest_status(struct rt_hw_stack *sp)
229 {
230 int dump_vmm = 0;
231 unsigned long cpsr;
232 #ifdef RT_VMM_USING_DOMAIN
233 unsigned long old_domain;
234
235 old_domain = vmm_context_enter_domain(super_domain_val);
236 #endif
237
238 cpsr = sp->cpsr;
239 if (_bad_cpsr(cpsr))
240 {
241 vmm_info("=================================\n");
242 vmm_info("VMM WARING: bad CPSR in guest\n");
243 dump_vmm = 1;
244 }
245 else
246 {
247 if (cpsr & A_Bit && 0)
248 {
249 vmm_info("=================================\n");
250 vmm_info("VMM WARING: A bit is set in guest\n");
251 dump_vmm = 1;
252 }
253 if ((cpsr & I_Bit) && (sp->pc <= VMM_BEGIN))
254 {
255 vmm_info("=================================\n");
256 vmm_info("VMM WARING: IRQ disabled in guest\n");
257 dump_vmm = 1;
258 }
259 if (cpsr & F_Bit)
260 {
261 vmm_info("=================================\n");
262 vmm_info("VMM WARING: FIQ disabled in guest\n");
263 dump_vmm = 1;
264 }
265 if ((cpsr & MODEMASK) == USERMODE)
266 {
267 if (_vmm_context->virq_status & 1)
268 {
269 vmm_info("=================================\n");
270 vmm_info("VMM WARING: VIRQ disabled in user mode\n");
271 dump_vmm = 1;
272 }
273 if ((sp->pc > 0xbf000000) && (sp->pc < 0xffff0000))
274 {
275 vmm_info("=================================\n");
276 vmm_info("VMM WARING: executing kernel code in usr mode\n");
277 dump_vmm = 1;
278 }
279 /* FIXME: when the guest is suspended in user mode and its
280 * interrupts come, this can be misleading. */
281 #if 0
282 if (_vmm_context->virq_pended)
283 {
284 vmm_info("=================================\n");
285 vmm_info("VMM WARING: VIRQ pended in user mode\n");
286 dump_vmm = 1;
287 }
288 #endif
289 }
290 else if ((cpsr & MODEMASK) == SVCMODE && sp->pc < 0xbf000000)
291 {
292 vmm_info("=================================\n");
293 vmm_info("VMM WARING: executing usr code in svc mode\n");
294 dump_vmm = 1;
295 }
296 }
297
298 #if 0
299 if (!vmm_virq_coherence_ok())
300 {
301 vmm_info("=================================\n");
302 vmm_info("VMM WARING: bad VIRQ status\n");
303 dump_vmm = 1;
304 }
305 #endif
306
307 if (dump_vmm)
308 {
309 vmm_show_guest();
310 vmm_info("=================================\n");
311 }
312
313 #ifdef RT_VMM_USING_DOMAIN
314 vmm_context_restore_domain(old_domain);
315 #endif
316 }
317
318