xref: /linux/arch/loongarch/kvm/main.c (revision 5e2cb28dd7e182dfa641550dfa225913509ad45d)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
4  */
5 
6 #include <linux/err.h>
7 #include <linux/module.h>
8 #include <linux/kvm_host.h>
9 #include <asm/cacheflush.h>
10 #include <asm/cpufeature.h>
11 #include <asm/kvm_csr.h>
12 #include "trace.h"
13 
14 unsigned long vpid_mask;
15 struct kvm_world_switch *kvm_loongarch_ops;
16 static int gcsr_flag[CSR_MAX_NUMS];
17 static struct kvm_context __percpu *vmcs;
18 
19 int get_gcsr_flag(int csr)
20 {
21 	if (csr < CSR_MAX_NUMS)
22 		return gcsr_flag[csr];
23 
24 	return INVALID_GCSR;
25 }
26 
27 static inline void set_gcsr_sw_flag(int csr)
28 {
29 	if (csr < CSR_MAX_NUMS)
30 		gcsr_flag[csr] |= SW_GCSR;
31 }
32 
33 static inline void set_gcsr_hw_flag(int csr)
34 {
35 	if (csr < CSR_MAX_NUMS)
36 		gcsr_flag[csr] |= HW_GCSR;
37 }
38 
39 /*
40  * The default value of gcsr_flag[CSR] is 0, and we use this
41  * function to set the flag to 1 (SW_GCSR) or 2 (HW_GCSR) if the
42  * gcsr is software or hardware. It will be used by get/set_gcsr,
43  * if gcsr_flag is HW we should use gcsrrd/gcsrwr to access it,
44  * else use software csr to emulate it.
45  */
46 static void kvm_init_gcsr_flag(void)
47 {
48 	set_gcsr_hw_flag(LOONGARCH_CSR_CRMD);
49 	set_gcsr_hw_flag(LOONGARCH_CSR_PRMD);
50 	set_gcsr_hw_flag(LOONGARCH_CSR_EUEN);
51 	set_gcsr_hw_flag(LOONGARCH_CSR_MISC);
52 	set_gcsr_hw_flag(LOONGARCH_CSR_ECFG);
53 	set_gcsr_hw_flag(LOONGARCH_CSR_ESTAT);
54 	set_gcsr_hw_flag(LOONGARCH_CSR_ERA);
55 	set_gcsr_hw_flag(LOONGARCH_CSR_BADV);
56 	set_gcsr_hw_flag(LOONGARCH_CSR_BADI);
57 	set_gcsr_hw_flag(LOONGARCH_CSR_EENTRY);
58 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBIDX);
59 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBEHI);
60 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBELO0);
61 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBELO1);
62 	set_gcsr_hw_flag(LOONGARCH_CSR_ASID);
63 	set_gcsr_hw_flag(LOONGARCH_CSR_PGDL);
64 	set_gcsr_hw_flag(LOONGARCH_CSR_PGDH);
65 	set_gcsr_hw_flag(LOONGARCH_CSR_PGD);
66 	set_gcsr_hw_flag(LOONGARCH_CSR_PWCTL0);
67 	set_gcsr_hw_flag(LOONGARCH_CSR_PWCTL1);
68 	set_gcsr_hw_flag(LOONGARCH_CSR_STLBPGSIZE);
69 	set_gcsr_hw_flag(LOONGARCH_CSR_RVACFG);
70 	set_gcsr_hw_flag(LOONGARCH_CSR_CPUID);
71 	set_gcsr_hw_flag(LOONGARCH_CSR_PRCFG1);
72 	set_gcsr_hw_flag(LOONGARCH_CSR_PRCFG2);
73 	set_gcsr_hw_flag(LOONGARCH_CSR_PRCFG3);
74 	set_gcsr_hw_flag(LOONGARCH_CSR_KS0);
75 	set_gcsr_hw_flag(LOONGARCH_CSR_KS1);
76 	set_gcsr_hw_flag(LOONGARCH_CSR_KS2);
77 	set_gcsr_hw_flag(LOONGARCH_CSR_KS3);
78 	set_gcsr_hw_flag(LOONGARCH_CSR_KS4);
79 	set_gcsr_hw_flag(LOONGARCH_CSR_KS5);
80 	set_gcsr_hw_flag(LOONGARCH_CSR_KS6);
81 	set_gcsr_hw_flag(LOONGARCH_CSR_KS7);
82 	set_gcsr_hw_flag(LOONGARCH_CSR_TMID);
83 	set_gcsr_hw_flag(LOONGARCH_CSR_TCFG);
84 	set_gcsr_hw_flag(LOONGARCH_CSR_TVAL);
85 	set_gcsr_hw_flag(LOONGARCH_CSR_TINTCLR);
86 	set_gcsr_hw_flag(LOONGARCH_CSR_CNTC);
87 	set_gcsr_hw_flag(LOONGARCH_CSR_LLBCTL);
88 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRENTRY);
89 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRBADV);
90 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRERA);
91 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRSAVE);
92 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRELO0);
93 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRELO1);
94 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBREHI);
95 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRPRMD);
96 	set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN0);
97 	set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN1);
98 	set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN2);
99 	set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN3);
100 
101 	set_gcsr_sw_flag(LOONGARCH_CSR_IMPCTL1);
102 	set_gcsr_sw_flag(LOONGARCH_CSR_IMPCTL2);
103 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRCTL);
104 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRINFO1);
105 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRINFO2);
106 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRENTRY);
107 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRERA);
108 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRSAVE);
109 	set_gcsr_sw_flag(LOONGARCH_CSR_CTAG);
110 	set_gcsr_sw_flag(LOONGARCH_CSR_DEBUG);
111 	set_gcsr_sw_flag(LOONGARCH_CSR_DERA);
112 	set_gcsr_sw_flag(LOONGARCH_CSR_DESAVE);
113 
114 	set_gcsr_sw_flag(LOONGARCH_CSR_FWPC);
115 	set_gcsr_sw_flag(LOONGARCH_CSR_FWPS);
116 	set_gcsr_sw_flag(LOONGARCH_CSR_MWPC);
117 	set_gcsr_sw_flag(LOONGARCH_CSR_MWPS);
118 
119 	set_gcsr_sw_flag(LOONGARCH_CSR_DB0ADDR);
120 	set_gcsr_sw_flag(LOONGARCH_CSR_DB0MASK);
121 	set_gcsr_sw_flag(LOONGARCH_CSR_DB0CTRL);
122 	set_gcsr_sw_flag(LOONGARCH_CSR_DB0ASID);
123 	set_gcsr_sw_flag(LOONGARCH_CSR_DB1ADDR);
124 	set_gcsr_sw_flag(LOONGARCH_CSR_DB1MASK);
125 	set_gcsr_sw_flag(LOONGARCH_CSR_DB1CTRL);
126 	set_gcsr_sw_flag(LOONGARCH_CSR_DB1ASID);
127 	set_gcsr_sw_flag(LOONGARCH_CSR_DB2ADDR);
128 	set_gcsr_sw_flag(LOONGARCH_CSR_DB2MASK);
129 	set_gcsr_sw_flag(LOONGARCH_CSR_DB2CTRL);
130 	set_gcsr_sw_flag(LOONGARCH_CSR_DB2ASID);
131 	set_gcsr_sw_flag(LOONGARCH_CSR_DB3ADDR);
132 	set_gcsr_sw_flag(LOONGARCH_CSR_DB3MASK);
133 	set_gcsr_sw_flag(LOONGARCH_CSR_DB3CTRL);
134 	set_gcsr_sw_flag(LOONGARCH_CSR_DB3ASID);
135 	set_gcsr_sw_flag(LOONGARCH_CSR_DB4ADDR);
136 	set_gcsr_sw_flag(LOONGARCH_CSR_DB4MASK);
137 	set_gcsr_sw_flag(LOONGARCH_CSR_DB4CTRL);
138 	set_gcsr_sw_flag(LOONGARCH_CSR_DB4ASID);
139 	set_gcsr_sw_flag(LOONGARCH_CSR_DB5ADDR);
140 	set_gcsr_sw_flag(LOONGARCH_CSR_DB5MASK);
141 	set_gcsr_sw_flag(LOONGARCH_CSR_DB5CTRL);
142 	set_gcsr_sw_flag(LOONGARCH_CSR_DB5ASID);
143 	set_gcsr_sw_flag(LOONGARCH_CSR_DB6ADDR);
144 	set_gcsr_sw_flag(LOONGARCH_CSR_DB6MASK);
145 	set_gcsr_sw_flag(LOONGARCH_CSR_DB6CTRL);
146 	set_gcsr_sw_flag(LOONGARCH_CSR_DB6ASID);
147 	set_gcsr_sw_flag(LOONGARCH_CSR_DB7ADDR);
148 	set_gcsr_sw_flag(LOONGARCH_CSR_DB7MASK);
149 	set_gcsr_sw_flag(LOONGARCH_CSR_DB7CTRL);
150 	set_gcsr_sw_flag(LOONGARCH_CSR_DB7ASID);
151 
152 	set_gcsr_sw_flag(LOONGARCH_CSR_IB0ADDR);
153 	set_gcsr_sw_flag(LOONGARCH_CSR_IB0MASK);
154 	set_gcsr_sw_flag(LOONGARCH_CSR_IB0CTRL);
155 	set_gcsr_sw_flag(LOONGARCH_CSR_IB0ASID);
156 	set_gcsr_sw_flag(LOONGARCH_CSR_IB1ADDR);
157 	set_gcsr_sw_flag(LOONGARCH_CSR_IB1MASK);
158 	set_gcsr_sw_flag(LOONGARCH_CSR_IB1CTRL);
159 	set_gcsr_sw_flag(LOONGARCH_CSR_IB1ASID);
160 	set_gcsr_sw_flag(LOONGARCH_CSR_IB2ADDR);
161 	set_gcsr_sw_flag(LOONGARCH_CSR_IB2MASK);
162 	set_gcsr_sw_flag(LOONGARCH_CSR_IB2CTRL);
163 	set_gcsr_sw_flag(LOONGARCH_CSR_IB2ASID);
164 	set_gcsr_sw_flag(LOONGARCH_CSR_IB3ADDR);
165 	set_gcsr_sw_flag(LOONGARCH_CSR_IB3MASK);
166 	set_gcsr_sw_flag(LOONGARCH_CSR_IB3CTRL);
167 	set_gcsr_sw_flag(LOONGARCH_CSR_IB3ASID);
168 	set_gcsr_sw_flag(LOONGARCH_CSR_IB4ADDR);
169 	set_gcsr_sw_flag(LOONGARCH_CSR_IB4MASK);
170 	set_gcsr_sw_flag(LOONGARCH_CSR_IB4CTRL);
171 	set_gcsr_sw_flag(LOONGARCH_CSR_IB4ASID);
172 	set_gcsr_sw_flag(LOONGARCH_CSR_IB5ADDR);
173 	set_gcsr_sw_flag(LOONGARCH_CSR_IB5MASK);
174 	set_gcsr_sw_flag(LOONGARCH_CSR_IB5CTRL);
175 	set_gcsr_sw_flag(LOONGARCH_CSR_IB5ASID);
176 	set_gcsr_sw_flag(LOONGARCH_CSR_IB6ADDR);
177 	set_gcsr_sw_flag(LOONGARCH_CSR_IB6MASK);
178 	set_gcsr_sw_flag(LOONGARCH_CSR_IB6CTRL);
179 	set_gcsr_sw_flag(LOONGARCH_CSR_IB6ASID);
180 	set_gcsr_sw_flag(LOONGARCH_CSR_IB7ADDR);
181 	set_gcsr_sw_flag(LOONGARCH_CSR_IB7MASK);
182 	set_gcsr_sw_flag(LOONGARCH_CSR_IB7CTRL);
183 	set_gcsr_sw_flag(LOONGARCH_CSR_IB7ASID);
184 
185 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL0);
186 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR0);
187 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL1);
188 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR1);
189 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL2);
190 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR2);
191 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL3);
192 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR3);
193 }
194 
195 static void kvm_update_vpid(struct kvm_vcpu *vcpu, int cpu)
196 {
197 	unsigned long vpid;
198 	struct kvm_context *context;
199 
200 	context = per_cpu_ptr(vcpu->kvm->arch.vmcs, cpu);
201 	vpid = context->vpid_cache + 1;
202 	if (!(vpid & vpid_mask)) {
203 		/* finish round of vpid loop */
204 		if (unlikely(!vpid))
205 			vpid = vpid_mask + 1;
206 
207 		++vpid; /* vpid 0 reserved for root */
208 
209 		/* start new vpid cycle */
210 		kvm_flush_tlb_all();
211 	}
212 
213 	context->vpid_cache = vpid;
214 	vcpu->arch.vpid = vpid;
215 }
216 
217 void kvm_check_vpid(struct kvm_vcpu *vcpu)
218 {
219 	int cpu;
220 	bool migrated;
221 	unsigned long ver, old, vpid;
222 	struct kvm_context *context;
223 
224 	cpu = smp_processor_id();
225 	/*
226 	 * Are we entering guest context on a different CPU to last time?
227 	 * If so, the vCPU's guest TLB state on this CPU may be stale.
228 	 */
229 	context = per_cpu_ptr(vcpu->kvm->arch.vmcs, cpu);
230 	migrated = (vcpu->cpu != cpu);
231 
232 	/*
233 	 * Check if our vpid is of an older version
234 	 *
235 	 * We also discard the stored vpid if we've executed on
236 	 * another CPU, as the guest mappings may have changed without
237 	 * hypervisor knowledge.
238 	 */
239 	ver = vcpu->arch.vpid & ~vpid_mask;
240 	old = context->vpid_cache  & ~vpid_mask;
241 	if (migrated || (ver != old)) {
242 		kvm_update_vpid(vcpu, cpu);
243 		trace_kvm_vpid_change(vcpu, vcpu->arch.vpid);
244 		vcpu->cpu = cpu;
245 	}
246 
247 	/* Restore GSTAT(0x50).vpid */
248 	vpid = (vcpu->arch.vpid & vpid_mask) << CSR_GSTAT_GID_SHIFT;
249 	change_csr_gstat(vpid_mask << CSR_GSTAT_GID_SHIFT, vpid);
250 }
251 
252 void kvm_init_vmcs(struct kvm *kvm)
253 {
254 	kvm->arch.vmcs = vmcs;
255 }
256 
257 long kvm_arch_dev_ioctl(struct file *filp,
258 			unsigned int ioctl, unsigned long arg)
259 {
260 	return -ENOIOCTLCMD;
261 }
262 
263 int kvm_arch_hardware_enable(void)
264 {
265 	unsigned long env, gcfg = 0;
266 
267 	env = read_csr_gcfg();
268 
269 	/* First init gcfg, gstat, gintc, gtlbc. All guest use the same config */
270 	write_csr_gcfg(0);
271 	write_csr_gstat(0);
272 	write_csr_gintc(0);
273 	clear_csr_gtlbc(CSR_GTLBC_USETGID | CSR_GTLBC_TOTI);
274 
275 	/*
276 	 * Enable virtualization features granting guest direct control of
277 	 * certain features:
278 	 * GCI=2:       Trap on init or unimplement cache instruction.
279 	 * TORU=0:      Trap on Root Unimplement.
280 	 * CACTRL=1:    Root control cache.
281 	 * TOP=0:       Trap on Previlege.
282 	 * TOE=0:       Trap on Exception.
283 	 * TIT=0:       Trap on Timer.
284 	 */
285 	if (env & CSR_GCFG_GCIP_ALL)
286 		gcfg |= CSR_GCFG_GCI_SECURE;
287 	if (env & CSR_GCFG_MATC_ROOT)
288 		gcfg |= CSR_GCFG_MATC_ROOT;
289 
290 	gcfg |= CSR_GCFG_TIT;
291 	write_csr_gcfg(gcfg);
292 
293 	kvm_flush_tlb_all();
294 
295 	/* Enable using TGID  */
296 	set_csr_gtlbc(CSR_GTLBC_USETGID);
297 	kvm_debug("GCFG:%lx GSTAT:%lx GINTC:%lx GTLBC:%lx",
298 		  read_csr_gcfg(), read_csr_gstat(), read_csr_gintc(), read_csr_gtlbc());
299 
300 	return 0;
301 }
302 
303 void kvm_arch_hardware_disable(void)
304 {
305 	write_csr_gcfg(0);
306 	write_csr_gstat(0);
307 	write_csr_gintc(0);
308 	clear_csr_gtlbc(CSR_GTLBC_USETGID | CSR_GTLBC_TOTI);
309 
310 	/* Flush any remaining guest TLB entries */
311 	kvm_flush_tlb_all();
312 }
313 
314 static int kvm_loongarch_env_init(void)
315 {
316 	int cpu, order;
317 	void *addr;
318 	struct kvm_context *context;
319 
320 	vmcs = alloc_percpu(struct kvm_context);
321 	if (!vmcs) {
322 		pr_err("kvm: failed to allocate percpu kvm_context\n");
323 		return -ENOMEM;
324 	}
325 
326 	kvm_loongarch_ops = kzalloc(sizeof(*kvm_loongarch_ops), GFP_KERNEL);
327 	if (!kvm_loongarch_ops) {
328 		free_percpu(vmcs);
329 		vmcs = NULL;
330 		return -ENOMEM;
331 	}
332 
333 	/*
334 	 * PGD register is shared between root kernel and kvm hypervisor.
335 	 * So world switch entry should be in DMW area rather than TLB area
336 	 * to avoid page fault reenter.
337 	 *
338 	 * In future if hardware pagetable walking is supported, we won't
339 	 * need to copy world switch code to DMW area.
340 	 */
341 	order = get_order(kvm_exception_size + kvm_enter_guest_size);
342 	addr = (void *)__get_free_pages(GFP_KERNEL, order);
343 	if (!addr) {
344 		free_percpu(vmcs);
345 		vmcs = NULL;
346 		kfree(kvm_loongarch_ops);
347 		kvm_loongarch_ops = NULL;
348 		return -ENOMEM;
349 	}
350 
351 	memcpy(addr, kvm_exc_entry, kvm_exception_size);
352 	memcpy(addr + kvm_exception_size, kvm_enter_guest, kvm_enter_guest_size);
353 	flush_icache_range((unsigned long)addr, (unsigned long)addr + kvm_exception_size + kvm_enter_guest_size);
354 	kvm_loongarch_ops->exc_entry = addr;
355 	kvm_loongarch_ops->enter_guest = addr + kvm_exception_size;
356 	kvm_loongarch_ops->page_order = order;
357 
358 	vpid_mask = read_csr_gstat();
359 	vpid_mask = (vpid_mask & CSR_GSTAT_GIDBIT) >> CSR_GSTAT_GIDBIT_SHIFT;
360 	if (vpid_mask)
361 		vpid_mask = GENMASK(vpid_mask - 1, 0);
362 
363 	for_each_possible_cpu(cpu) {
364 		context = per_cpu_ptr(vmcs, cpu);
365 		context->vpid_cache = vpid_mask + 1;
366 		context->last_vcpu = NULL;
367 	}
368 
369 	kvm_init_gcsr_flag();
370 
371 	return 0;
372 }
373 
374 static void kvm_loongarch_env_exit(void)
375 {
376 	unsigned long addr;
377 
378 	if (vmcs)
379 		free_percpu(vmcs);
380 
381 	if (kvm_loongarch_ops) {
382 		if (kvm_loongarch_ops->exc_entry) {
383 			addr = (unsigned long)kvm_loongarch_ops->exc_entry;
384 			free_pages(addr, kvm_loongarch_ops->page_order);
385 		}
386 		kfree(kvm_loongarch_ops);
387 	}
388 }
389 
390 static int kvm_loongarch_init(void)
391 {
392 	int r;
393 
394 	if (!cpu_has_lvz) {
395 		kvm_info("Hardware virtualization not available\n");
396 		return -ENODEV;
397 	}
398 	r = kvm_loongarch_env_init();
399 	if (r)
400 		return r;
401 
402 	return kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
403 }
404 
405 static void kvm_loongarch_exit(void)
406 {
407 	kvm_exit();
408 	kvm_loongarch_env_exit();
409 }
410 
411 module_init(kvm_loongarch_init);
412 module_exit(kvm_loongarch_exit);
413 
414 #ifdef MODULE
415 static const struct cpu_feature kvm_feature[] = {
416 	{ .feature = cpu_feature(LOONGARCH_LVZ) },
417 	{},
418 };
419 MODULE_DEVICE_TABLE(cpu, kvm_feature);
420 #endif
421