xref: /linux/arch/loongarch/kvm/main.c (revision 2e8b9df82631e714cc2b7bf302772c8259673180)
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 <asm/kvm_eiointc.h>
13 #include "trace.h"
14 
15 unsigned long vpid_mask;
16 struct kvm_world_switch *kvm_loongarch_ops;
17 static int gcsr_flag[CSR_MAX_NUMS];
18 static struct kvm_context __percpu *vmcs;
19 
20 int get_gcsr_flag(int csr)
21 {
22 	if (csr < CSR_MAX_NUMS)
23 		return gcsr_flag[csr];
24 
25 	return INVALID_GCSR;
26 }
27 
28 static inline void set_gcsr_sw_flag(int csr)
29 {
30 	if (csr < CSR_MAX_NUMS)
31 		gcsr_flag[csr] |= SW_GCSR;
32 }
33 
34 static inline void set_gcsr_hw_flag(int csr)
35 {
36 	if (csr < CSR_MAX_NUMS)
37 		gcsr_flag[csr] |= HW_GCSR;
38 }
39 
40 /*
41  * The default value of gcsr_flag[CSR] is 0, and we use this
42  * function to set the flag to 1 (SW_GCSR) or 2 (HW_GCSR) if the
43  * gcsr is software or hardware. It will be used by get/set_gcsr,
44  * if gcsr_flag is HW we should use gcsrrd/gcsrwr to access it,
45  * else use software csr to emulate it.
46  */
47 static void kvm_init_gcsr_flag(void)
48 {
49 	set_gcsr_hw_flag(LOONGARCH_CSR_CRMD);
50 	set_gcsr_hw_flag(LOONGARCH_CSR_PRMD);
51 	set_gcsr_hw_flag(LOONGARCH_CSR_EUEN);
52 	set_gcsr_hw_flag(LOONGARCH_CSR_MISC);
53 	set_gcsr_hw_flag(LOONGARCH_CSR_ECFG);
54 	set_gcsr_hw_flag(LOONGARCH_CSR_ESTAT);
55 	set_gcsr_hw_flag(LOONGARCH_CSR_ERA);
56 	set_gcsr_hw_flag(LOONGARCH_CSR_BADV);
57 	set_gcsr_hw_flag(LOONGARCH_CSR_BADI);
58 	set_gcsr_hw_flag(LOONGARCH_CSR_EENTRY);
59 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBIDX);
60 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBEHI);
61 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBELO0);
62 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBELO1);
63 	set_gcsr_hw_flag(LOONGARCH_CSR_ASID);
64 	set_gcsr_hw_flag(LOONGARCH_CSR_PGDL);
65 	set_gcsr_hw_flag(LOONGARCH_CSR_PGDH);
66 	set_gcsr_hw_flag(LOONGARCH_CSR_PGD);
67 	set_gcsr_hw_flag(LOONGARCH_CSR_PWCTL0);
68 	set_gcsr_hw_flag(LOONGARCH_CSR_PWCTL1);
69 	set_gcsr_hw_flag(LOONGARCH_CSR_STLBPGSIZE);
70 	set_gcsr_hw_flag(LOONGARCH_CSR_RVACFG);
71 	set_gcsr_hw_flag(LOONGARCH_CSR_CPUID);
72 	set_gcsr_hw_flag(LOONGARCH_CSR_PRCFG1);
73 	set_gcsr_hw_flag(LOONGARCH_CSR_PRCFG2);
74 	set_gcsr_hw_flag(LOONGARCH_CSR_PRCFG3);
75 	set_gcsr_hw_flag(LOONGARCH_CSR_KS0);
76 	set_gcsr_hw_flag(LOONGARCH_CSR_KS1);
77 	set_gcsr_hw_flag(LOONGARCH_CSR_KS2);
78 	set_gcsr_hw_flag(LOONGARCH_CSR_KS3);
79 	set_gcsr_hw_flag(LOONGARCH_CSR_KS4);
80 	set_gcsr_hw_flag(LOONGARCH_CSR_KS5);
81 	set_gcsr_hw_flag(LOONGARCH_CSR_KS6);
82 	set_gcsr_hw_flag(LOONGARCH_CSR_KS7);
83 	set_gcsr_hw_flag(LOONGARCH_CSR_TMID);
84 	set_gcsr_hw_flag(LOONGARCH_CSR_TCFG);
85 	set_gcsr_hw_flag(LOONGARCH_CSR_TVAL);
86 	set_gcsr_hw_flag(LOONGARCH_CSR_TINTCLR);
87 	set_gcsr_hw_flag(LOONGARCH_CSR_CNTC);
88 	set_gcsr_hw_flag(LOONGARCH_CSR_LLBCTL);
89 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRENTRY);
90 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRBADV);
91 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRERA);
92 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRSAVE);
93 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRELO0);
94 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRELO1);
95 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBREHI);
96 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRPRMD);
97 	set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN0);
98 	set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN1);
99 	set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN2);
100 	set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN3);
101 
102 	set_gcsr_sw_flag(LOONGARCH_CSR_IMPCTL1);
103 	set_gcsr_sw_flag(LOONGARCH_CSR_IMPCTL2);
104 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRCTL);
105 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRINFO1);
106 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRINFO2);
107 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRENTRY);
108 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRERA);
109 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRSAVE);
110 	set_gcsr_sw_flag(LOONGARCH_CSR_CTAG);
111 	set_gcsr_sw_flag(LOONGARCH_CSR_DEBUG);
112 	set_gcsr_sw_flag(LOONGARCH_CSR_DERA);
113 	set_gcsr_sw_flag(LOONGARCH_CSR_DESAVE);
114 
115 	set_gcsr_sw_flag(LOONGARCH_CSR_FWPC);
116 	set_gcsr_sw_flag(LOONGARCH_CSR_FWPS);
117 	set_gcsr_sw_flag(LOONGARCH_CSR_MWPC);
118 	set_gcsr_sw_flag(LOONGARCH_CSR_MWPS);
119 
120 	set_gcsr_sw_flag(LOONGARCH_CSR_DB0ADDR);
121 	set_gcsr_sw_flag(LOONGARCH_CSR_DB0MASK);
122 	set_gcsr_sw_flag(LOONGARCH_CSR_DB0CTRL);
123 	set_gcsr_sw_flag(LOONGARCH_CSR_DB0ASID);
124 	set_gcsr_sw_flag(LOONGARCH_CSR_DB1ADDR);
125 	set_gcsr_sw_flag(LOONGARCH_CSR_DB1MASK);
126 	set_gcsr_sw_flag(LOONGARCH_CSR_DB1CTRL);
127 	set_gcsr_sw_flag(LOONGARCH_CSR_DB1ASID);
128 	set_gcsr_sw_flag(LOONGARCH_CSR_DB2ADDR);
129 	set_gcsr_sw_flag(LOONGARCH_CSR_DB2MASK);
130 	set_gcsr_sw_flag(LOONGARCH_CSR_DB2CTRL);
131 	set_gcsr_sw_flag(LOONGARCH_CSR_DB2ASID);
132 	set_gcsr_sw_flag(LOONGARCH_CSR_DB3ADDR);
133 	set_gcsr_sw_flag(LOONGARCH_CSR_DB3MASK);
134 	set_gcsr_sw_flag(LOONGARCH_CSR_DB3CTRL);
135 	set_gcsr_sw_flag(LOONGARCH_CSR_DB3ASID);
136 	set_gcsr_sw_flag(LOONGARCH_CSR_DB4ADDR);
137 	set_gcsr_sw_flag(LOONGARCH_CSR_DB4MASK);
138 	set_gcsr_sw_flag(LOONGARCH_CSR_DB4CTRL);
139 	set_gcsr_sw_flag(LOONGARCH_CSR_DB4ASID);
140 	set_gcsr_sw_flag(LOONGARCH_CSR_DB5ADDR);
141 	set_gcsr_sw_flag(LOONGARCH_CSR_DB5MASK);
142 	set_gcsr_sw_flag(LOONGARCH_CSR_DB5CTRL);
143 	set_gcsr_sw_flag(LOONGARCH_CSR_DB5ASID);
144 	set_gcsr_sw_flag(LOONGARCH_CSR_DB6ADDR);
145 	set_gcsr_sw_flag(LOONGARCH_CSR_DB6MASK);
146 	set_gcsr_sw_flag(LOONGARCH_CSR_DB6CTRL);
147 	set_gcsr_sw_flag(LOONGARCH_CSR_DB6ASID);
148 	set_gcsr_sw_flag(LOONGARCH_CSR_DB7ADDR);
149 	set_gcsr_sw_flag(LOONGARCH_CSR_DB7MASK);
150 	set_gcsr_sw_flag(LOONGARCH_CSR_DB7CTRL);
151 	set_gcsr_sw_flag(LOONGARCH_CSR_DB7ASID);
152 
153 	set_gcsr_sw_flag(LOONGARCH_CSR_IB0ADDR);
154 	set_gcsr_sw_flag(LOONGARCH_CSR_IB0MASK);
155 	set_gcsr_sw_flag(LOONGARCH_CSR_IB0CTRL);
156 	set_gcsr_sw_flag(LOONGARCH_CSR_IB0ASID);
157 	set_gcsr_sw_flag(LOONGARCH_CSR_IB1ADDR);
158 	set_gcsr_sw_flag(LOONGARCH_CSR_IB1MASK);
159 	set_gcsr_sw_flag(LOONGARCH_CSR_IB1CTRL);
160 	set_gcsr_sw_flag(LOONGARCH_CSR_IB1ASID);
161 	set_gcsr_sw_flag(LOONGARCH_CSR_IB2ADDR);
162 	set_gcsr_sw_flag(LOONGARCH_CSR_IB2MASK);
163 	set_gcsr_sw_flag(LOONGARCH_CSR_IB2CTRL);
164 	set_gcsr_sw_flag(LOONGARCH_CSR_IB2ASID);
165 	set_gcsr_sw_flag(LOONGARCH_CSR_IB3ADDR);
166 	set_gcsr_sw_flag(LOONGARCH_CSR_IB3MASK);
167 	set_gcsr_sw_flag(LOONGARCH_CSR_IB3CTRL);
168 	set_gcsr_sw_flag(LOONGARCH_CSR_IB3ASID);
169 	set_gcsr_sw_flag(LOONGARCH_CSR_IB4ADDR);
170 	set_gcsr_sw_flag(LOONGARCH_CSR_IB4MASK);
171 	set_gcsr_sw_flag(LOONGARCH_CSR_IB4CTRL);
172 	set_gcsr_sw_flag(LOONGARCH_CSR_IB4ASID);
173 	set_gcsr_sw_flag(LOONGARCH_CSR_IB5ADDR);
174 	set_gcsr_sw_flag(LOONGARCH_CSR_IB5MASK);
175 	set_gcsr_sw_flag(LOONGARCH_CSR_IB5CTRL);
176 	set_gcsr_sw_flag(LOONGARCH_CSR_IB5ASID);
177 	set_gcsr_sw_flag(LOONGARCH_CSR_IB6ADDR);
178 	set_gcsr_sw_flag(LOONGARCH_CSR_IB6MASK);
179 	set_gcsr_sw_flag(LOONGARCH_CSR_IB6CTRL);
180 	set_gcsr_sw_flag(LOONGARCH_CSR_IB6ASID);
181 	set_gcsr_sw_flag(LOONGARCH_CSR_IB7ADDR);
182 	set_gcsr_sw_flag(LOONGARCH_CSR_IB7MASK);
183 	set_gcsr_sw_flag(LOONGARCH_CSR_IB7CTRL);
184 	set_gcsr_sw_flag(LOONGARCH_CSR_IB7ASID);
185 
186 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL0);
187 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR0);
188 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL1);
189 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR1);
190 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL2);
191 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR2);
192 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL3);
193 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR3);
194 }
195 
196 static void kvm_update_vpid(struct kvm_vcpu *vcpu, int cpu)
197 {
198 	unsigned long vpid;
199 	struct kvm_context *context;
200 
201 	context = per_cpu_ptr(vcpu->kvm->arch.vmcs, cpu);
202 	vpid = context->vpid_cache + 1;
203 	if (!(vpid & vpid_mask)) {
204 		/* finish round of vpid loop */
205 		if (unlikely(!vpid))
206 			vpid = vpid_mask + 1;
207 
208 		++vpid; /* vpid 0 reserved for root */
209 
210 		/* start new vpid cycle */
211 		kvm_flush_tlb_all();
212 	}
213 
214 	context->vpid_cache = vpid;
215 	vcpu->arch.vpid = vpid;
216 }
217 
218 void kvm_check_vpid(struct kvm_vcpu *vcpu)
219 {
220 	int cpu;
221 	bool migrated;
222 	unsigned long ver, old, vpid;
223 	struct kvm_context *context;
224 
225 	cpu = smp_processor_id();
226 	/*
227 	 * Are we entering guest context on a different CPU to last time?
228 	 * If so, the vCPU's guest TLB state on this CPU may be stale.
229 	 */
230 	context = per_cpu_ptr(vcpu->kvm->arch.vmcs, cpu);
231 	migrated = (vcpu->cpu != cpu);
232 
233 	/*
234 	 * Check if our vpid is of an older version
235 	 *
236 	 * We also discard the stored vpid if we've executed on
237 	 * another CPU, as the guest mappings may have changed without
238 	 * hypervisor knowledge.
239 	 */
240 	ver = vcpu->arch.vpid & ~vpid_mask;
241 	old = context->vpid_cache  & ~vpid_mask;
242 	if (migrated || (ver != old)) {
243 		kvm_update_vpid(vcpu, cpu);
244 		trace_kvm_vpid_change(vcpu, vcpu->arch.vpid);
245 		vcpu->cpu = cpu;
246 		kvm_clear_request(KVM_REQ_TLB_FLUSH_GPA, vcpu);
247 	}
248 
249 	/* Restore GSTAT(0x50).vpid */
250 	vpid = (vcpu->arch.vpid & vpid_mask) << CSR_GSTAT_GID_SHIFT;
251 	change_csr_gstat(vpid_mask << CSR_GSTAT_GID_SHIFT, vpid);
252 }
253 
254 void kvm_init_vmcs(struct kvm *kvm)
255 {
256 	kvm->arch.vmcs = vmcs;
257 }
258 
259 long kvm_arch_dev_ioctl(struct file *filp,
260 			unsigned int ioctl, unsigned long arg)
261 {
262 	return -ENOIOCTLCMD;
263 }
264 
265 int kvm_arch_enable_virtualization_cpu(void)
266 {
267 	unsigned long env, gcfg = 0;
268 
269 	env = read_csr_gcfg();
270 
271 	/* First init gcfg, gstat, gintc, gtlbc. All guest use the same config */
272 	write_csr_gcfg(0);
273 	write_csr_gstat(0);
274 	write_csr_gintc(0);
275 	clear_csr_gtlbc(CSR_GTLBC_USETGID | CSR_GTLBC_TOTI);
276 
277 	/*
278 	 * Enable virtualization features granting guest direct control of
279 	 * certain features:
280 	 * GCI=2:       Trap on init or unimplement cache instruction.
281 	 * TORU=0:      Trap on Root Unimplement.
282 	 * CACTRL=1:    Root control cache.
283 	 * TOP=0:       Trap on Previlege.
284 	 * TOE=0:       Trap on Exception.
285 	 * TIT=0:       Trap on Timer.
286 	 */
287 	if (env & CSR_GCFG_GCIP_ALL)
288 		gcfg |= CSR_GCFG_GCI_SECURE;
289 	if (env & CSR_GCFG_MATC_ROOT)
290 		gcfg |= CSR_GCFG_MATC_ROOT;
291 
292 	write_csr_gcfg(gcfg);
293 
294 	kvm_flush_tlb_all();
295 
296 	/* Enable using TGID  */
297 	set_csr_gtlbc(CSR_GTLBC_USETGID);
298 	kvm_debug("GCFG:%lx GSTAT:%lx GINTC:%lx GTLBC:%lx",
299 		  read_csr_gcfg(), read_csr_gstat(), read_csr_gintc(), read_csr_gtlbc());
300 
301 	return 0;
302 }
303 
304 void kvm_arch_disable_virtualization_cpu(void)
305 {
306 	write_csr_gcfg(0);
307 	write_csr_gstat(0);
308 	write_csr_gintc(0);
309 	clear_csr_gtlbc(CSR_GTLBC_USETGID | CSR_GTLBC_TOTI);
310 
311 	/* Flush any remaining guest TLB entries */
312 	kvm_flush_tlb_all();
313 }
314 
315 static int kvm_loongarch_env_init(void)
316 {
317 	int cpu, order, ret;
318 	void *addr;
319 	struct kvm_context *context;
320 
321 	vmcs = alloc_percpu(struct kvm_context);
322 	if (!vmcs) {
323 		pr_err("kvm: failed to allocate percpu kvm_context\n");
324 		return -ENOMEM;
325 	}
326 
327 	kvm_loongarch_ops = kzalloc(sizeof(*kvm_loongarch_ops), GFP_KERNEL);
328 	if (!kvm_loongarch_ops) {
329 		free_percpu(vmcs);
330 		vmcs = NULL;
331 		return -ENOMEM;
332 	}
333 
334 	/*
335 	 * PGD register is shared between root kernel and kvm hypervisor.
336 	 * So world switch entry should be in DMW area rather than TLB area
337 	 * to avoid page fault reenter.
338 	 *
339 	 * In future if hardware pagetable walking is supported, we won't
340 	 * need to copy world switch code to DMW area.
341 	 */
342 	order = get_order(kvm_exception_size + kvm_enter_guest_size);
343 	addr = (void *)__get_free_pages(GFP_KERNEL, order);
344 	if (!addr) {
345 		free_percpu(vmcs);
346 		vmcs = NULL;
347 		kfree(kvm_loongarch_ops);
348 		kvm_loongarch_ops = NULL;
349 		return -ENOMEM;
350 	}
351 
352 	memcpy(addr, kvm_exc_entry, kvm_exception_size);
353 	memcpy(addr + kvm_exception_size, kvm_enter_guest, kvm_enter_guest_size);
354 	flush_icache_range((unsigned long)addr, (unsigned long)addr + kvm_exception_size + kvm_enter_guest_size);
355 	kvm_loongarch_ops->exc_entry = addr;
356 	kvm_loongarch_ops->enter_guest = addr + kvm_exception_size;
357 	kvm_loongarch_ops->page_order = order;
358 
359 	vpid_mask = read_csr_gstat();
360 	vpid_mask = (vpid_mask & CSR_GSTAT_GIDBIT) >> CSR_GSTAT_GIDBIT_SHIFT;
361 	if (vpid_mask)
362 		vpid_mask = GENMASK(vpid_mask - 1, 0);
363 
364 	for_each_possible_cpu(cpu) {
365 		context = per_cpu_ptr(vmcs, cpu);
366 		context->vpid_cache = vpid_mask + 1;
367 		context->last_vcpu = NULL;
368 	}
369 
370 	kvm_init_gcsr_flag();
371 
372 	/* Register LoongArch IPI interrupt controller interface. */
373 	ret = kvm_loongarch_register_ipi_device();
374 	if (ret)
375 		return ret;
376 
377 	/* Register LoongArch EIOINTC interrupt controller interface. */
378 	ret = kvm_loongarch_register_eiointc_device();
379 
380 	return ret;
381 }
382 
383 static void kvm_loongarch_env_exit(void)
384 {
385 	unsigned long addr;
386 
387 	if (vmcs)
388 		free_percpu(vmcs);
389 
390 	if (kvm_loongarch_ops) {
391 		if (kvm_loongarch_ops->exc_entry) {
392 			addr = (unsigned long)kvm_loongarch_ops->exc_entry;
393 			free_pages(addr, kvm_loongarch_ops->page_order);
394 		}
395 		kfree(kvm_loongarch_ops);
396 	}
397 }
398 
399 static int kvm_loongarch_init(void)
400 {
401 	int r;
402 
403 	if (!cpu_has_lvz) {
404 		kvm_info("Hardware virtualization not available\n");
405 		return -ENODEV;
406 	}
407 	r = kvm_loongarch_env_init();
408 	if (r)
409 		return r;
410 
411 	return kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
412 }
413 
414 static void kvm_loongarch_exit(void)
415 {
416 	kvm_exit();
417 	kvm_loongarch_env_exit();
418 }
419 
420 module_init(kvm_loongarch_init);
421 module_exit(kvm_loongarch_exit);
422 
423 #ifdef MODULE
424 static const struct cpu_feature kvm_feature[] = {
425 	{ .feature = cpu_feature(LOONGARCH_LVZ) },
426 	{},
427 };
428 MODULE_DEVICE_TABLE(cpu, kvm_feature);
429 #endif
430