xref: /linux/arch/loongarch/kvm/main.c (revision 7f4f3b14e8079ecde096bd734af10e30d40c27b7)
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 <asm/kvm_pch_pic.h>
14 #include "trace.h"
15 
16 unsigned long vpid_mask;
17 struct kvm_world_switch *kvm_loongarch_ops;
18 static int gcsr_flag[CSR_MAX_NUMS];
19 static struct kvm_context __percpu *vmcs;
20 
21 int get_gcsr_flag(int csr)
22 {
23 	if (csr < CSR_MAX_NUMS)
24 		return gcsr_flag[csr];
25 
26 	return INVALID_GCSR;
27 }
28 
29 static inline void set_gcsr_sw_flag(int csr)
30 {
31 	if (csr < CSR_MAX_NUMS)
32 		gcsr_flag[csr] |= SW_GCSR;
33 }
34 
35 static inline void set_gcsr_hw_flag(int csr)
36 {
37 	if (csr < CSR_MAX_NUMS)
38 		gcsr_flag[csr] |= HW_GCSR;
39 }
40 
41 /*
42  * The default value of gcsr_flag[CSR] is 0, and we use this
43  * function to set the flag to 1 (SW_GCSR) or 2 (HW_GCSR) if the
44  * gcsr is software or hardware. It will be used by get/set_gcsr,
45  * if gcsr_flag is HW we should use gcsrrd/gcsrwr to access it,
46  * else use software csr to emulate it.
47  */
48 static void kvm_init_gcsr_flag(void)
49 {
50 	set_gcsr_hw_flag(LOONGARCH_CSR_CRMD);
51 	set_gcsr_hw_flag(LOONGARCH_CSR_PRMD);
52 	set_gcsr_hw_flag(LOONGARCH_CSR_EUEN);
53 	set_gcsr_hw_flag(LOONGARCH_CSR_MISC);
54 	set_gcsr_hw_flag(LOONGARCH_CSR_ECFG);
55 	set_gcsr_hw_flag(LOONGARCH_CSR_ESTAT);
56 	set_gcsr_hw_flag(LOONGARCH_CSR_ERA);
57 	set_gcsr_hw_flag(LOONGARCH_CSR_BADV);
58 	set_gcsr_hw_flag(LOONGARCH_CSR_BADI);
59 	set_gcsr_hw_flag(LOONGARCH_CSR_EENTRY);
60 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBIDX);
61 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBEHI);
62 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBELO0);
63 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBELO1);
64 	set_gcsr_hw_flag(LOONGARCH_CSR_ASID);
65 	set_gcsr_hw_flag(LOONGARCH_CSR_PGDL);
66 	set_gcsr_hw_flag(LOONGARCH_CSR_PGDH);
67 	set_gcsr_hw_flag(LOONGARCH_CSR_PGD);
68 	set_gcsr_hw_flag(LOONGARCH_CSR_PWCTL0);
69 	set_gcsr_hw_flag(LOONGARCH_CSR_PWCTL1);
70 	set_gcsr_hw_flag(LOONGARCH_CSR_STLBPGSIZE);
71 	set_gcsr_hw_flag(LOONGARCH_CSR_RVACFG);
72 	set_gcsr_hw_flag(LOONGARCH_CSR_CPUID);
73 	set_gcsr_hw_flag(LOONGARCH_CSR_PRCFG1);
74 	set_gcsr_hw_flag(LOONGARCH_CSR_PRCFG2);
75 	set_gcsr_hw_flag(LOONGARCH_CSR_PRCFG3);
76 	set_gcsr_hw_flag(LOONGARCH_CSR_KS0);
77 	set_gcsr_hw_flag(LOONGARCH_CSR_KS1);
78 	set_gcsr_hw_flag(LOONGARCH_CSR_KS2);
79 	set_gcsr_hw_flag(LOONGARCH_CSR_KS3);
80 	set_gcsr_hw_flag(LOONGARCH_CSR_KS4);
81 	set_gcsr_hw_flag(LOONGARCH_CSR_KS5);
82 	set_gcsr_hw_flag(LOONGARCH_CSR_KS6);
83 	set_gcsr_hw_flag(LOONGARCH_CSR_KS7);
84 	set_gcsr_hw_flag(LOONGARCH_CSR_TMID);
85 	set_gcsr_hw_flag(LOONGARCH_CSR_TCFG);
86 	set_gcsr_hw_flag(LOONGARCH_CSR_TVAL);
87 	set_gcsr_hw_flag(LOONGARCH_CSR_TINTCLR);
88 	set_gcsr_hw_flag(LOONGARCH_CSR_CNTC);
89 	set_gcsr_hw_flag(LOONGARCH_CSR_LLBCTL);
90 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRENTRY);
91 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRBADV);
92 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRERA);
93 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRSAVE);
94 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRELO0);
95 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRELO1);
96 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBREHI);
97 	set_gcsr_hw_flag(LOONGARCH_CSR_TLBRPRMD);
98 	set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN0);
99 	set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN1);
100 	set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN2);
101 	set_gcsr_hw_flag(LOONGARCH_CSR_DMWIN3);
102 
103 	set_gcsr_sw_flag(LOONGARCH_CSR_IMPCTL1);
104 	set_gcsr_sw_flag(LOONGARCH_CSR_IMPCTL2);
105 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRCTL);
106 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRINFO1);
107 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRINFO2);
108 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRENTRY);
109 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRERA);
110 	set_gcsr_sw_flag(LOONGARCH_CSR_MERRSAVE);
111 	set_gcsr_sw_flag(LOONGARCH_CSR_CTAG);
112 	set_gcsr_sw_flag(LOONGARCH_CSR_DEBUG);
113 	set_gcsr_sw_flag(LOONGARCH_CSR_DERA);
114 	set_gcsr_sw_flag(LOONGARCH_CSR_DESAVE);
115 
116 	set_gcsr_sw_flag(LOONGARCH_CSR_FWPC);
117 	set_gcsr_sw_flag(LOONGARCH_CSR_FWPS);
118 	set_gcsr_sw_flag(LOONGARCH_CSR_MWPC);
119 	set_gcsr_sw_flag(LOONGARCH_CSR_MWPS);
120 
121 	set_gcsr_sw_flag(LOONGARCH_CSR_DB0ADDR);
122 	set_gcsr_sw_flag(LOONGARCH_CSR_DB0MASK);
123 	set_gcsr_sw_flag(LOONGARCH_CSR_DB0CTRL);
124 	set_gcsr_sw_flag(LOONGARCH_CSR_DB0ASID);
125 	set_gcsr_sw_flag(LOONGARCH_CSR_DB1ADDR);
126 	set_gcsr_sw_flag(LOONGARCH_CSR_DB1MASK);
127 	set_gcsr_sw_flag(LOONGARCH_CSR_DB1CTRL);
128 	set_gcsr_sw_flag(LOONGARCH_CSR_DB1ASID);
129 	set_gcsr_sw_flag(LOONGARCH_CSR_DB2ADDR);
130 	set_gcsr_sw_flag(LOONGARCH_CSR_DB2MASK);
131 	set_gcsr_sw_flag(LOONGARCH_CSR_DB2CTRL);
132 	set_gcsr_sw_flag(LOONGARCH_CSR_DB2ASID);
133 	set_gcsr_sw_flag(LOONGARCH_CSR_DB3ADDR);
134 	set_gcsr_sw_flag(LOONGARCH_CSR_DB3MASK);
135 	set_gcsr_sw_flag(LOONGARCH_CSR_DB3CTRL);
136 	set_gcsr_sw_flag(LOONGARCH_CSR_DB3ASID);
137 	set_gcsr_sw_flag(LOONGARCH_CSR_DB4ADDR);
138 	set_gcsr_sw_flag(LOONGARCH_CSR_DB4MASK);
139 	set_gcsr_sw_flag(LOONGARCH_CSR_DB4CTRL);
140 	set_gcsr_sw_flag(LOONGARCH_CSR_DB4ASID);
141 	set_gcsr_sw_flag(LOONGARCH_CSR_DB5ADDR);
142 	set_gcsr_sw_flag(LOONGARCH_CSR_DB5MASK);
143 	set_gcsr_sw_flag(LOONGARCH_CSR_DB5CTRL);
144 	set_gcsr_sw_flag(LOONGARCH_CSR_DB5ASID);
145 	set_gcsr_sw_flag(LOONGARCH_CSR_DB6ADDR);
146 	set_gcsr_sw_flag(LOONGARCH_CSR_DB6MASK);
147 	set_gcsr_sw_flag(LOONGARCH_CSR_DB6CTRL);
148 	set_gcsr_sw_flag(LOONGARCH_CSR_DB6ASID);
149 	set_gcsr_sw_flag(LOONGARCH_CSR_DB7ADDR);
150 	set_gcsr_sw_flag(LOONGARCH_CSR_DB7MASK);
151 	set_gcsr_sw_flag(LOONGARCH_CSR_DB7CTRL);
152 	set_gcsr_sw_flag(LOONGARCH_CSR_DB7ASID);
153 
154 	set_gcsr_sw_flag(LOONGARCH_CSR_IB0ADDR);
155 	set_gcsr_sw_flag(LOONGARCH_CSR_IB0MASK);
156 	set_gcsr_sw_flag(LOONGARCH_CSR_IB0CTRL);
157 	set_gcsr_sw_flag(LOONGARCH_CSR_IB0ASID);
158 	set_gcsr_sw_flag(LOONGARCH_CSR_IB1ADDR);
159 	set_gcsr_sw_flag(LOONGARCH_CSR_IB1MASK);
160 	set_gcsr_sw_flag(LOONGARCH_CSR_IB1CTRL);
161 	set_gcsr_sw_flag(LOONGARCH_CSR_IB1ASID);
162 	set_gcsr_sw_flag(LOONGARCH_CSR_IB2ADDR);
163 	set_gcsr_sw_flag(LOONGARCH_CSR_IB2MASK);
164 	set_gcsr_sw_flag(LOONGARCH_CSR_IB2CTRL);
165 	set_gcsr_sw_flag(LOONGARCH_CSR_IB2ASID);
166 	set_gcsr_sw_flag(LOONGARCH_CSR_IB3ADDR);
167 	set_gcsr_sw_flag(LOONGARCH_CSR_IB3MASK);
168 	set_gcsr_sw_flag(LOONGARCH_CSR_IB3CTRL);
169 	set_gcsr_sw_flag(LOONGARCH_CSR_IB3ASID);
170 	set_gcsr_sw_flag(LOONGARCH_CSR_IB4ADDR);
171 	set_gcsr_sw_flag(LOONGARCH_CSR_IB4MASK);
172 	set_gcsr_sw_flag(LOONGARCH_CSR_IB4CTRL);
173 	set_gcsr_sw_flag(LOONGARCH_CSR_IB4ASID);
174 	set_gcsr_sw_flag(LOONGARCH_CSR_IB5ADDR);
175 	set_gcsr_sw_flag(LOONGARCH_CSR_IB5MASK);
176 	set_gcsr_sw_flag(LOONGARCH_CSR_IB5CTRL);
177 	set_gcsr_sw_flag(LOONGARCH_CSR_IB5ASID);
178 	set_gcsr_sw_flag(LOONGARCH_CSR_IB6ADDR);
179 	set_gcsr_sw_flag(LOONGARCH_CSR_IB6MASK);
180 	set_gcsr_sw_flag(LOONGARCH_CSR_IB6CTRL);
181 	set_gcsr_sw_flag(LOONGARCH_CSR_IB6ASID);
182 	set_gcsr_sw_flag(LOONGARCH_CSR_IB7ADDR);
183 	set_gcsr_sw_flag(LOONGARCH_CSR_IB7MASK);
184 	set_gcsr_sw_flag(LOONGARCH_CSR_IB7CTRL);
185 	set_gcsr_sw_flag(LOONGARCH_CSR_IB7ASID);
186 
187 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL0);
188 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR0);
189 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL1);
190 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR1);
191 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL2);
192 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR2);
193 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCTRL3);
194 	set_gcsr_sw_flag(LOONGARCH_CSR_PERFCNTR3);
195 }
196 
197 static void kvm_update_vpid(struct kvm_vcpu *vcpu, int cpu)
198 {
199 	unsigned long vpid;
200 	struct kvm_context *context;
201 
202 	context = per_cpu_ptr(vcpu->kvm->arch.vmcs, cpu);
203 	vpid = context->vpid_cache + 1;
204 	if (!(vpid & vpid_mask)) {
205 		/* finish round of vpid loop */
206 		if (unlikely(!vpid))
207 			vpid = vpid_mask + 1;
208 
209 		++vpid; /* vpid 0 reserved for root */
210 
211 		/* start new vpid cycle */
212 		kvm_flush_tlb_all();
213 	}
214 
215 	context->vpid_cache = vpid;
216 	vcpu->arch.vpid = vpid;
217 }
218 
219 void kvm_check_vpid(struct kvm_vcpu *vcpu)
220 {
221 	int cpu;
222 	bool migrated;
223 	unsigned long ver, old, vpid;
224 	struct kvm_context *context;
225 
226 	cpu = smp_processor_id();
227 	/*
228 	 * Are we entering guest context on a different CPU to last time?
229 	 * If so, the vCPU's guest TLB state on this CPU may be stale.
230 	 */
231 	context = per_cpu_ptr(vcpu->kvm->arch.vmcs, cpu);
232 	migrated = (vcpu->cpu != cpu);
233 
234 	/*
235 	 * Check if our vpid is of an older version
236 	 *
237 	 * We also discard the stored vpid if we've executed on
238 	 * another CPU, as the guest mappings may have changed without
239 	 * hypervisor knowledge.
240 	 */
241 	ver = vcpu->arch.vpid & ~vpid_mask;
242 	old = context->vpid_cache  & ~vpid_mask;
243 	if (migrated || (ver != old)) {
244 		kvm_update_vpid(vcpu, cpu);
245 		trace_kvm_vpid_change(vcpu, vcpu->arch.vpid);
246 		vcpu->cpu = cpu;
247 		kvm_clear_request(KVM_REQ_TLB_FLUSH_GPA, vcpu);
248 	}
249 
250 	/* Restore GSTAT(0x50).vpid */
251 	vpid = (vcpu->arch.vpid & vpid_mask) << CSR_GSTAT_GID_SHIFT;
252 	change_csr_gstat(vpid_mask << CSR_GSTAT_GID_SHIFT, vpid);
253 }
254 
255 void kvm_init_vmcs(struct kvm *kvm)
256 {
257 	kvm->arch.vmcs = vmcs;
258 }
259 
260 long kvm_arch_dev_ioctl(struct file *filp,
261 			unsigned int ioctl, unsigned long arg)
262 {
263 	return -ENOIOCTLCMD;
264 }
265 
266 int kvm_arch_enable_virtualization_cpu(void)
267 {
268 	unsigned long env, gcfg = 0;
269 
270 	env = read_csr_gcfg();
271 
272 	/* First init gcfg, gstat, gintc, gtlbc. All guest use the same config */
273 	write_csr_gcfg(0);
274 	write_csr_gstat(0);
275 	write_csr_gintc(0);
276 	clear_csr_gtlbc(CSR_GTLBC_USETGID | CSR_GTLBC_TOTI);
277 
278 	/*
279 	 * Enable virtualization features granting guest direct control of
280 	 * certain features:
281 	 * GCI=2:       Trap on init or unimplement cache instruction.
282 	 * TORU=0:      Trap on Root Unimplement.
283 	 * CACTRL=1:    Root control cache.
284 	 * TOP=0:       Trap on Previlege.
285 	 * TOE=0:       Trap on Exception.
286 	 * TIT=0:       Trap on Timer.
287 	 */
288 	if (env & CSR_GCFG_GCIP_ALL)
289 		gcfg |= CSR_GCFG_GCI_SECURE;
290 	if (env & CSR_GCFG_MATC_ROOT)
291 		gcfg |= CSR_GCFG_MATC_ROOT;
292 
293 	write_csr_gcfg(gcfg);
294 
295 	kvm_flush_tlb_all();
296 
297 	/* Enable using TGID  */
298 	set_csr_gtlbc(CSR_GTLBC_USETGID);
299 	kvm_debug("GCFG:%lx GSTAT:%lx GINTC:%lx GTLBC:%lx",
300 		  read_csr_gcfg(), read_csr_gstat(), read_csr_gintc(), read_csr_gtlbc());
301 
302 	return 0;
303 }
304 
305 void kvm_arch_disable_virtualization_cpu(void)
306 {
307 	write_csr_gcfg(0);
308 	write_csr_gstat(0);
309 	write_csr_gintc(0);
310 	clear_csr_gtlbc(CSR_GTLBC_USETGID | CSR_GTLBC_TOTI);
311 
312 	/* Flush any remaining guest TLB entries */
313 	kvm_flush_tlb_all();
314 }
315 
316 static int kvm_loongarch_env_init(void)
317 {
318 	int cpu, order, ret;
319 	void *addr;
320 	struct kvm_context *context;
321 
322 	vmcs = alloc_percpu(struct kvm_context);
323 	if (!vmcs) {
324 		pr_err("kvm: failed to allocate percpu kvm_context\n");
325 		return -ENOMEM;
326 	}
327 
328 	kvm_loongarch_ops = kzalloc(sizeof(*kvm_loongarch_ops), GFP_KERNEL);
329 	if (!kvm_loongarch_ops) {
330 		free_percpu(vmcs);
331 		vmcs = NULL;
332 		return -ENOMEM;
333 	}
334 
335 	/*
336 	 * PGD register is shared between root kernel and kvm hypervisor.
337 	 * So world switch entry should be in DMW area rather than TLB area
338 	 * to avoid page fault reenter.
339 	 *
340 	 * In future if hardware pagetable walking is supported, we won't
341 	 * need to copy world switch code to DMW area.
342 	 */
343 	order = get_order(kvm_exception_size + kvm_enter_guest_size);
344 	addr = (void *)__get_free_pages(GFP_KERNEL, order);
345 	if (!addr) {
346 		free_percpu(vmcs);
347 		vmcs = NULL;
348 		kfree(kvm_loongarch_ops);
349 		kvm_loongarch_ops = NULL;
350 		return -ENOMEM;
351 	}
352 
353 	memcpy(addr, kvm_exc_entry, kvm_exception_size);
354 	memcpy(addr + kvm_exception_size, kvm_enter_guest, kvm_enter_guest_size);
355 	flush_icache_range((unsigned long)addr, (unsigned long)addr + kvm_exception_size + kvm_enter_guest_size);
356 	kvm_loongarch_ops->exc_entry = addr;
357 	kvm_loongarch_ops->enter_guest = addr + kvm_exception_size;
358 	kvm_loongarch_ops->page_order = order;
359 
360 	vpid_mask = read_csr_gstat();
361 	vpid_mask = (vpid_mask & CSR_GSTAT_GIDBIT) >> CSR_GSTAT_GIDBIT_SHIFT;
362 	if (vpid_mask)
363 		vpid_mask = GENMASK(vpid_mask - 1, 0);
364 
365 	for_each_possible_cpu(cpu) {
366 		context = per_cpu_ptr(vmcs, cpu);
367 		context->vpid_cache = vpid_mask + 1;
368 		context->last_vcpu = NULL;
369 	}
370 
371 	kvm_init_gcsr_flag();
372 
373 	/* Register LoongArch IPI interrupt controller interface. */
374 	ret = kvm_loongarch_register_ipi_device();
375 	if (ret)
376 		return ret;
377 
378 	/* Register LoongArch EIOINTC interrupt controller interface. */
379 	ret = kvm_loongarch_register_eiointc_device();
380 	if (ret)
381 		return ret;
382 
383 	/* Register LoongArch PCH-PIC interrupt controller interface. */
384 	ret = kvm_loongarch_register_pch_pic_device();
385 
386 	return ret;
387 }
388 
389 static void kvm_loongarch_env_exit(void)
390 {
391 	unsigned long addr;
392 
393 	if (vmcs)
394 		free_percpu(vmcs);
395 
396 	if (kvm_loongarch_ops) {
397 		if (kvm_loongarch_ops->exc_entry) {
398 			addr = (unsigned long)kvm_loongarch_ops->exc_entry;
399 			free_pages(addr, kvm_loongarch_ops->page_order);
400 		}
401 		kfree(kvm_loongarch_ops);
402 	}
403 }
404 
405 static int kvm_loongarch_init(void)
406 {
407 	int r;
408 
409 	if (!cpu_has_lvz) {
410 		kvm_info("Hardware virtualization not available\n");
411 		return -ENODEV;
412 	}
413 	r = kvm_loongarch_env_init();
414 	if (r)
415 		return r;
416 
417 	return kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
418 }
419 
420 static void kvm_loongarch_exit(void)
421 {
422 	kvm_exit();
423 	kvm_loongarch_env_exit();
424 }
425 
426 module_init(kvm_loongarch_init);
427 module_exit(kvm_loongarch_exit);
428 
429 #ifdef MODULE
430 static const struct cpu_feature kvm_feature[] = {
431 	{ .feature = cpu_feature(LOONGARCH_LVZ) },
432 	{},
433 };
434 MODULE_DEVICE_TABLE(cpu, kvm_feature);
435 #endif
436