xref: /openbmc/linux/arch/arm64/kvm/hyp/nvhe/hyp-main.c (revision 6db6b729)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2020 - Google Inc
4  * Author: Andrew Scull <ascull@google.com>
5  */
6 
7 #include <hyp/adjust_pc.h>
8 
9 #include <asm/pgtable-types.h>
10 #include <asm/kvm_asm.h>
11 #include <asm/kvm_emulate.h>
12 #include <asm/kvm_host.h>
13 #include <asm/kvm_hyp.h>
14 #include <asm/kvm_mmu.h>
15 
16 #include <nvhe/ffa.h>
17 #include <nvhe/mem_protect.h>
18 #include <nvhe/mm.h>
19 #include <nvhe/pkvm.h>
20 #include <nvhe/trap_handler.h>
21 
22 DEFINE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
23 
24 void __kvm_hyp_host_forward_smc(struct kvm_cpu_context *host_ctxt);
25 
26 static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
27 {
28 	struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu;
29 
30 	hyp_vcpu->vcpu.arch.ctxt	= host_vcpu->arch.ctxt;
31 
32 	hyp_vcpu->vcpu.arch.sve_state	= kern_hyp_va(host_vcpu->arch.sve_state);
33 	hyp_vcpu->vcpu.arch.sve_max_vl	= host_vcpu->arch.sve_max_vl;
34 
35 	hyp_vcpu->vcpu.arch.hw_mmu	= host_vcpu->arch.hw_mmu;
36 
37 	hyp_vcpu->vcpu.arch.hcr_el2	= host_vcpu->arch.hcr_el2;
38 	hyp_vcpu->vcpu.arch.mdcr_el2	= host_vcpu->arch.mdcr_el2;
39 	hyp_vcpu->vcpu.arch.cptr_el2	= host_vcpu->arch.cptr_el2;
40 
41 	hyp_vcpu->vcpu.arch.iflags	= host_vcpu->arch.iflags;
42 	hyp_vcpu->vcpu.arch.fp_state	= host_vcpu->arch.fp_state;
43 
44 	hyp_vcpu->vcpu.arch.debug_ptr	= kern_hyp_va(host_vcpu->arch.debug_ptr);
45 	hyp_vcpu->vcpu.arch.host_fpsimd_state = host_vcpu->arch.host_fpsimd_state;
46 
47 	hyp_vcpu->vcpu.arch.vsesr_el2	= host_vcpu->arch.vsesr_el2;
48 
49 	hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3 = host_vcpu->arch.vgic_cpu.vgic_v3;
50 }
51 
52 static void sync_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
53 {
54 	struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu;
55 	struct vgic_v3_cpu_if *hyp_cpu_if = &hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3;
56 	struct vgic_v3_cpu_if *host_cpu_if = &host_vcpu->arch.vgic_cpu.vgic_v3;
57 	unsigned int i;
58 
59 	host_vcpu->arch.ctxt		= hyp_vcpu->vcpu.arch.ctxt;
60 
61 	host_vcpu->arch.hcr_el2		= hyp_vcpu->vcpu.arch.hcr_el2;
62 	host_vcpu->arch.cptr_el2	= hyp_vcpu->vcpu.arch.cptr_el2;
63 
64 	host_vcpu->arch.fault		= hyp_vcpu->vcpu.arch.fault;
65 
66 	host_vcpu->arch.iflags		= hyp_vcpu->vcpu.arch.iflags;
67 	host_vcpu->arch.fp_state	= hyp_vcpu->vcpu.arch.fp_state;
68 
69 	host_cpu_if->vgic_hcr		= hyp_cpu_if->vgic_hcr;
70 	for (i = 0; i < hyp_cpu_if->used_lrs; ++i)
71 		host_cpu_if->vgic_lr[i] = hyp_cpu_if->vgic_lr[i];
72 }
73 
74 static void handle___kvm_vcpu_run(struct kvm_cpu_context *host_ctxt)
75 {
76 	DECLARE_REG(struct kvm_vcpu *, host_vcpu, host_ctxt, 1);
77 	int ret;
78 
79 	host_vcpu = kern_hyp_va(host_vcpu);
80 
81 	if (unlikely(is_protected_kvm_enabled())) {
82 		struct pkvm_hyp_vcpu *hyp_vcpu;
83 		struct kvm *host_kvm;
84 
85 		host_kvm = kern_hyp_va(host_vcpu->kvm);
86 		hyp_vcpu = pkvm_load_hyp_vcpu(host_kvm->arch.pkvm.handle,
87 					      host_vcpu->vcpu_idx);
88 		if (!hyp_vcpu) {
89 			ret = -EINVAL;
90 			goto out;
91 		}
92 
93 		flush_hyp_vcpu(hyp_vcpu);
94 
95 		ret = __kvm_vcpu_run(&hyp_vcpu->vcpu);
96 
97 		sync_hyp_vcpu(hyp_vcpu);
98 		pkvm_put_hyp_vcpu(hyp_vcpu);
99 	} else {
100 		/* The host is fully trusted, run its vCPU directly. */
101 		ret = __kvm_vcpu_run(host_vcpu);
102 	}
103 
104 out:
105 	cpu_reg(host_ctxt, 1) =  ret;
106 }
107 
108 static void handle___kvm_adjust_pc(struct kvm_cpu_context *host_ctxt)
109 {
110 	DECLARE_REG(struct kvm_vcpu *, vcpu, host_ctxt, 1);
111 
112 	__kvm_adjust_pc(kern_hyp_va(vcpu));
113 }
114 
115 static void handle___kvm_flush_vm_context(struct kvm_cpu_context *host_ctxt)
116 {
117 	__kvm_flush_vm_context();
118 }
119 
120 static void handle___kvm_tlb_flush_vmid_ipa(struct kvm_cpu_context *host_ctxt)
121 {
122 	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
123 	DECLARE_REG(phys_addr_t, ipa, host_ctxt, 2);
124 	DECLARE_REG(int, level, host_ctxt, 3);
125 
126 	__kvm_tlb_flush_vmid_ipa(kern_hyp_va(mmu), ipa, level);
127 }
128 
129 static void handle___kvm_tlb_flush_vmid_ipa_nsh(struct kvm_cpu_context *host_ctxt)
130 {
131 	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
132 	DECLARE_REG(phys_addr_t, ipa, host_ctxt, 2);
133 	DECLARE_REG(int, level, host_ctxt, 3);
134 
135 	__kvm_tlb_flush_vmid_ipa_nsh(kern_hyp_va(mmu), ipa, level);
136 }
137 
138 static void
139 handle___kvm_tlb_flush_vmid_range(struct kvm_cpu_context *host_ctxt)
140 {
141 	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
142 	DECLARE_REG(phys_addr_t, start, host_ctxt, 2);
143 	DECLARE_REG(unsigned long, pages, host_ctxt, 3);
144 
145 	__kvm_tlb_flush_vmid_range(kern_hyp_va(mmu), start, pages);
146 }
147 
148 static void handle___kvm_tlb_flush_vmid(struct kvm_cpu_context *host_ctxt)
149 {
150 	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
151 
152 	__kvm_tlb_flush_vmid(kern_hyp_va(mmu));
153 }
154 
155 static void handle___kvm_flush_cpu_context(struct kvm_cpu_context *host_ctxt)
156 {
157 	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
158 
159 	__kvm_flush_cpu_context(kern_hyp_va(mmu));
160 }
161 
162 static void handle___kvm_timer_set_cntvoff(struct kvm_cpu_context *host_ctxt)
163 {
164 	__kvm_timer_set_cntvoff(cpu_reg(host_ctxt, 1));
165 }
166 
167 static void handle___kvm_enable_ssbs(struct kvm_cpu_context *host_ctxt)
168 {
169 	u64 tmp;
170 
171 	tmp = read_sysreg_el2(SYS_SCTLR);
172 	tmp |= SCTLR_ELx_DSSBS;
173 	write_sysreg_el2(tmp, SYS_SCTLR);
174 }
175 
176 static void handle___vgic_v3_get_gic_config(struct kvm_cpu_context *host_ctxt)
177 {
178 	cpu_reg(host_ctxt, 1) = __vgic_v3_get_gic_config();
179 }
180 
181 static void handle___vgic_v3_read_vmcr(struct kvm_cpu_context *host_ctxt)
182 {
183 	cpu_reg(host_ctxt, 1) = __vgic_v3_read_vmcr();
184 }
185 
186 static void handle___vgic_v3_write_vmcr(struct kvm_cpu_context *host_ctxt)
187 {
188 	__vgic_v3_write_vmcr(cpu_reg(host_ctxt, 1));
189 }
190 
191 static void handle___vgic_v3_init_lrs(struct kvm_cpu_context *host_ctxt)
192 {
193 	__vgic_v3_init_lrs();
194 }
195 
196 static void handle___kvm_get_mdcr_el2(struct kvm_cpu_context *host_ctxt)
197 {
198 	cpu_reg(host_ctxt, 1) = __kvm_get_mdcr_el2();
199 }
200 
201 static void handle___vgic_v3_save_aprs(struct kvm_cpu_context *host_ctxt)
202 {
203 	DECLARE_REG(struct vgic_v3_cpu_if *, cpu_if, host_ctxt, 1);
204 
205 	__vgic_v3_save_aprs(kern_hyp_va(cpu_if));
206 }
207 
208 static void handle___vgic_v3_restore_aprs(struct kvm_cpu_context *host_ctxt)
209 {
210 	DECLARE_REG(struct vgic_v3_cpu_if *, cpu_if, host_ctxt, 1);
211 
212 	__vgic_v3_restore_aprs(kern_hyp_va(cpu_if));
213 }
214 
215 static void handle___pkvm_init(struct kvm_cpu_context *host_ctxt)
216 {
217 	DECLARE_REG(phys_addr_t, phys, host_ctxt, 1);
218 	DECLARE_REG(unsigned long, size, host_ctxt, 2);
219 	DECLARE_REG(unsigned long, nr_cpus, host_ctxt, 3);
220 	DECLARE_REG(unsigned long *, per_cpu_base, host_ctxt, 4);
221 	DECLARE_REG(u32, hyp_va_bits, host_ctxt, 5);
222 
223 	/*
224 	 * __pkvm_init() will return only if an error occurred, otherwise it
225 	 * will tail-call in __pkvm_init_finalise() which will have to deal
226 	 * with the host context directly.
227 	 */
228 	cpu_reg(host_ctxt, 1) = __pkvm_init(phys, size, nr_cpus, per_cpu_base,
229 					    hyp_va_bits);
230 }
231 
232 static void handle___pkvm_cpu_set_vector(struct kvm_cpu_context *host_ctxt)
233 {
234 	DECLARE_REG(enum arm64_hyp_spectre_vector, slot, host_ctxt, 1);
235 
236 	cpu_reg(host_ctxt, 1) = pkvm_cpu_set_vector(slot);
237 }
238 
239 static void handle___pkvm_host_share_hyp(struct kvm_cpu_context *host_ctxt)
240 {
241 	DECLARE_REG(u64, pfn, host_ctxt, 1);
242 
243 	cpu_reg(host_ctxt, 1) = __pkvm_host_share_hyp(pfn);
244 }
245 
246 static void handle___pkvm_host_unshare_hyp(struct kvm_cpu_context *host_ctxt)
247 {
248 	DECLARE_REG(u64, pfn, host_ctxt, 1);
249 
250 	cpu_reg(host_ctxt, 1) = __pkvm_host_unshare_hyp(pfn);
251 }
252 
253 static void handle___pkvm_create_private_mapping(struct kvm_cpu_context *host_ctxt)
254 {
255 	DECLARE_REG(phys_addr_t, phys, host_ctxt, 1);
256 	DECLARE_REG(size_t, size, host_ctxt, 2);
257 	DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 3);
258 
259 	/*
260 	 * __pkvm_create_private_mapping() populates a pointer with the
261 	 * hypervisor start address of the allocation.
262 	 *
263 	 * However, handle___pkvm_create_private_mapping() hypercall crosses the
264 	 * EL1/EL2 boundary so the pointer would not be valid in this context.
265 	 *
266 	 * Instead pass the allocation address as the return value (or return
267 	 * ERR_PTR() on failure).
268 	 */
269 	unsigned long haddr;
270 	int err = __pkvm_create_private_mapping(phys, size, prot, &haddr);
271 
272 	if (err)
273 		haddr = (unsigned long)ERR_PTR(err);
274 
275 	cpu_reg(host_ctxt, 1) = haddr;
276 }
277 
278 static void handle___pkvm_prot_finalize(struct kvm_cpu_context *host_ctxt)
279 {
280 	cpu_reg(host_ctxt, 1) = __pkvm_prot_finalize();
281 }
282 
283 static void handle___pkvm_vcpu_init_traps(struct kvm_cpu_context *host_ctxt)
284 {
285 	DECLARE_REG(struct kvm_vcpu *, vcpu, host_ctxt, 1);
286 
287 	__pkvm_vcpu_init_traps(kern_hyp_va(vcpu));
288 }
289 
290 static void handle___pkvm_init_vm(struct kvm_cpu_context *host_ctxt)
291 {
292 	DECLARE_REG(struct kvm *, host_kvm, host_ctxt, 1);
293 	DECLARE_REG(unsigned long, vm_hva, host_ctxt, 2);
294 	DECLARE_REG(unsigned long, pgd_hva, host_ctxt, 3);
295 
296 	host_kvm = kern_hyp_va(host_kvm);
297 	cpu_reg(host_ctxt, 1) = __pkvm_init_vm(host_kvm, vm_hva, pgd_hva);
298 }
299 
300 static void handle___pkvm_init_vcpu(struct kvm_cpu_context *host_ctxt)
301 {
302 	DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
303 	DECLARE_REG(struct kvm_vcpu *, host_vcpu, host_ctxt, 2);
304 	DECLARE_REG(unsigned long, vcpu_hva, host_ctxt, 3);
305 
306 	host_vcpu = kern_hyp_va(host_vcpu);
307 	cpu_reg(host_ctxt, 1) = __pkvm_init_vcpu(handle, host_vcpu, vcpu_hva);
308 }
309 
310 static void handle___pkvm_teardown_vm(struct kvm_cpu_context *host_ctxt)
311 {
312 	DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
313 
314 	cpu_reg(host_ctxt, 1) = __pkvm_teardown_vm(handle);
315 }
316 
317 typedef void (*hcall_t)(struct kvm_cpu_context *);
318 
319 #define HANDLE_FUNC(x)	[__KVM_HOST_SMCCC_FUNC_##x] = (hcall_t)handle_##x
320 
321 static const hcall_t host_hcall[] = {
322 	/* ___kvm_hyp_init */
323 	HANDLE_FUNC(__kvm_get_mdcr_el2),
324 	HANDLE_FUNC(__pkvm_init),
325 	HANDLE_FUNC(__pkvm_create_private_mapping),
326 	HANDLE_FUNC(__pkvm_cpu_set_vector),
327 	HANDLE_FUNC(__kvm_enable_ssbs),
328 	HANDLE_FUNC(__vgic_v3_init_lrs),
329 	HANDLE_FUNC(__vgic_v3_get_gic_config),
330 	HANDLE_FUNC(__pkvm_prot_finalize),
331 
332 	HANDLE_FUNC(__pkvm_host_share_hyp),
333 	HANDLE_FUNC(__pkvm_host_unshare_hyp),
334 	HANDLE_FUNC(__kvm_adjust_pc),
335 	HANDLE_FUNC(__kvm_vcpu_run),
336 	HANDLE_FUNC(__kvm_flush_vm_context),
337 	HANDLE_FUNC(__kvm_tlb_flush_vmid_ipa),
338 	HANDLE_FUNC(__kvm_tlb_flush_vmid_ipa_nsh),
339 	HANDLE_FUNC(__kvm_tlb_flush_vmid),
340 	HANDLE_FUNC(__kvm_tlb_flush_vmid_range),
341 	HANDLE_FUNC(__kvm_flush_cpu_context),
342 	HANDLE_FUNC(__kvm_timer_set_cntvoff),
343 	HANDLE_FUNC(__vgic_v3_read_vmcr),
344 	HANDLE_FUNC(__vgic_v3_write_vmcr),
345 	HANDLE_FUNC(__vgic_v3_save_aprs),
346 	HANDLE_FUNC(__vgic_v3_restore_aprs),
347 	HANDLE_FUNC(__pkvm_vcpu_init_traps),
348 	HANDLE_FUNC(__pkvm_init_vm),
349 	HANDLE_FUNC(__pkvm_init_vcpu),
350 	HANDLE_FUNC(__pkvm_teardown_vm),
351 };
352 
353 static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)
354 {
355 	DECLARE_REG(unsigned long, id, host_ctxt, 0);
356 	unsigned long hcall_min = 0;
357 	hcall_t hfn;
358 
359 	/*
360 	 * If pKVM has been initialised then reject any calls to the
361 	 * early "privileged" hypercalls. Note that we cannot reject
362 	 * calls to __pkvm_prot_finalize for two reasons: (1) The static
363 	 * key used to determine initialisation must be toggled prior to
364 	 * finalisation and (2) finalisation is performed on a per-CPU
365 	 * basis. This is all fine, however, since __pkvm_prot_finalize
366 	 * returns -EPERM after the first call for a given CPU.
367 	 */
368 	if (static_branch_unlikely(&kvm_protected_mode_initialized))
369 		hcall_min = __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize;
370 
371 	id &= ~ARM_SMCCC_CALL_HINTS;
372 	id -= KVM_HOST_SMCCC_ID(0);
373 
374 	if (unlikely(id < hcall_min || id >= ARRAY_SIZE(host_hcall)))
375 		goto inval;
376 
377 	hfn = host_hcall[id];
378 	if (unlikely(!hfn))
379 		goto inval;
380 
381 	cpu_reg(host_ctxt, 0) = SMCCC_RET_SUCCESS;
382 	hfn(host_ctxt);
383 
384 	return;
385 inval:
386 	cpu_reg(host_ctxt, 0) = SMCCC_RET_NOT_SUPPORTED;
387 }
388 
389 static void default_host_smc_handler(struct kvm_cpu_context *host_ctxt)
390 {
391 	__kvm_hyp_host_forward_smc(host_ctxt);
392 }
393 
394 static void handle_host_smc(struct kvm_cpu_context *host_ctxt)
395 {
396 	DECLARE_REG(u64, func_id, host_ctxt, 0);
397 	bool handled;
398 
399 	func_id &= ~ARM_SMCCC_CALL_HINTS;
400 
401 	handled = kvm_host_psci_handler(host_ctxt, func_id);
402 	if (!handled)
403 		handled = kvm_host_ffa_handler(host_ctxt, func_id);
404 	if (!handled)
405 		default_host_smc_handler(host_ctxt);
406 
407 	/* SMC was trapped, move ELR past the current PC. */
408 	kvm_skip_host_instr();
409 }
410 
411 void handle_trap(struct kvm_cpu_context *host_ctxt)
412 {
413 	u64 esr = read_sysreg_el2(SYS_ESR);
414 
415 	switch (ESR_ELx_EC(esr)) {
416 	case ESR_ELx_EC_HVC64:
417 		handle_host_hcall(host_ctxt);
418 		break;
419 	case ESR_ELx_EC_SMC64:
420 		handle_host_smc(host_ctxt);
421 		break;
422 	case ESR_ELx_EC_SVE:
423 		if (has_hvhe())
424 			sysreg_clear_set(cpacr_el1, 0, (CPACR_EL1_ZEN_EL1EN |
425 							CPACR_EL1_ZEN_EL0EN));
426 		else
427 			sysreg_clear_set(cptr_el2, CPTR_EL2_TZ, 0);
428 		isb();
429 		sve_cond_update_zcr_vq(ZCR_ELx_LEN_MASK, SYS_ZCR_EL2);
430 		break;
431 	case ESR_ELx_EC_IABT_LOW:
432 	case ESR_ELx_EC_DABT_LOW:
433 		handle_host_mem_abort(host_ctxt);
434 		break;
435 	default:
436 		BUG();
437 	}
438 }
439