xref: /linux/arch/arm64/kvm/hyp/nvhe/hyp-main.c (revision 6c1785cd75ef55a308701813330a162002ffe192)
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 
43 	hyp_vcpu->vcpu.arch.debug_ptr	= kern_hyp_va(host_vcpu->arch.debug_ptr);
44 
45 	hyp_vcpu->vcpu.arch.vsesr_el2	= host_vcpu->arch.vsesr_el2;
46 
47 	hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3 = host_vcpu->arch.vgic_cpu.vgic_v3;
48 }
49 
50 static void sync_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
51 {
52 	struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu;
53 	struct vgic_v3_cpu_if *hyp_cpu_if = &hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3;
54 	struct vgic_v3_cpu_if *host_cpu_if = &host_vcpu->arch.vgic_cpu.vgic_v3;
55 	unsigned int i;
56 
57 	host_vcpu->arch.ctxt		= hyp_vcpu->vcpu.arch.ctxt;
58 
59 	host_vcpu->arch.hcr_el2		= hyp_vcpu->vcpu.arch.hcr_el2;
60 	host_vcpu->arch.cptr_el2	= hyp_vcpu->vcpu.arch.cptr_el2;
61 
62 	host_vcpu->arch.fault		= hyp_vcpu->vcpu.arch.fault;
63 
64 	host_vcpu->arch.iflags		= hyp_vcpu->vcpu.arch.iflags;
65 
66 	host_cpu_if->vgic_hcr		= hyp_cpu_if->vgic_hcr;
67 	for (i = 0; i < hyp_cpu_if->used_lrs; ++i)
68 		host_cpu_if->vgic_lr[i] = hyp_cpu_if->vgic_lr[i];
69 }
70 
71 static void handle___kvm_vcpu_run(struct kvm_cpu_context *host_ctxt)
72 {
73 	DECLARE_REG(struct kvm_vcpu *, host_vcpu, host_ctxt, 1);
74 	int ret;
75 
76 	host_vcpu = kern_hyp_va(host_vcpu);
77 
78 	if (unlikely(is_protected_kvm_enabled())) {
79 		struct pkvm_hyp_vcpu *hyp_vcpu;
80 		struct kvm *host_kvm;
81 
82 		host_kvm = kern_hyp_va(host_vcpu->kvm);
83 		hyp_vcpu = pkvm_load_hyp_vcpu(host_kvm->arch.pkvm.handle,
84 					      host_vcpu->vcpu_idx);
85 		if (!hyp_vcpu) {
86 			ret = -EINVAL;
87 			goto out;
88 		}
89 
90 		flush_hyp_vcpu(hyp_vcpu);
91 
92 		ret = __kvm_vcpu_run(&hyp_vcpu->vcpu);
93 
94 		sync_hyp_vcpu(hyp_vcpu);
95 		pkvm_put_hyp_vcpu(hyp_vcpu);
96 	} else {
97 		/* The host is fully trusted, run its vCPU directly. */
98 		ret = __kvm_vcpu_run(host_vcpu);
99 	}
100 
101 out:
102 	cpu_reg(host_ctxt, 1) =  ret;
103 }
104 
105 static void handle___kvm_adjust_pc(struct kvm_cpu_context *host_ctxt)
106 {
107 	DECLARE_REG(struct kvm_vcpu *, vcpu, host_ctxt, 1);
108 
109 	__kvm_adjust_pc(kern_hyp_va(vcpu));
110 }
111 
112 static void handle___kvm_flush_vm_context(struct kvm_cpu_context *host_ctxt)
113 {
114 	__kvm_flush_vm_context();
115 }
116 
117 static void handle___kvm_tlb_flush_vmid_ipa(struct kvm_cpu_context *host_ctxt)
118 {
119 	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
120 	DECLARE_REG(phys_addr_t, ipa, host_ctxt, 2);
121 	DECLARE_REG(int, level, host_ctxt, 3);
122 
123 	__kvm_tlb_flush_vmid_ipa(kern_hyp_va(mmu), ipa, level);
124 }
125 
126 static void handle___kvm_tlb_flush_vmid_ipa_nsh(struct kvm_cpu_context *host_ctxt)
127 {
128 	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
129 	DECLARE_REG(phys_addr_t, ipa, host_ctxt, 2);
130 	DECLARE_REG(int, level, host_ctxt, 3);
131 
132 	__kvm_tlb_flush_vmid_ipa_nsh(kern_hyp_va(mmu), ipa, level);
133 }
134 
135 static void
136 handle___kvm_tlb_flush_vmid_range(struct kvm_cpu_context *host_ctxt)
137 {
138 	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
139 	DECLARE_REG(phys_addr_t, start, host_ctxt, 2);
140 	DECLARE_REG(unsigned long, pages, host_ctxt, 3);
141 
142 	__kvm_tlb_flush_vmid_range(kern_hyp_va(mmu), start, pages);
143 }
144 
145 static void handle___kvm_tlb_flush_vmid(struct kvm_cpu_context *host_ctxt)
146 {
147 	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
148 
149 	__kvm_tlb_flush_vmid(kern_hyp_va(mmu));
150 }
151 
152 static void handle___kvm_flush_cpu_context(struct kvm_cpu_context *host_ctxt)
153 {
154 	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
155 
156 	__kvm_flush_cpu_context(kern_hyp_va(mmu));
157 }
158 
159 static void handle___kvm_timer_set_cntvoff(struct kvm_cpu_context *host_ctxt)
160 {
161 	__kvm_timer_set_cntvoff(cpu_reg(host_ctxt, 1));
162 }
163 
164 static void handle___kvm_enable_ssbs(struct kvm_cpu_context *host_ctxt)
165 {
166 	u64 tmp;
167 
168 	tmp = read_sysreg_el2(SYS_SCTLR);
169 	tmp |= SCTLR_ELx_DSSBS;
170 	write_sysreg_el2(tmp, SYS_SCTLR);
171 }
172 
173 static void handle___vgic_v3_get_gic_config(struct kvm_cpu_context *host_ctxt)
174 {
175 	cpu_reg(host_ctxt, 1) = __vgic_v3_get_gic_config();
176 }
177 
178 static void handle___vgic_v3_init_lrs(struct kvm_cpu_context *host_ctxt)
179 {
180 	__vgic_v3_init_lrs();
181 }
182 
183 static void handle___kvm_get_mdcr_el2(struct kvm_cpu_context *host_ctxt)
184 {
185 	cpu_reg(host_ctxt, 1) = __kvm_get_mdcr_el2();
186 }
187 
188 static void handle___vgic_v3_save_vmcr_aprs(struct kvm_cpu_context *host_ctxt)
189 {
190 	DECLARE_REG(struct vgic_v3_cpu_if *, cpu_if, host_ctxt, 1);
191 
192 	__vgic_v3_save_vmcr_aprs(kern_hyp_va(cpu_if));
193 }
194 
195 static void handle___vgic_v3_restore_vmcr_aprs(struct kvm_cpu_context *host_ctxt)
196 {
197 	DECLARE_REG(struct vgic_v3_cpu_if *, cpu_if, host_ctxt, 1);
198 
199 	__vgic_v3_restore_vmcr_aprs(kern_hyp_va(cpu_if));
200 }
201 
202 static void handle___pkvm_init(struct kvm_cpu_context *host_ctxt)
203 {
204 	DECLARE_REG(phys_addr_t, phys, host_ctxt, 1);
205 	DECLARE_REG(unsigned long, size, host_ctxt, 2);
206 	DECLARE_REG(unsigned long, nr_cpus, host_ctxt, 3);
207 	DECLARE_REG(unsigned long *, per_cpu_base, host_ctxt, 4);
208 	DECLARE_REG(u32, hyp_va_bits, host_ctxt, 5);
209 
210 	/*
211 	 * __pkvm_init() will return only if an error occurred, otherwise it
212 	 * will tail-call in __pkvm_init_finalise() which will have to deal
213 	 * with the host context directly.
214 	 */
215 	cpu_reg(host_ctxt, 1) = __pkvm_init(phys, size, nr_cpus, per_cpu_base,
216 					    hyp_va_bits);
217 }
218 
219 static void handle___pkvm_cpu_set_vector(struct kvm_cpu_context *host_ctxt)
220 {
221 	DECLARE_REG(enum arm64_hyp_spectre_vector, slot, host_ctxt, 1);
222 
223 	cpu_reg(host_ctxt, 1) = pkvm_cpu_set_vector(slot);
224 }
225 
226 static void handle___pkvm_host_share_hyp(struct kvm_cpu_context *host_ctxt)
227 {
228 	DECLARE_REG(u64, pfn, host_ctxt, 1);
229 
230 	cpu_reg(host_ctxt, 1) = __pkvm_host_share_hyp(pfn);
231 }
232 
233 static void handle___pkvm_host_unshare_hyp(struct kvm_cpu_context *host_ctxt)
234 {
235 	DECLARE_REG(u64, pfn, host_ctxt, 1);
236 
237 	cpu_reg(host_ctxt, 1) = __pkvm_host_unshare_hyp(pfn);
238 }
239 
240 static void handle___pkvm_create_private_mapping(struct kvm_cpu_context *host_ctxt)
241 {
242 	DECLARE_REG(phys_addr_t, phys, host_ctxt, 1);
243 	DECLARE_REG(size_t, size, host_ctxt, 2);
244 	DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 3);
245 
246 	/*
247 	 * __pkvm_create_private_mapping() populates a pointer with the
248 	 * hypervisor start address of the allocation.
249 	 *
250 	 * However, handle___pkvm_create_private_mapping() hypercall crosses the
251 	 * EL1/EL2 boundary so the pointer would not be valid in this context.
252 	 *
253 	 * Instead pass the allocation address as the return value (or return
254 	 * ERR_PTR() on failure).
255 	 */
256 	unsigned long haddr;
257 	int err = __pkvm_create_private_mapping(phys, size, prot, &haddr);
258 
259 	if (err)
260 		haddr = (unsigned long)ERR_PTR(err);
261 
262 	cpu_reg(host_ctxt, 1) = haddr;
263 }
264 
265 static void handle___pkvm_prot_finalize(struct kvm_cpu_context *host_ctxt)
266 {
267 	cpu_reg(host_ctxt, 1) = __pkvm_prot_finalize();
268 }
269 
270 static void handle___pkvm_vcpu_init_traps(struct kvm_cpu_context *host_ctxt)
271 {
272 	DECLARE_REG(struct kvm_vcpu *, vcpu, host_ctxt, 1);
273 
274 	__pkvm_vcpu_init_traps(kern_hyp_va(vcpu));
275 }
276 
277 static void handle___pkvm_init_vm(struct kvm_cpu_context *host_ctxt)
278 {
279 	DECLARE_REG(struct kvm *, host_kvm, host_ctxt, 1);
280 	DECLARE_REG(unsigned long, vm_hva, host_ctxt, 2);
281 	DECLARE_REG(unsigned long, pgd_hva, host_ctxt, 3);
282 
283 	host_kvm = kern_hyp_va(host_kvm);
284 	cpu_reg(host_ctxt, 1) = __pkvm_init_vm(host_kvm, vm_hva, pgd_hva);
285 }
286 
287 static void handle___pkvm_init_vcpu(struct kvm_cpu_context *host_ctxt)
288 {
289 	DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
290 	DECLARE_REG(struct kvm_vcpu *, host_vcpu, host_ctxt, 2);
291 	DECLARE_REG(unsigned long, vcpu_hva, host_ctxt, 3);
292 
293 	host_vcpu = kern_hyp_va(host_vcpu);
294 	cpu_reg(host_ctxt, 1) = __pkvm_init_vcpu(handle, host_vcpu, vcpu_hva);
295 }
296 
297 static void handle___pkvm_teardown_vm(struct kvm_cpu_context *host_ctxt)
298 {
299 	DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
300 
301 	cpu_reg(host_ctxt, 1) = __pkvm_teardown_vm(handle);
302 }
303 
304 typedef void (*hcall_t)(struct kvm_cpu_context *);
305 
306 #define HANDLE_FUNC(x)	[__KVM_HOST_SMCCC_FUNC_##x] = (hcall_t)handle_##x
307 
308 static const hcall_t host_hcall[] = {
309 	/* ___kvm_hyp_init */
310 	HANDLE_FUNC(__kvm_get_mdcr_el2),
311 	HANDLE_FUNC(__pkvm_init),
312 	HANDLE_FUNC(__pkvm_create_private_mapping),
313 	HANDLE_FUNC(__pkvm_cpu_set_vector),
314 	HANDLE_FUNC(__kvm_enable_ssbs),
315 	HANDLE_FUNC(__vgic_v3_init_lrs),
316 	HANDLE_FUNC(__vgic_v3_get_gic_config),
317 	HANDLE_FUNC(__pkvm_prot_finalize),
318 
319 	HANDLE_FUNC(__pkvm_host_share_hyp),
320 	HANDLE_FUNC(__pkvm_host_unshare_hyp),
321 	HANDLE_FUNC(__kvm_adjust_pc),
322 	HANDLE_FUNC(__kvm_vcpu_run),
323 	HANDLE_FUNC(__kvm_flush_vm_context),
324 	HANDLE_FUNC(__kvm_tlb_flush_vmid_ipa),
325 	HANDLE_FUNC(__kvm_tlb_flush_vmid_ipa_nsh),
326 	HANDLE_FUNC(__kvm_tlb_flush_vmid),
327 	HANDLE_FUNC(__kvm_tlb_flush_vmid_range),
328 	HANDLE_FUNC(__kvm_flush_cpu_context),
329 	HANDLE_FUNC(__kvm_timer_set_cntvoff),
330 	HANDLE_FUNC(__vgic_v3_save_vmcr_aprs),
331 	HANDLE_FUNC(__vgic_v3_restore_vmcr_aprs),
332 	HANDLE_FUNC(__pkvm_vcpu_init_traps),
333 	HANDLE_FUNC(__pkvm_init_vm),
334 	HANDLE_FUNC(__pkvm_init_vcpu),
335 	HANDLE_FUNC(__pkvm_teardown_vm),
336 };
337 
338 static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)
339 {
340 	DECLARE_REG(unsigned long, id, host_ctxt, 0);
341 	unsigned long hcall_min = 0;
342 	hcall_t hfn;
343 
344 	/*
345 	 * If pKVM has been initialised then reject any calls to the
346 	 * early "privileged" hypercalls. Note that we cannot reject
347 	 * calls to __pkvm_prot_finalize for two reasons: (1) The static
348 	 * key used to determine initialisation must be toggled prior to
349 	 * finalisation and (2) finalisation is performed on a per-CPU
350 	 * basis. This is all fine, however, since __pkvm_prot_finalize
351 	 * returns -EPERM after the first call for a given CPU.
352 	 */
353 	if (static_branch_unlikely(&kvm_protected_mode_initialized))
354 		hcall_min = __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize;
355 
356 	id &= ~ARM_SMCCC_CALL_HINTS;
357 	id -= KVM_HOST_SMCCC_ID(0);
358 
359 	if (unlikely(id < hcall_min || id >= ARRAY_SIZE(host_hcall)))
360 		goto inval;
361 
362 	hfn = host_hcall[id];
363 	if (unlikely(!hfn))
364 		goto inval;
365 
366 	cpu_reg(host_ctxt, 0) = SMCCC_RET_SUCCESS;
367 	hfn(host_ctxt);
368 
369 	return;
370 inval:
371 	cpu_reg(host_ctxt, 0) = SMCCC_RET_NOT_SUPPORTED;
372 }
373 
374 static void default_host_smc_handler(struct kvm_cpu_context *host_ctxt)
375 {
376 	__kvm_hyp_host_forward_smc(host_ctxt);
377 }
378 
379 static void handle_host_smc(struct kvm_cpu_context *host_ctxt)
380 {
381 	DECLARE_REG(u64, func_id, host_ctxt, 0);
382 	bool handled;
383 
384 	func_id &= ~ARM_SMCCC_CALL_HINTS;
385 
386 	handled = kvm_host_psci_handler(host_ctxt, func_id);
387 	if (!handled)
388 		handled = kvm_host_ffa_handler(host_ctxt, func_id);
389 	if (!handled)
390 		default_host_smc_handler(host_ctxt);
391 
392 	/* SMC was trapped, move ELR past the current PC. */
393 	kvm_skip_host_instr();
394 }
395 
396 void handle_trap(struct kvm_cpu_context *host_ctxt)
397 {
398 	u64 esr = read_sysreg_el2(SYS_ESR);
399 
400 	switch (ESR_ELx_EC(esr)) {
401 	case ESR_ELx_EC_HVC64:
402 		handle_host_hcall(host_ctxt);
403 		break;
404 	case ESR_ELx_EC_SMC64:
405 		handle_host_smc(host_ctxt);
406 		break;
407 	case ESR_ELx_EC_SVE:
408 		if (has_hvhe())
409 			sysreg_clear_set(cpacr_el1, 0, (CPACR_EL1_ZEN_EL1EN |
410 							CPACR_EL1_ZEN_EL0EN));
411 		else
412 			sysreg_clear_set(cptr_el2, CPTR_EL2_TZ, 0);
413 		isb();
414 		sve_cond_update_zcr_vq(ZCR_ELx_LEN_MASK, SYS_ZCR_EL2);
415 		break;
416 	case ESR_ELx_EC_IABT_LOW:
417 	case ESR_ELx_EC_DABT_LOW:
418 		handle_host_mem_abort(host_ctxt);
419 		break;
420 	default:
421 		BUG();
422 	}
423 }
424