1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (C) 2012,2013 - ARM Ltd
4 * Author: Marc Zyngier <marc.zyngier@arm.com>
5 */
6
7 #ifndef __ARM_KVM_ASM_H__
8 #define __ARM_KVM_ASM_H__
9
10 #include <asm/hyp_image.h>
11 #include <asm/insn.h>
12 #include <asm/virt.h>
13
14 #define ARM_EXIT_WITH_SERROR_BIT 31
15 #define ARM_EXCEPTION_CODE(x) ((x) & ~(1U << ARM_EXIT_WITH_SERROR_BIT))
16 #define ARM_EXCEPTION_IS_TRAP(x) (ARM_EXCEPTION_CODE((x)) == ARM_EXCEPTION_TRAP)
17 #define ARM_SERROR_PENDING(x) !!((x) & (1U << ARM_EXIT_WITH_SERROR_BIT))
18
19 #define ARM_EXCEPTION_IRQ 0
20 #define ARM_EXCEPTION_EL1_SERROR 1
21 #define ARM_EXCEPTION_TRAP 2
22 #define ARM_EXCEPTION_IL 3
23 /* The hyp-stub will return this for any kvm_call_hyp() call */
24 #define ARM_EXCEPTION_HYP_GONE HVC_STUB_ERR
25
26 #define kvm_arm_exception_type \
27 {ARM_EXCEPTION_IRQ, "IRQ" }, \
28 {ARM_EXCEPTION_EL1_SERROR, "SERROR" }, \
29 {ARM_EXCEPTION_TRAP, "TRAP" }, \
30 {ARM_EXCEPTION_HYP_GONE, "HYP_GONE" }
31
32 /*
33 * Size of the HYP vectors preamble. kvm_patch_vector_branch() generates code
34 * that jumps over this.
35 */
36 #define KVM_VECTOR_PREAMBLE (2 * AARCH64_INSN_SIZE)
37
38 #define KVM_HOST_SMCCC_ID(id) \
39 ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
40 ARM_SMCCC_SMC_64, \
41 ARM_SMCCC_OWNER_VENDOR_HYP, \
42 (id))
43
44 #define KVM_HOST_SMCCC_FUNC(name) KVM_HOST_SMCCC_ID(__KVM_HOST_SMCCC_FUNC_##name)
45
46 #define __KVM_HOST_SMCCC_FUNC___kvm_hyp_init 0
47
48 #ifndef __ASSEMBLY__
49
50 #include <linux/mm.h>
51
52 enum __kvm_host_smccc_func {
53 /* Hypercalls available only prior to pKVM finalisation */
54 /* __KVM_HOST_SMCCC_FUNC___kvm_hyp_init */
55 __KVM_HOST_SMCCC_FUNC___kvm_get_mdcr_el2 = __KVM_HOST_SMCCC_FUNC___kvm_hyp_init + 1,
56 __KVM_HOST_SMCCC_FUNC___pkvm_init,
57 __KVM_HOST_SMCCC_FUNC___pkvm_create_private_mapping,
58 __KVM_HOST_SMCCC_FUNC___pkvm_cpu_set_vector,
59 __KVM_HOST_SMCCC_FUNC___kvm_enable_ssbs,
60 __KVM_HOST_SMCCC_FUNC___vgic_v3_init_lrs,
61 __KVM_HOST_SMCCC_FUNC___vgic_v3_get_gic_config,
62 __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize,
63
64 /* Hypercalls available after pKVM finalisation */
65 __KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp,
66 __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp,
67 __KVM_HOST_SMCCC_FUNC___kvm_adjust_pc,
68 __KVM_HOST_SMCCC_FUNC___kvm_vcpu_run,
69 __KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context,
70 __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa,
71 __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa_nsh,
72 __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid,
73 __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_range,
74 __KVM_HOST_SMCCC_FUNC___kvm_flush_cpu_context,
75 __KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff,
76 __KVM_HOST_SMCCC_FUNC___vgic_v3_save_vmcr_aprs,
77 __KVM_HOST_SMCCC_FUNC___vgic_v3_restore_vmcr_aprs,
78 __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_init_traps,
79 __KVM_HOST_SMCCC_FUNC___pkvm_init_vm,
80 __KVM_HOST_SMCCC_FUNC___pkvm_init_vcpu,
81 __KVM_HOST_SMCCC_FUNC___pkvm_teardown_vm,
82 };
83
84 #define DECLARE_KVM_VHE_SYM(sym) extern char sym[]
85 #define DECLARE_KVM_NVHE_SYM(sym) extern char kvm_nvhe_sym(sym)[]
86
87 /*
88 * Define a pair of symbols sharing the same name but one defined in
89 * VHE and the other in nVHE hyp implementations.
90 */
91 #define DECLARE_KVM_HYP_SYM(sym) \
92 DECLARE_KVM_VHE_SYM(sym); \
93 DECLARE_KVM_NVHE_SYM(sym)
94
95 #define DECLARE_KVM_VHE_PER_CPU(type, sym) \
96 DECLARE_PER_CPU(type, sym)
97 #define DECLARE_KVM_NVHE_PER_CPU(type, sym) \
98 DECLARE_PER_CPU(type, kvm_nvhe_sym(sym))
99
100 #define DECLARE_KVM_HYP_PER_CPU(type, sym) \
101 DECLARE_KVM_VHE_PER_CPU(type, sym); \
102 DECLARE_KVM_NVHE_PER_CPU(type, sym)
103
104 /*
105 * Compute pointer to a symbol defined in nVHE percpu region.
106 * Returns NULL if percpu memory has not been allocated yet.
107 */
108 #define this_cpu_ptr_nvhe_sym(sym) per_cpu_ptr_nvhe_sym(sym, smp_processor_id())
109 #define per_cpu_ptr_nvhe_sym(sym, cpu) \
110 ({ \
111 unsigned long base, off; \
112 base = kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu]; \
113 off = (unsigned long)&CHOOSE_NVHE_SYM(sym) - \
114 (unsigned long)&CHOOSE_NVHE_SYM(__per_cpu_start); \
115 base ? (typeof(CHOOSE_NVHE_SYM(sym))*)(base + off) : NULL; \
116 })
117
118 #if defined(__KVM_NVHE_HYPERVISOR__)
119
120 #define CHOOSE_NVHE_SYM(sym) sym
121 #define CHOOSE_HYP_SYM(sym) CHOOSE_NVHE_SYM(sym)
122
123 /* The nVHE hypervisor shouldn't even try to access VHE symbols */
124 extern void *__nvhe_undefined_symbol;
125 #define CHOOSE_VHE_SYM(sym) __nvhe_undefined_symbol
126 #define this_cpu_ptr_hyp_sym(sym) (&__nvhe_undefined_symbol)
127 #define per_cpu_ptr_hyp_sym(sym, cpu) (&__nvhe_undefined_symbol)
128
129 #elif defined(__KVM_VHE_HYPERVISOR__)
130
131 #define CHOOSE_VHE_SYM(sym) sym
132 #define CHOOSE_HYP_SYM(sym) CHOOSE_VHE_SYM(sym)
133
134 /* The VHE hypervisor shouldn't even try to access nVHE symbols */
135 extern void *__vhe_undefined_symbol;
136 #define CHOOSE_NVHE_SYM(sym) __vhe_undefined_symbol
137 #define this_cpu_ptr_hyp_sym(sym) (&__vhe_undefined_symbol)
138 #define per_cpu_ptr_hyp_sym(sym, cpu) (&__vhe_undefined_symbol)
139
140 #else
141
142 /*
143 * BIG FAT WARNINGS:
144 *
145 * - Don't be tempted to change the following is_kernel_in_hyp_mode()
146 * to has_vhe(). has_vhe() is implemented as a *final* capability,
147 * while this is used early at boot time, when the capabilities are
148 * not final yet....
149 *
150 * - Don't let the nVHE hypervisor have access to this, as it will
151 * pick the *wrong* symbol (yes, it runs at EL2...).
152 */
153 #define CHOOSE_HYP_SYM(sym) (is_kernel_in_hyp_mode() \
154 ? CHOOSE_VHE_SYM(sym) \
155 : CHOOSE_NVHE_SYM(sym))
156
157 #define this_cpu_ptr_hyp_sym(sym) (is_kernel_in_hyp_mode() \
158 ? this_cpu_ptr(&sym) \
159 : this_cpu_ptr_nvhe_sym(sym))
160
161 #define per_cpu_ptr_hyp_sym(sym, cpu) (is_kernel_in_hyp_mode() \
162 ? per_cpu_ptr(&sym, cpu) \
163 : per_cpu_ptr_nvhe_sym(sym, cpu))
164
165 #define CHOOSE_VHE_SYM(sym) sym
166 #define CHOOSE_NVHE_SYM(sym) kvm_nvhe_sym(sym)
167
168 #endif
169
170 struct kvm_nvhe_init_params {
171 unsigned long mair_el2;
172 unsigned long tcr_el2;
173 unsigned long tpidr_el2;
174 unsigned long stack_hyp_va;
175 unsigned long stack_pa;
176 phys_addr_t pgd_pa;
177 unsigned long hcr_el2;
178 unsigned long vttbr;
179 unsigned long vtcr;
180 };
181
182 /*
183 * Used by the host in EL1 to dump the nVHE hypervisor backtrace on
184 * hyp_panic() in non-protected mode.
185 *
186 * @stack_base: hyp VA of the hyp_stack base.
187 * @overflow_stack_base: hyp VA of the hyp_overflow_stack base.
188 * @fp: hyp FP where the backtrace begins.
189 * @pc: hyp PC where the backtrace begins.
190 */
191 struct kvm_nvhe_stacktrace_info {
192 unsigned long stack_base;
193 unsigned long overflow_stack_base;
194 unsigned long fp;
195 unsigned long pc;
196 };
197
198 /* Translate a kernel address @ptr into its equivalent linear mapping */
199 #define kvm_ksym_ref(ptr) \
200 ({ \
201 void *val = (ptr); \
202 if (!is_kernel_in_hyp_mode()) \
203 val = lm_alias((ptr)); \
204 val; \
205 })
206 #define kvm_ksym_ref_nvhe(sym) kvm_ksym_ref(kvm_nvhe_sym(sym))
207
208 struct kvm;
209 struct kvm_vcpu;
210 struct kvm_s2_mmu;
211
212 DECLARE_KVM_NVHE_SYM(__kvm_hyp_init);
213 DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
214 #define __kvm_hyp_init CHOOSE_NVHE_SYM(__kvm_hyp_init)
215 #define __kvm_hyp_vector CHOOSE_HYP_SYM(__kvm_hyp_vector)
216
217 extern unsigned long kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[];
218 DECLARE_KVM_NVHE_SYM(__per_cpu_start);
219 DECLARE_KVM_NVHE_SYM(__per_cpu_end);
220
221 DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs);
222 #define __bp_harden_hyp_vecs CHOOSE_HYP_SYM(__bp_harden_hyp_vecs)
223
224 extern void __kvm_flush_vm_context(void);
225 extern void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu);
226 extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa,
227 int level);
228 extern void __kvm_tlb_flush_vmid_ipa_nsh(struct kvm_s2_mmu *mmu,
229 phys_addr_t ipa,
230 int level);
231 extern void __kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
232 phys_addr_t start, unsigned long pages);
233 extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
234
235 extern int __kvm_tlbi_s1e2(struct kvm_s2_mmu *mmu, u64 va, u64 sys_encoding);
236
237 extern void __kvm_timer_set_cntvoff(u64 cntvoff);
238
239 extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
240
241 extern void __kvm_adjust_pc(struct kvm_vcpu *vcpu);
242
243 extern u64 __vgic_v3_get_gic_config(void);
244 extern void __vgic_v3_init_lrs(void);
245
246 extern u64 __kvm_get_mdcr_el2(void);
247
248 #define __KVM_EXTABLE(from, to) \
249 " .pushsection __kvm_ex_table, \"a\"\n" \
250 " .align 3\n" \
251 " .long (" #from " - .), (" #to " - .)\n" \
252 " .popsection\n"
253
254
255 #define __kvm_at(at_op, addr) \
256 ( { \
257 int __kvm_at_err = 0; \
258 u64 spsr, elr; \
259 asm volatile( \
260 " mrs %1, spsr_el2\n" \
261 " mrs %2, elr_el2\n" \
262 "1: at "at_op", %3\n" \
263 " isb\n" \
264 " b 9f\n" \
265 "2: msr spsr_el2, %1\n" \
266 " msr elr_el2, %2\n" \
267 " mov %w0, %4\n" \
268 "9:\n" \
269 __KVM_EXTABLE(1b, 2b) \
270 : "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr) \
271 : "r" (addr), "i" (-EFAULT)); \
272 __kvm_at_err; \
273 } )
274
275 void __noreturn hyp_panic(void);
276 asmlinkage void kvm_unexpected_el2_exception(void);
277 asmlinkage void __noreturn hyp_panic(void);
278 asmlinkage void __noreturn hyp_panic_bad_stack(void);
279 asmlinkage void kvm_unexpected_el2_exception(void);
280 struct kvm_cpu_context;
281 void handle_trap(struct kvm_cpu_context *host_ctxt);
282 asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on);
283 void __noreturn __pkvm_init_finalise(void);
284 void kvm_nvhe_prepare_backtrace(unsigned long fp, unsigned long pc);
285 void kvm_patch_vector_branch(struct alt_instr *alt,
286 __le32 *origptr, __le32 *updptr, int nr_inst);
287 void kvm_get_kimage_voffset(struct alt_instr *alt,
288 __le32 *origptr, __le32 *updptr, int nr_inst);
289 void kvm_compute_final_ctr_el0(struct alt_instr *alt,
290 __le32 *origptr, __le32 *updptr, int nr_inst);
291 void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr, u64 elr_virt,
292 u64 elr_phys, u64 par, uintptr_t vcpu, u64 far, u64 hpfar);
293
294 #else /* __ASSEMBLY__ */
295
296 .macro get_host_ctxt reg, tmp
297 adr_this_cpu \reg, kvm_host_data, \tmp
298 add \reg, \reg, #HOST_DATA_CONTEXT
299 .endm
300
301 .macro get_vcpu_ptr vcpu, ctxt
302 get_host_ctxt \ctxt, \vcpu
303 ldr \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
304 .endm
305
306 .macro get_loaded_vcpu vcpu, ctxt
307 adr_this_cpu \ctxt, kvm_hyp_ctxt, \vcpu
308 ldr \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
309 .endm
310
311 .macro set_loaded_vcpu vcpu, ctxt, tmp
312 adr_this_cpu \ctxt, kvm_hyp_ctxt, \tmp
313 str \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
314 .endm
315
316 /*
317 * KVM extable for unexpected exceptions.
318 * Create a struct kvm_exception_table_entry output to a section that can be
319 * mapped by EL2. The table is not sorted.
320 *
321 * The caller must ensure:
322 * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
323 * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
324 */
325 .macro _kvm_extable, from, to
326 .pushsection __kvm_ex_table, "a"
327 .align 3
328 .long (\from - .), (\to - .)
329 .popsection
330 .endm
331
332 #define CPU_XREG_OFFSET(x) (CPU_USER_PT_REGS + 8*x)
333 #define CPU_LR_OFFSET CPU_XREG_OFFSET(30)
334 #define CPU_SP_EL0_OFFSET (CPU_LR_OFFSET + 8)
335
336 /*
337 * We treat x18 as callee-saved as the host may use it as a platform
338 * register (e.g. for shadow call stack).
339 */
340 .macro save_callee_saved_regs ctxt
341 str x18, [\ctxt, #CPU_XREG_OFFSET(18)]
342 stp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
343 stp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
344 stp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
345 stp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
346 stp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
347 stp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)]
348 .endm
349
350 .macro restore_callee_saved_regs ctxt
351 // We require \ctxt is not x18-x28
352 ldr x18, [\ctxt, #CPU_XREG_OFFSET(18)]
353 ldp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
354 ldp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
355 ldp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
356 ldp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
357 ldp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
358 ldp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)]
359 .endm
360
361 .macro save_sp_el0 ctxt, tmp
362 mrs \tmp, sp_el0
363 str \tmp, [\ctxt, #CPU_SP_EL0_OFFSET]
364 .endm
365
366 .macro restore_sp_el0 ctxt, tmp
367 ldr \tmp, [\ctxt, #CPU_SP_EL0_OFFSET]
368 msr sp_el0, \tmp
369 .endm
370
371 #endif
372
373 #endif /* __ARM_KVM_ASM_H__ */
374
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