xref: /linux/arch/arm64/include/asm/kvm_asm.h (revision 83a3980750e3cc25cb7ded90f11c157eb3f9f428)
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 #include <asm/sysreg.h>
14 
15 #define ARM_EXIT_WITH_SERROR_BIT  31
16 #define ARM_EXCEPTION_CODE(x)	  ((x) & ~(1U << ARM_EXIT_WITH_SERROR_BIT))
17 #define ARM_EXCEPTION_IS_TRAP(x)  (ARM_EXCEPTION_CODE((x)) == ARM_EXCEPTION_TRAP)
18 #define ARM_SERROR_PENDING(x)	  !!((x) & (1U << ARM_EXIT_WITH_SERROR_BIT))
19 
20 #define ARM_EXCEPTION_IRQ	  0
21 #define ARM_EXCEPTION_EL1_SERROR  1
22 #define ARM_EXCEPTION_TRAP	  2
23 #define ARM_EXCEPTION_IL	  3
24 /* The hyp-stub will return this for any kvm_call_hyp() call */
25 #define ARM_EXCEPTION_HYP_GONE	  HVC_STUB_ERR
26 
27 #define kvm_arm_exception_type					\
28 	{ARM_EXCEPTION_IRQ,		"IRQ"		},	\
29 	{ARM_EXCEPTION_EL1_SERROR, 	"SERROR"	},	\
30 	{ARM_EXCEPTION_TRAP, 		"TRAP"		},	\
31 	{ARM_EXCEPTION_HYP_GONE,	"HYP_GONE"	}
32 
33 /*
34  * Size of the HYP vectors preamble. kvm_patch_vector_branch() generates code
35  * that jumps over this.
36  */
37 #define KVM_VECTOR_PREAMBLE	(2 * AARCH64_INSN_SIZE)
38 
39 #define KVM_HOST_SMCCC_ID(id)						\
40 	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\
41 			   ARM_SMCCC_SMC_64,				\
42 			   ARM_SMCCC_OWNER_VENDOR_HYP,			\
43 			   (id))
44 
45 #define KVM_HOST_SMCCC_FUNC(name) KVM_HOST_SMCCC_ID(__KVM_HOST_SMCCC_FUNC_##name)
46 
47 #define __KVM_HOST_SMCCC_FUNC___kvm_hyp_init			0
48 
49 #ifndef __ASSEMBLER__
50 
51 #include <linux/mm.h>
52 
53 enum __kvm_host_smccc_func {
54 	/* Hypercalls that are unavailable once pKVM has finalised. */
55 	/* __KVM_HOST_SMCCC_FUNC___kvm_hyp_init */
56 	__KVM_HOST_SMCCC_FUNC___pkvm_init = __KVM_HOST_SMCCC_FUNC___kvm_hyp_init + 1,
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 	__KVM_HOST_SMCCC_FUNC_MIN_PKVM = __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize,
64 
65 	/* Hypercalls that are always available and common to [nh]VHE/pKVM. */
66 	__KVM_HOST_SMCCC_FUNC___kvm_adjust_pc,
67 	__KVM_HOST_SMCCC_FUNC___kvm_vcpu_run,
68 	__KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context,
69 	__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa,
70 	__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa_nsh,
71 	__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid,
72 	__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_range,
73 	__KVM_HOST_SMCCC_FUNC___kvm_flush_cpu_context,
74 	__KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff,
75 	__KVM_HOST_SMCCC_FUNC___vgic_v3_save_aprs,
76 	__KVM_HOST_SMCCC_FUNC___vgic_v3_restore_vmcr_aprs,
77 	__KVM_HOST_SMCCC_FUNC___vgic_v5_save_apr,
78 	__KVM_HOST_SMCCC_FUNC___vgic_v5_restore_vmcr_apr,
79 	__KVM_HOST_SMCCC_FUNC_MAX_NO_PKVM = __KVM_HOST_SMCCC_FUNC___vgic_v5_restore_vmcr_apr,
80 
81 	/* Hypercalls that are available only when pKVM has finalised. */
82 	__KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp,
83 	__KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp,
84 	__KVM_HOST_SMCCC_FUNC___pkvm_host_donate_guest,
85 	__KVM_HOST_SMCCC_FUNC___pkvm_host_share_guest,
86 	__KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_guest,
87 	__KVM_HOST_SMCCC_FUNC___pkvm_host_relax_perms_guest,
88 	__KVM_HOST_SMCCC_FUNC___pkvm_host_wrprotect_guest,
89 	__KVM_HOST_SMCCC_FUNC___pkvm_host_test_clear_young_guest,
90 	__KVM_HOST_SMCCC_FUNC___pkvm_host_mkyoung_guest,
91 	__KVM_HOST_SMCCC_FUNC___pkvm_reserve_vm,
92 	__KVM_HOST_SMCCC_FUNC___pkvm_unreserve_vm,
93 	__KVM_HOST_SMCCC_FUNC___pkvm_init_vm,
94 	__KVM_HOST_SMCCC_FUNC___pkvm_init_vcpu,
95 	__KVM_HOST_SMCCC_FUNC___pkvm_vcpu_in_poison_fault,
96 	__KVM_HOST_SMCCC_FUNC___pkvm_force_reclaim_guest_page,
97 	__KVM_HOST_SMCCC_FUNC___pkvm_reclaim_dying_guest_page,
98 	__KVM_HOST_SMCCC_FUNC___pkvm_start_teardown_vm,
99 	__KVM_HOST_SMCCC_FUNC___pkvm_finalize_teardown_vm,
100 	__KVM_HOST_SMCCC_FUNC___pkvm_vcpu_load,
101 	__KVM_HOST_SMCCC_FUNC___pkvm_vcpu_put,
102 	__KVM_HOST_SMCCC_FUNC___pkvm_tlb_flush_vmid,
103 	__KVM_HOST_SMCCC_FUNC___tracing_load,
104 	__KVM_HOST_SMCCC_FUNC___tracing_unload,
105 	__KVM_HOST_SMCCC_FUNC___tracing_enable,
106 	__KVM_HOST_SMCCC_FUNC___tracing_swap_reader,
107 	__KVM_HOST_SMCCC_FUNC___tracing_update_clock,
108 	__KVM_HOST_SMCCC_FUNC___tracing_reset,
109 	__KVM_HOST_SMCCC_FUNC___tracing_enable_event,
110 	__KVM_HOST_SMCCC_FUNC___tracing_write_event,
111 };
112 
113 #define DECLARE_KVM_VHE_SYM(sym)	extern char sym[]
114 #define DECLARE_KVM_NVHE_SYM(sym)	extern char kvm_nvhe_sym(sym)[]
115 
116 /*
117  * Define a pair of symbols sharing the same name but one defined in
118  * VHE and the other in nVHE hyp implementations.
119  */
120 #define DECLARE_KVM_HYP_SYM(sym)		\
121 	DECLARE_KVM_VHE_SYM(sym);		\
122 	DECLARE_KVM_NVHE_SYM(sym)
123 
124 #define DECLARE_KVM_VHE_PER_CPU(type, sym)	\
125 	DECLARE_PER_CPU(type, sym)
126 #define DECLARE_KVM_NVHE_PER_CPU(type, sym)	\
127 	DECLARE_PER_CPU(type, kvm_nvhe_sym(sym))
128 
129 #define DECLARE_KVM_HYP_PER_CPU(type, sym)	\
130 	DECLARE_KVM_VHE_PER_CPU(type, sym);	\
131 	DECLARE_KVM_NVHE_PER_CPU(type, sym)
132 
133 /*
134  * Compute pointer to a symbol defined in nVHE percpu region.
135  * Returns NULL if percpu memory has not been allocated yet.
136  */
137 #define this_cpu_ptr_nvhe_sym(sym)	per_cpu_ptr_nvhe_sym(sym, smp_processor_id())
138 #define per_cpu_ptr_nvhe_sym(sym, cpu)						\
139 	({									\
140 		unsigned long base, off;					\
141 		base = kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu];		\
142 		off = (unsigned long)&CHOOSE_NVHE_SYM(sym) -			\
143 		      (unsigned long)&CHOOSE_NVHE_SYM(__per_cpu_start);		\
144 		base ? (typeof(CHOOSE_NVHE_SYM(sym))*)(base + off) : NULL;	\
145 	})
146 
147 #if defined(__KVM_NVHE_HYPERVISOR__)
148 
149 #define CHOOSE_NVHE_SYM(sym)	sym
150 #define CHOOSE_HYP_SYM(sym)	CHOOSE_NVHE_SYM(sym)
151 
152 /* The nVHE hypervisor shouldn't even try to access VHE symbols */
153 extern void *__nvhe_undefined_symbol;
154 #define CHOOSE_VHE_SYM(sym)		__nvhe_undefined_symbol
155 #define this_cpu_ptr_hyp_sym(sym)	(&__nvhe_undefined_symbol)
156 #define per_cpu_ptr_hyp_sym(sym, cpu)	(&__nvhe_undefined_symbol)
157 
158 #elif defined(__KVM_VHE_HYPERVISOR__)
159 
160 #define CHOOSE_VHE_SYM(sym)	sym
161 #define CHOOSE_HYP_SYM(sym)	CHOOSE_VHE_SYM(sym)
162 
163 /* The VHE hypervisor shouldn't even try to access nVHE symbols */
164 extern void *__vhe_undefined_symbol;
165 #define CHOOSE_NVHE_SYM(sym)		__vhe_undefined_symbol
166 #define this_cpu_ptr_hyp_sym(sym)	(&__vhe_undefined_symbol)
167 #define per_cpu_ptr_hyp_sym(sym, cpu)	(&__vhe_undefined_symbol)
168 
169 #else
170 
171 /*
172  * BIG FAT WARNINGS:
173  *
174  * - Don't be tempted to change the following is_kernel_in_hyp_mode()
175  *   to has_vhe(). has_vhe() is implemented as a *final* capability,
176  *   while this is used early at boot time, when the capabilities are
177  *   not final yet....
178  *
179  * - Don't let the nVHE hypervisor have access to this, as it will
180  *   pick the *wrong* symbol (yes, it runs at EL2...).
181  */
182 #define CHOOSE_HYP_SYM(sym)		(is_kernel_in_hyp_mode()	\
183 					   ? CHOOSE_VHE_SYM(sym)	\
184 					   : CHOOSE_NVHE_SYM(sym))
185 
186 #define this_cpu_ptr_hyp_sym(sym)	(is_kernel_in_hyp_mode()	\
187 					   ? this_cpu_ptr(&sym)		\
188 					   : this_cpu_ptr_nvhe_sym(sym))
189 
190 #define per_cpu_ptr_hyp_sym(sym, cpu)	(is_kernel_in_hyp_mode()	\
191 					   ? per_cpu_ptr(&sym, cpu)	\
192 					   : per_cpu_ptr_nvhe_sym(sym, cpu))
193 
194 #define CHOOSE_VHE_SYM(sym)	sym
195 #define CHOOSE_NVHE_SYM(sym)	kvm_nvhe_sym(sym)
196 
197 #endif
198 
199 struct kvm_nvhe_init_params {
200 	unsigned long mair_el2;
201 	unsigned long tcr_el2;
202 	unsigned long tpidr_el2;
203 	unsigned long stack_hyp_va;
204 	unsigned long stack_pa;
205 	phys_addr_t pgd_pa;
206 	unsigned long hcr_el2;
207 	unsigned long vttbr;
208 	unsigned long vtcr;
209 	unsigned long tmp;
210 };
211 
212 /*
213  * Used by the host in EL1 to dump the nVHE hypervisor backtrace on
214  * hyp_panic() in non-protected mode.
215  *
216  * @stack_base:                 hyp VA of the hyp_stack base.
217  * @overflow_stack_base:        hyp VA of the hyp_overflow_stack base.
218  * @fp:                         hyp FP where the backtrace begins.
219  * @pc:                         hyp PC where the backtrace begins.
220  */
221 struct kvm_nvhe_stacktrace_info {
222 	unsigned long stack_base;
223 	unsigned long overflow_stack_base;
224 	unsigned long fp;
225 	unsigned long pc;
226 };
227 
228 /* Translate a kernel address @ptr into its equivalent linear mapping */
229 #define kvm_ksym_ref(ptr)						\
230 	({								\
231 		void *val = (ptr);					\
232 		if (!is_kernel_in_hyp_mode())				\
233 			val = lm_alias((ptr));				\
234 		val;							\
235 	 })
236 #define kvm_ksym_ref_nvhe(sym)	kvm_ksym_ref(kvm_nvhe_sym(sym))
237 
238 struct kvm;
239 struct kvm_vcpu;
240 struct kvm_s2_mmu;
241 
242 DECLARE_KVM_NVHE_SYM(__kvm_hyp_init);
243 DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
244 #define __kvm_hyp_init		CHOOSE_NVHE_SYM(__kvm_hyp_init)
245 #define __kvm_hyp_vector	CHOOSE_HYP_SYM(__kvm_hyp_vector)
246 
247 extern unsigned long kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[];
248 DECLARE_KVM_NVHE_SYM(__per_cpu_start);
249 DECLARE_KVM_NVHE_SYM(__per_cpu_end);
250 
251 DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs);
252 #define __bp_harden_hyp_vecs	CHOOSE_HYP_SYM(__bp_harden_hyp_vecs)
253 
254 extern void __kvm_flush_vm_context(void);
255 extern void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu);
256 extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa,
257 				     int level);
258 extern void __kvm_tlb_flush_vmid_ipa_nsh(struct kvm_s2_mmu *mmu,
259 					 phys_addr_t ipa,
260 					 int level);
261 extern void __kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
262 					phys_addr_t start, unsigned long pages);
263 extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
264 
265 extern int __kvm_tlbi_s1e2(struct kvm_s2_mmu *mmu, u64 va, u64 sys_encoding);
266 
267 extern void __kvm_timer_set_cntvoff(u64 cntvoff);
268 extern int __kvm_at_s1e01(struct kvm_vcpu *vcpu, u32 op, u64 vaddr);
269 extern int __kvm_at_s1e2(struct kvm_vcpu *vcpu, u32 op, u64 vaddr);
270 extern int __kvm_at_s12(struct kvm_vcpu *vcpu, u32 op, u64 vaddr);
271 
272 extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
273 
274 extern void __kvm_adjust_pc(struct kvm_vcpu *vcpu);
275 
276 extern u64 __vgic_v3_get_gic_config(void);
277 extern void __vgic_v3_init_lrs(void);
278 
279 #define __KVM_EXTABLE(from, to)						\
280 	"	.pushsection	__kvm_ex_table, \"a\"\n"		\
281 	"	.align		3\n"					\
282 	"	.long		(" #from " - .), (" #to " - .)\n"	\
283 	"	.popsection\n"
284 
285 
286 #define __kvm_at(at_op, addr)						\
287 ( { 									\
288 	int __kvm_at_err = 0;						\
289 	u64 spsr, elr;							\
290 	asm volatile(							\
291 	"	mrs	%1, spsr_el2\n"					\
292 	"	mrs	%2, elr_el2\n"					\
293 	"1:	" __msr_s(at_op, "%3") "\n"				\
294 	"	isb\n"							\
295 	"	b	9f\n"						\
296 	"2:	msr	spsr_el2, %1\n"					\
297 	"	msr	elr_el2, %2\n"					\
298 	"	mov	%w0, %4\n"					\
299 	"9:\n"								\
300 	__KVM_EXTABLE(1b, 2b)						\
301 	: "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr)		\
302 	: "r" (addr), "i" (-EFAULT));					\
303 	__kvm_at_err;							\
304 } )
305 
306 void __noreturn hyp_panic(void);
307 asmlinkage void kvm_unexpected_el2_exception(void);
308 asmlinkage void __noreturn hyp_panic(void);
309 asmlinkage void __noreturn hyp_panic_bad_stack(void);
310 asmlinkage void kvm_unexpected_el2_exception(void);
311 struct kvm_cpu_context;
312 void handle_trap(struct kvm_cpu_context *host_ctxt);
313 asmlinkage void __noreturn __kvm_host_psci_cpu_on_entry(void);
314 asmlinkage void __noreturn __kvm_host_psci_cpu_resume_entry(void);
315 void __noreturn __pkvm_init_finalise(void);
316 void kvm_nvhe_prepare_backtrace(unsigned long fp, unsigned long pc);
317 void kvm_patch_vector_branch(struct alt_instr *alt,
318 	__le32 *origptr, __le32 *updptr, int nr_inst);
319 void kvm_get_kimage_voffset(struct alt_instr *alt,
320 	__le32 *origptr, __le32 *updptr, int nr_inst);
321 void kvm_compute_final_ctr_el0(struct alt_instr *alt,
322 	__le32 *origptr, __le32 *updptr, int nr_inst);
323 void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr, u64 elr_virt,
324 	u64 elr_phys, u64 par, uintptr_t vcpu, u64 far, u64 hpfar);
325 
326 #else /* __ASSEMBLER__ */
327 
328 .macro get_host_ctxt reg, tmp
329 	adr_this_cpu \reg, kvm_host_data, \tmp
330 	add	\reg, \reg, #HOST_DATA_CONTEXT
331 .endm
332 
333 .macro get_vcpu_ptr vcpu, ctxt
334 	get_host_ctxt \ctxt, \vcpu
335 	ldr	\vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
336 .endm
337 
338 .macro get_loaded_vcpu vcpu, ctxt
339 	adr_this_cpu \ctxt, kvm_hyp_ctxt, \vcpu
340 	ldr	\vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
341 .endm
342 
343 .macro set_loaded_vcpu vcpu, ctxt, tmp
344 	adr_this_cpu \ctxt, kvm_hyp_ctxt, \tmp
345 	str	\vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
346 .endm
347 
348 /*
349  * KVM extable for unexpected exceptions.
350  * Create a struct kvm_exception_table_entry output to a section that can be
351  * mapped by EL2. The table is not sorted.
352  *
353  * The caller must ensure:
354  * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
355  * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
356  */
357 .macro	_kvm_extable, from, to
358 	.pushsection	__kvm_ex_table, "a"
359 	.align		3
360 	.long		(\from - .), (\to - .)
361 	.popsection
362 .endm
363 
364 #define CPU_XREG_OFFSET(x)	(CPU_USER_PT_REGS + 8*x)
365 #define CPU_LR_OFFSET		CPU_XREG_OFFSET(30)
366 #define CPU_SP_EL0_OFFSET	(CPU_LR_OFFSET + 8)
367 
368 /*
369  * We treat x18 as callee-saved as the host may use it as a platform
370  * register (e.g. for shadow call stack).
371  */
372 .macro save_callee_saved_regs ctxt
373 	str	x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
374 	stp	x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
375 	stp	x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
376 	stp	x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
377 	stp	x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
378 	stp	x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
379 	stp	x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
380 .endm
381 
382 .macro restore_callee_saved_regs ctxt
383 	// We require \ctxt is not x18-x28
384 	ldr	x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
385 	ldp	x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
386 	ldp	x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
387 	ldp	x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
388 	ldp	x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
389 	ldp	x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
390 	ldp	x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
391 .endm
392 
393 .macro save_sp_el0 ctxt, tmp
394 	mrs	\tmp,	sp_el0
395 	str	\tmp,	[\ctxt, #CPU_SP_EL0_OFFSET]
396 .endm
397 
398 .macro restore_sp_el0 ctxt, tmp
399 	ldr	\tmp,	  [\ctxt, #CPU_SP_EL0_OFFSET]
400 	msr	sp_el0, \tmp
401 .endm
402 
403 #endif
404 
405 #endif /* __ARM_KVM_ASM_H__ */
406