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
52enum __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_read_vmcr,
77	__KVM_HOST_SMCCC_FUNC___vgic_v3_write_vmcr,
78	__KVM_HOST_SMCCC_FUNC___vgic_v3_save_aprs,
79	__KVM_HOST_SMCCC_FUNC___vgic_v3_restore_aprs,
80	__KVM_HOST_SMCCC_FUNC___pkvm_vcpu_init_traps,
81	__KVM_HOST_SMCCC_FUNC___pkvm_init_vm,
82	__KVM_HOST_SMCCC_FUNC___pkvm_init_vcpu,
83	__KVM_HOST_SMCCC_FUNC___pkvm_teardown_vm,
84};
85
86#define DECLARE_KVM_VHE_SYM(sym)	extern char sym[]
87#define DECLARE_KVM_NVHE_SYM(sym)	extern char kvm_nvhe_sym(sym)[]
88
89/*
90 * Define a pair of symbols sharing the same name but one defined in
91 * VHE and the other in nVHE hyp implementations.
92 */
93#define DECLARE_KVM_HYP_SYM(sym)		\
94	DECLARE_KVM_VHE_SYM(sym);		\
95	DECLARE_KVM_NVHE_SYM(sym)
96
97#define DECLARE_KVM_VHE_PER_CPU(type, sym)	\
98	DECLARE_PER_CPU(type, sym)
99#define DECLARE_KVM_NVHE_PER_CPU(type, sym)	\
100	DECLARE_PER_CPU(type, kvm_nvhe_sym(sym))
101
102#define DECLARE_KVM_HYP_PER_CPU(type, sym)	\
103	DECLARE_KVM_VHE_PER_CPU(type, sym);	\
104	DECLARE_KVM_NVHE_PER_CPU(type, sym)
105
106/*
107 * Compute pointer to a symbol defined in nVHE percpu region.
108 * Returns NULL if percpu memory has not been allocated yet.
109 */
110#define this_cpu_ptr_nvhe_sym(sym)	per_cpu_ptr_nvhe_sym(sym, smp_processor_id())
111#define per_cpu_ptr_nvhe_sym(sym, cpu)						\
112	({									\
113		unsigned long base, off;					\
114		base = kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu];		\
115		off = (unsigned long)&CHOOSE_NVHE_SYM(sym) -			\
116		      (unsigned long)&CHOOSE_NVHE_SYM(__per_cpu_start);		\
117		base ? (typeof(CHOOSE_NVHE_SYM(sym))*)(base + off) : NULL;	\
118	})
119
120#if defined(__KVM_NVHE_HYPERVISOR__)
121
122#define CHOOSE_NVHE_SYM(sym)	sym
123#define CHOOSE_HYP_SYM(sym)	CHOOSE_NVHE_SYM(sym)
124
125/* The nVHE hypervisor shouldn't even try to access VHE symbols */
126extern void *__nvhe_undefined_symbol;
127#define CHOOSE_VHE_SYM(sym)		__nvhe_undefined_symbol
128#define this_cpu_ptr_hyp_sym(sym)	(&__nvhe_undefined_symbol)
129#define per_cpu_ptr_hyp_sym(sym, cpu)	(&__nvhe_undefined_symbol)
130
131#elif defined(__KVM_VHE_HYPERVISOR__)
132
133#define CHOOSE_VHE_SYM(sym)	sym
134#define CHOOSE_HYP_SYM(sym)	CHOOSE_VHE_SYM(sym)
135
136/* The VHE hypervisor shouldn't even try to access nVHE symbols */
137extern void *__vhe_undefined_symbol;
138#define CHOOSE_NVHE_SYM(sym)		__vhe_undefined_symbol
139#define this_cpu_ptr_hyp_sym(sym)	(&__vhe_undefined_symbol)
140#define per_cpu_ptr_hyp_sym(sym, cpu)	(&__vhe_undefined_symbol)
141
142#else
143
144/*
145 * BIG FAT WARNINGS:
146 *
147 * - Don't be tempted to change the following is_kernel_in_hyp_mode()
148 *   to has_vhe(). has_vhe() is implemented as a *final* capability,
149 *   while this is used early at boot time, when the capabilities are
150 *   not final yet....
151 *
152 * - Don't let the nVHE hypervisor have access to this, as it will
153 *   pick the *wrong* symbol (yes, it runs at EL2...).
154 */
155#define CHOOSE_HYP_SYM(sym)		(is_kernel_in_hyp_mode()	\
156					   ? CHOOSE_VHE_SYM(sym)	\
157					   : CHOOSE_NVHE_SYM(sym))
158
159#define this_cpu_ptr_hyp_sym(sym)	(is_kernel_in_hyp_mode()	\
160					   ? this_cpu_ptr(&sym)		\
161					   : this_cpu_ptr_nvhe_sym(sym))
162
163#define per_cpu_ptr_hyp_sym(sym, cpu)	(is_kernel_in_hyp_mode()	\
164					   ? per_cpu_ptr(&sym, cpu)	\
165					   : per_cpu_ptr_nvhe_sym(sym, cpu))
166
167#define CHOOSE_VHE_SYM(sym)	sym
168#define CHOOSE_NVHE_SYM(sym)	kvm_nvhe_sym(sym)
169
170#endif
171
172struct kvm_nvhe_init_params {
173	unsigned long mair_el2;
174	unsigned long tcr_el2;
175	unsigned long tpidr_el2;
176	unsigned long stack_hyp_va;
177	unsigned long stack_pa;
178	phys_addr_t pgd_pa;
179	unsigned long hcr_el2;
180	unsigned long vttbr;
181	unsigned long vtcr;
182};
183
184/*
185 * Used by the host in EL1 to dump the nVHE hypervisor backtrace on
186 * hyp_panic() in non-protected mode.
187 *
188 * @stack_base:                 hyp VA of the hyp_stack base.
189 * @overflow_stack_base:        hyp VA of the hyp_overflow_stack base.
190 * @fp:                         hyp FP where the backtrace begins.
191 * @pc:                         hyp PC where the backtrace begins.
192 */
193struct kvm_nvhe_stacktrace_info {
194	unsigned long stack_base;
195	unsigned long overflow_stack_base;
196	unsigned long fp;
197	unsigned long pc;
198};
199
200/* Translate a kernel address @ptr into its equivalent linear mapping */
201#define kvm_ksym_ref(ptr)						\
202	({								\
203		void *val = (ptr);					\
204		if (!is_kernel_in_hyp_mode())				\
205			val = lm_alias((ptr));				\
206		val;							\
207	 })
208#define kvm_ksym_ref_nvhe(sym)	kvm_ksym_ref(kvm_nvhe_sym(sym))
209
210struct kvm;
211struct kvm_vcpu;
212struct kvm_s2_mmu;
213
214DECLARE_KVM_NVHE_SYM(__kvm_hyp_init);
215DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
216#define __kvm_hyp_init		CHOOSE_NVHE_SYM(__kvm_hyp_init)
217#define __kvm_hyp_vector	CHOOSE_HYP_SYM(__kvm_hyp_vector)
218
219extern unsigned long kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[];
220DECLARE_KVM_NVHE_SYM(__per_cpu_start);
221DECLARE_KVM_NVHE_SYM(__per_cpu_end);
222
223DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs);
224#define __bp_harden_hyp_vecs	CHOOSE_HYP_SYM(__bp_harden_hyp_vecs)
225
226extern void __kvm_flush_vm_context(void);
227extern void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu);
228extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa,
229				     int level);
230extern void __kvm_tlb_flush_vmid_ipa_nsh(struct kvm_s2_mmu *mmu,
231					 phys_addr_t ipa,
232					 int level);
233extern void __kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
234					phys_addr_t start, unsigned long pages);
235extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
236
237extern void __kvm_timer_set_cntvoff(u64 cntvoff);
238
239extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
240
241extern void __kvm_adjust_pc(struct kvm_vcpu *vcpu);
242
243extern u64 __vgic_v3_get_gic_config(void);
244extern u64 __vgic_v3_read_vmcr(void);
245extern void __vgic_v3_write_vmcr(u32 vmcr);
246extern void __vgic_v3_init_lrs(void);
247
248extern u64 __kvm_get_mdcr_el2(void);
249
250#define __KVM_EXTABLE(from, to)						\
251	"	.pushsection	__kvm_ex_table, \"a\"\n"		\
252	"	.align		3\n"					\
253	"	.long		(" #from " - .), (" #to " - .)\n"	\
254	"	.popsection\n"
255
256
257#define __kvm_at(at_op, addr)						\
258( { 									\
259	int __kvm_at_err = 0;						\
260	u64 spsr, elr;							\
261	asm volatile(							\
262	"	mrs	%1, spsr_el2\n"					\
263	"	mrs	%2, elr_el2\n"					\
264	"1:	at	"at_op", %3\n"					\
265	"	isb\n"							\
266	"	b	9f\n"						\
267	"2:	msr	spsr_el2, %1\n"					\
268	"	msr	elr_el2, %2\n"					\
269	"	mov	%w0, %4\n"					\
270	"9:\n"								\
271	__KVM_EXTABLE(1b, 2b)						\
272	: "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr)		\
273	: "r" (addr), "i" (-EFAULT));					\
274	__kvm_at_err;							\
275} )
276
277void __noreturn hyp_panic(void);
278asmlinkage void kvm_unexpected_el2_exception(void);
279asmlinkage void __noreturn hyp_panic(void);
280asmlinkage void __noreturn hyp_panic_bad_stack(void);
281asmlinkage void kvm_unexpected_el2_exception(void);
282struct kvm_cpu_context;
283void handle_trap(struct kvm_cpu_context *host_ctxt);
284asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on);
285void __noreturn __pkvm_init_finalise(void);
286void kvm_nvhe_prepare_backtrace(unsigned long fp, unsigned long pc);
287void kvm_patch_vector_branch(struct alt_instr *alt,
288	__le32 *origptr, __le32 *updptr, int nr_inst);
289void kvm_get_kimage_voffset(struct alt_instr *alt,
290	__le32 *origptr, __le32 *updptr, int nr_inst);
291void kvm_compute_final_ctr_el0(struct alt_instr *alt,
292	__le32 *origptr, __le32 *updptr, int nr_inst);
293void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr, u64 elr_virt,
294	u64 elr_phys, u64 par, uintptr_t vcpu, u64 far, u64 hpfar);
295
296#else /* __ASSEMBLY__ */
297
298.macro get_host_ctxt reg, tmp
299	adr_this_cpu \reg, kvm_host_data, \tmp
300	add	\reg, \reg, #HOST_DATA_CONTEXT
301.endm
302
303.macro get_vcpu_ptr vcpu, ctxt
304	get_host_ctxt \ctxt, \vcpu
305	ldr	\vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
306.endm
307
308.macro get_loaded_vcpu vcpu, ctxt
309	adr_this_cpu \ctxt, kvm_hyp_ctxt, \vcpu
310	ldr	\vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
311.endm
312
313.macro set_loaded_vcpu vcpu, ctxt, tmp
314	adr_this_cpu \ctxt, kvm_hyp_ctxt, \tmp
315	str	\vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
316.endm
317
318/*
319 * KVM extable for unexpected exceptions.
320 * Create a struct kvm_exception_table_entry output to a section that can be
321 * mapped by EL2. The table is not sorted.
322 *
323 * The caller must ensure:
324 * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
325 * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
326 */
327.macro	_kvm_extable, from, to
328	.pushsection	__kvm_ex_table, "a"
329	.align		3
330	.long		(\from - .), (\to - .)
331	.popsection
332.endm
333
334#define CPU_XREG_OFFSET(x)	(CPU_USER_PT_REGS + 8*x)
335#define CPU_LR_OFFSET		CPU_XREG_OFFSET(30)
336#define CPU_SP_EL0_OFFSET	(CPU_LR_OFFSET + 8)
337
338/*
339 * We treat x18 as callee-saved as the host may use it as a platform
340 * register (e.g. for shadow call stack).
341 */
342.macro save_callee_saved_regs ctxt
343	str	x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
344	stp	x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
345	stp	x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
346	stp	x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
347	stp	x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
348	stp	x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
349	stp	x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
350.endm
351
352.macro restore_callee_saved_regs ctxt
353	// We require \ctxt is not x18-x28
354	ldr	x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
355	ldp	x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
356	ldp	x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
357	ldp	x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
358	ldp	x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
359	ldp	x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
360	ldp	x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
361.endm
362
363.macro save_sp_el0 ctxt, tmp
364	mrs	\tmp,	sp_el0
365	str	\tmp,	[\ctxt, #CPU_SP_EL0_OFFSET]
366.endm
367
368.macro restore_sp_el0 ctxt, tmp
369	ldr	\tmp,	  [\ctxt, #CPU_SP_EL0_OFFSET]
370	msr	sp_el0, \tmp
371.endm
372
373#endif
374
375#endif /* __ARM_KVM_ASM_H__ */
376