aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm64/include/asm/kvm_asm.h
blob: 6f98fbd0ac8162cc1b165aea059b68bbb20af4ae (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2012,2013 - ARM Ltd
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 */

#ifndef __ARM_KVM_ASM_H__
#define __ARM_KVM_ASM_H__

#include <asm/virt.h>

#define	VCPU_WORKAROUND_2_FLAG_SHIFT	0
#define	VCPU_WORKAROUND_2_FLAG		(_AC(1, UL) << VCPU_WORKAROUND_2_FLAG_SHIFT)

#define ARM_EXIT_WITH_SERROR_BIT  31
#define ARM_EXCEPTION_CODE(x)	  ((x) & ~(1U << ARM_EXIT_WITH_SERROR_BIT))
#define ARM_EXCEPTION_IS_TRAP(x)  (ARM_EXCEPTION_CODE((x)) == ARM_EXCEPTION_TRAP)
#define ARM_SERROR_PENDING(x)	  !!((x) & (1U << ARM_EXIT_WITH_SERROR_BIT))

#define ARM_EXCEPTION_IRQ	  0
#define ARM_EXCEPTION_EL1_SERROR  1
#define ARM_EXCEPTION_TRAP	  2
#define ARM_EXCEPTION_IL	  3
/* The hyp-stub will return this for any kvm_call_hyp() call */
#define ARM_EXCEPTION_HYP_GONE	  HVC_STUB_ERR

#define kvm_arm_exception_type					\
	{ARM_EXCEPTION_IRQ,		"IRQ"		},	\
	{ARM_EXCEPTION_EL1_SERROR, 	"SERROR"	},	\
	{ARM_EXCEPTION_TRAP, 		"TRAP"		},	\
	{ARM_EXCEPTION_HYP_GONE,	"HYP_GONE"	}

/*
 * Size of the HYP vectors preamble. kvm_patch_vector_branch() generates code
 * that jumps over this.
 */
#define KVM_VECTOR_PREAMBLE	(2 * AARCH64_INSN_SIZE)

#define __SMCCC_WORKAROUND_1_SMC_SZ 36

#ifndef __ASSEMBLY__

#include <linux/mm.h>

/*
 * Translate name of a symbol defined in nVHE hyp to the name seen
 * by kernel proper. All nVHE symbols are prefixed by the build system
 * to avoid clashes with the VHE variants.
 */
#define kvm_nvhe_sym(sym)	__kvm_nvhe_##sym

#define DECLARE_KVM_VHE_SYM(sym)	extern char sym[]
#define DECLARE_KVM_NVHE_SYM(sym)	extern char kvm_nvhe_sym(sym)[]

/*
 * Define a pair of symbols sharing the same name but one defined in
 * VHE and the other in nVHE hyp implementations.
 */
#define DECLARE_KVM_HYP_SYM(sym)		\
	DECLARE_KVM_VHE_SYM(sym);		\
	DECLARE_KVM_NVHE_SYM(sym)

#define CHOOSE_VHE_SYM(sym)	sym
#define CHOOSE_NVHE_SYM(sym)	kvm_nvhe_sym(sym)

#ifndef __KVM_NVHE_HYPERVISOR__
/*
 * BIG FAT WARNINGS:
 *
 * - Don't be tempted to change the following is_kernel_in_hyp_mode()
 *   to has_vhe(). has_vhe() is implemented as a *final* capability,
 *   while this is used early at boot time, when the capabilities are
 *   not final yet....
 *
 * - Don't let the nVHE hypervisor have access to this, as it will
 *   pick the *wrong* symbol (yes, it runs at EL2...).
 */
#define CHOOSE_HYP_SYM(sym)	(is_kernel_in_hyp_mode() ? CHOOSE_VHE_SYM(sym) \
					   : CHOOSE_NVHE_SYM(sym))
#else
/* The nVHE hypervisor shouldn't even try to access anything */
extern void *__nvhe_undefined_symbol;
#define CHOOSE_HYP_SYM(sym)	__nvhe_undefined_symbol
#endif

/* Translate a kernel address @ptr into its equivalent linear mapping */
#define kvm_ksym_ref(ptr)						\
	({								\
		void *val = (ptr);					\
		if (!is_kernel_in_hyp_mode())				\
			val = lm_alias((ptr));				\
		val;							\
	 })
#define kvm_ksym_ref_nvhe(sym)	kvm_ksym_ref(kvm_nvhe_sym(sym))

struct kvm;
struct kvm_vcpu;
struct kvm_s2_mmu;

DECLARE_KVM_NVHE_SYM(__kvm_hyp_init);
DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
#define __kvm_hyp_init		CHOOSE_NVHE_SYM(__kvm_hyp_init)
#define __kvm_hyp_vector	CHOOSE_HYP_SYM(__kvm_hyp_vector)

#ifdef CONFIG_KVM_INDIRECT_VECTORS
extern atomic_t arm64_el2_vector_last_slot;
DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs);
#define __bp_harden_hyp_vecs	CHOOSE_HYP_SYM(__bp_harden_hyp_vecs)
#endif

extern void __kvm_flush_vm_context(void);
extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa,
				     int level);
extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
extern void __kvm_tlb_flush_local_vmid(struct kvm_s2_mmu *mmu);

extern void __kvm_timer_set_cntvoff(u64 cntvoff);

extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);

extern void __kvm_enable_ssbs(void);

extern u64 __vgic_v3_get_ich_vtr_el2(void);
extern u64 __vgic_v3_read_vmcr(void);
extern void __vgic_v3_write_vmcr(u32 vmcr);
extern void __vgic_v3_init_lrs(void);

extern u32 __kvm_get_mdcr_el2(void);

extern char __smccc_workaround_1_smc[__SMCCC_WORKAROUND_1_SMC_SZ];

/*
 * Obtain the PC-relative address of a kernel symbol
 * s: symbol
 *
 * The goal of this macro is to return a symbol's address based on a
 * PC-relative computation, as opposed to a loading the VA from a
 * constant pool or something similar. This works well for HYP, as an
 * absolute VA is guaranteed to be wrong. Only use this if trying to
 * obtain the address of a symbol (i.e. not something you obtained by
 * following a pointer).
 */
#define hyp_symbol_addr(s)						\
	({								\
		typeof(s) *addr;					\
		asm("adrp	%0, %1\n"				\
		    "add	%0, %0, :lo12:%1\n"			\
		    : "=r" (addr) : "S" (&s));				\
		addr;							\
	})

/*
 * Home-grown __this_cpu_{ptr,read} variants that always work at HYP,
 * provided that sym is really a *symbol* and not a pointer obtained from
 * a data structure. As for SHIFT_PERCPU_PTR(), the creative casting keeps
 * sparse quiet.
 */
#define __hyp_this_cpu_ptr(sym)						\
	({								\
		void *__ptr;						\
		__verify_pcpu_ptr(&sym);				\
		__ptr = hyp_symbol_addr(sym);				\
		__ptr += read_sysreg(tpidr_el2);			\
		(typeof(sym) __kernel __force *)__ptr;			\
	 })

#define __hyp_this_cpu_read(sym)					\
	({								\
		*__hyp_this_cpu_ptr(sym);				\
	 })

#define __KVM_EXTABLE(from, to)						\
	"	.pushsection	__kvm_ex_table, \"a\"\n"		\
	"	.align		3\n"					\
	"	.long		(" #from " - .), (" #to " - .)\n"	\
	"	.popsection\n"


#define __kvm_at(at_op, addr)						\
( { 									\
	int __kvm_at_err = 0;						\
	u64 spsr, elr;							\
	asm volatile(							\
	"	mrs	%1, spsr_el2\n"					\
	"	mrs	%2, elr_el2\n"					\
	"1:	at	"at_op", %3\n"					\
	"	isb\n"							\
	"	b	9f\n"						\
	"2:	msr	spsr_el2, %1\n"					\
	"	msr	elr_el2, %2\n"					\
	"	mov	%w0, %4\n"					\
	"9:\n"								\
	__KVM_EXTABLE(1b, 2b)						\
	: "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr)		\
	: "r" (addr), "i" (-EFAULT));					\
	__kvm_at_err;							\
} )


#else /* __ASSEMBLY__ */

.macro hyp_adr_this_cpu reg, sym, tmp
	adr_l	\reg, \sym
	mrs	\tmp, tpidr_el2
	add	\reg, \reg, \tmp
.endm

.macro hyp_ldr_this_cpu reg, sym, tmp
	adr_l	\reg, \sym
	mrs	\tmp, tpidr_el2
	ldr	\reg,  [\reg, \tmp]
.endm

.macro get_host_ctxt reg, tmp
	hyp_adr_this_cpu \reg, kvm_host_data, \tmp
	add	\reg, \reg, #HOST_DATA_CONTEXT
.endm

.macro get_vcpu_ptr vcpu, ctxt
	get_host_ctxt \ctxt, \vcpu
	ldr	\vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
.endm

/*
 * KVM extable for unexpected exceptions.
 * In the same format _asm_extable, but output to a different section so that
 * it can be mapped to EL2. The KVM version is not sorted. The caller must
 * ensure:
 * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
 * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
 */
.macro	_kvm_extable, from, to
	.pushsection	__kvm_ex_table, "a"
	.align		3
	.long		(\from - .), (\to - .)
	.popsection
.endm

#endif

#endif /* __ARM_KVM_ASM_H__ */