aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm64/kvm/hyp-init.S
blob: 4072d408a4b49f8d78677ca941553d5f73a5ff3d (plain) (blame)
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
/*
 * Copyright (C) 2012,2013 - ARM Ltd
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/linkage.h>

#include <asm/assembler.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_mmu.h>
#include <asm/pgtable-hwdef.h>
#include <asm/sysreg.h>
#include <asm/virt.h>

	.text
	.pushsection	.hyp.idmap.text, "ax"

	.align	11

ENTRY(__kvm_hyp_init)
	ventry	__invalid		// Synchronous EL2t
	ventry	__invalid		// IRQ EL2t
	ventry	__invalid		// FIQ EL2t
	ventry	__invalid		// Error EL2t

	ventry	__invalid		// Synchronous EL2h
	ventry	__invalid		// IRQ EL2h
	ventry	__invalid		// FIQ EL2h
	ventry	__invalid		// Error EL2h

	ventry	__do_hyp_init		// Synchronous 64-bit EL1
	ventry	__invalid		// IRQ 64-bit EL1
	ventry	__invalid		// FIQ 64-bit EL1
	ventry	__invalid		// Error 64-bit EL1

	ventry	__invalid		// Synchronous 32-bit EL1
	ventry	__invalid		// IRQ 32-bit EL1
	ventry	__invalid		// FIQ 32-bit EL1
	ventry	__invalid		// Error 32-bit EL1

__invalid:
	b	.

	/*
	 * x0: HYP pgd
	 * x1: HYP stack
	 * x2: HYP vectors
	 */
__do_hyp_init:
	/* Check for a stub HVC call */
	cmp	x0, #HVC_STUB_HCALL_NR
	b.lo	__kvm_handle_stub_hvc

	msr	ttbr0_el2, x0

	mrs	x4, tcr_el1
	ldr	x5, =TCR_EL2_MASK
	and	x4, x4, x5
	mov	x5, #TCR_EL2_RES1
	orr	x4, x4, x5

#ifndef CONFIG_ARM64_VA_BITS_48
	/*
	 * If we are running with VA_BITS < 48, we may be running with an extra
	 * level of translation in the ID map. This is only the case if system
	 * RAM is out of range for the currently configured page size and number
	 * of translation levels, in which case we will also need the extra
	 * level for the HYP ID map, or we won't be able to enable the EL2 MMU.
	 *
	 * However, at EL2, there is only one TTBR register, and we can't switch
	 * between translation tables *and* update TCR_EL2.T0SZ at the same
	 * time. Bottom line: we need the extra level in *both* our translation
	 * tables.
	 *
	 * So use the same T0SZ value we use for the ID map.
	 */
	ldr_l	x5, idmap_t0sz
	bfi	x4, x5, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH
#endif
	/*
	 * Read the PARange bits from ID_AA64MMFR0_EL1 and set the PS bits in
	 * TCR_EL2.
	 */
	mrs	x5, ID_AA64MMFR0_EL1
	bfi	x4, x5, #16, #3

	msr	tcr_el2, x4

	mrs	x4, mair_el1
	msr	mair_el2, x4
	isb

	/* Invalidate the stale TLBs from Bootloader */
	tlbi	alle2
	dsb	sy

	/*
	 * Preserve all the RES1 bits while setting the default flags,
	 * as well as the EE bit on BE.
	 */
	ldr	x4, =(SCTLR_EL2_RES1 | SCTLR_ELx_FLAGS)
CPU_BE(	orr	x4, x4, #SCTLR_ELx_EE)
	msr	sctlr_el2, x4
	isb

	/* Set the stack and new vectors */
	kern_hyp_va	x1
	mov	sp, x1
	kern_hyp_va	x2
	msr	vbar_el2, x2

	/* Hello, World! */
	eret
ENDPROC(__kvm_hyp_init)

ENTRY(__kvm_handle_stub_hvc)
	cmp	x0, #HVC_SOFT_RESTART
	b.ne	1f

	/* This is where we're about to jump, staying at EL2 */
	msr	elr_el2, x1
	mov	x0, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT | PSR_MODE_EL2h)
	msr	spsr_el2, x0

	/* Shuffle the arguments, and don't come back */
	mov	x0, x2
	mov	x1, x3
	mov	x2, x4
	b	reset

1:	cmp	x0, #HVC_RESET_VECTORS
	b.ne	1f
reset:
	/*
	 * Reset kvm back to the hyp stub. Do not clobber x0-x4 in
	 * case we coming via HVC_SOFT_RESTART.
	 */
	mrs	x5, sctlr_el2
	ldr	x6, =SCTLR_ELx_FLAGS
	bic	x5, x5, x6		// Clear SCTL_M and etc
	msr	sctlr_el2, x5
	isb

	/* Install stub vectors */
	adr_l	x5, __hyp_stub_vectors
	msr	vbar_el2, x5
	mov	x0, xzr
	eret

1:	/* Bad stub call */
	ldr	x0, =HVC_STUB_ERR
	eret

ENDPROC(__kvm_handle_stub_hvc)

	.ltorg

	.popsection