xref: /openbmc/linux/arch/arm64/kernel/hyp-stub.S (revision 1a59d1b8)
1/*
2 * Hypervisor stub
3 *
4 * Copyright (C) 2012 ARM Ltd.
5 * Author:	Marc Zyngier <marc.zyngier@arm.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/init.h>
21#include <linux/linkage.h>
22#include <linux/irqchip/arm-gic-v3.h>
23
24#include <asm/assembler.h>
25#include <asm/kvm_arm.h>
26#include <asm/kvm_asm.h>
27#include <asm/ptrace.h>
28#include <asm/virt.h>
29
30	.text
31	.pushsection	.hyp.text, "ax"
32
33	.align 11
34
35ENTRY(__hyp_stub_vectors)
36	ventry	el2_sync_invalid		// Synchronous EL2t
37	ventry	el2_irq_invalid			// IRQ EL2t
38	ventry	el2_fiq_invalid			// FIQ EL2t
39	ventry	el2_error_invalid		// Error EL2t
40
41	ventry	el2_sync_invalid		// Synchronous EL2h
42	ventry	el2_irq_invalid			// IRQ EL2h
43	ventry	el2_fiq_invalid			// FIQ EL2h
44	ventry	el2_error_invalid		// Error EL2h
45
46	ventry	el1_sync			// Synchronous 64-bit EL1
47	ventry	el1_irq_invalid			// IRQ 64-bit EL1
48	ventry	el1_fiq_invalid			// FIQ 64-bit EL1
49	ventry	el1_error_invalid		// Error 64-bit EL1
50
51	ventry	el1_sync_invalid		// Synchronous 32-bit EL1
52	ventry	el1_irq_invalid			// IRQ 32-bit EL1
53	ventry	el1_fiq_invalid			// FIQ 32-bit EL1
54	ventry	el1_error_invalid		// Error 32-bit EL1
55ENDPROC(__hyp_stub_vectors)
56
57	.align 11
58
59el1_sync:
60	cmp	x0, #HVC_SET_VECTORS
61	b.ne	2f
62	msr	vbar_el2, x1
63	b	9f
64
652:	cmp	x0, #HVC_SOFT_RESTART
66	b.ne	3f
67	mov	x0, x2
68	mov	x2, x4
69	mov	x4, x1
70	mov	x1, x3
71	br	x4				// no return
72
733:	cmp	x0, #HVC_RESET_VECTORS
74	beq	9f				// Nothing to reset!
75
76	/* Someone called kvm_call_hyp() against the hyp-stub... */
77	ldr	x0, =HVC_STUB_ERR
78	eret
79
809:	mov	x0, xzr
81	eret
82ENDPROC(el1_sync)
83
84.macro invalid_vector	label
85\label:
86	b \label
87ENDPROC(\label)
88.endm
89
90	invalid_vector	el2_sync_invalid
91	invalid_vector	el2_irq_invalid
92	invalid_vector	el2_fiq_invalid
93	invalid_vector	el2_error_invalid
94	invalid_vector	el1_sync_invalid
95	invalid_vector	el1_irq_invalid
96	invalid_vector	el1_fiq_invalid
97	invalid_vector	el1_error_invalid
98
99/*
100 * __hyp_set_vectors: Call this after boot to set the initial hypervisor
101 * vectors as part of hypervisor installation.  On an SMP system, this should
102 * be called on each CPU.
103 *
104 * x0 must be the physical address of the new vector table, and must be
105 * 2KB aligned.
106 *
107 * Before calling this, you must check that the stub hypervisor is installed
108 * everywhere, by waiting for any secondary CPUs to be brought up and then
109 * checking that is_hyp_mode_available() is true.
110 *
111 * If not, there is a pre-existing hypervisor, some CPUs failed to boot, or
112 * something else went wrong... in such cases, trying to install a new
113 * hypervisor is unlikely to work as desired.
114 *
115 * When you call into your shiny new hypervisor, sp_el2 will contain junk,
116 * so you will need to set that to something sensible at the new hypervisor's
117 * initialisation entry point.
118 */
119
120ENTRY(__hyp_set_vectors)
121	mov	x1, x0
122	mov	x0, #HVC_SET_VECTORS
123	hvc	#0
124	ret
125ENDPROC(__hyp_set_vectors)
126
127ENTRY(__hyp_reset_vectors)
128	mov	x0, #HVC_RESET_VECTORS
129	hvc	#0
130	ret
131ENDPROC(__hyp_reset_vectors)
132