xref: /openbmc/linux/arch/arm64/kernel/hyp-stub.S (revision d0e22329)
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	.align 11
32
33ENTRY(__hyp_stub_vectors)
34	ventry	el2_sync_invalid		// Synchronous EL2t
35	ventry	el2_irq_invalid			// IRQ EL2t
36	ventry	el2_fiq_invalid			// FIQ EL2t
37	ventry	el2_error_invalid		// Error EL2t
38
39	ventry	el2_sync_invalid		// Synchronous EL2h
40	ventry	el2_irq_invalid			// IRQ EL2h
41	ventry	el2_fiq_invalid			// FIQ EL2h
42	ventry	el2_error_invalid		// Error EL2h
43
44	ventry	el1_sync			// Synchronous 64-bit EL1
45	ventry	el1_irq_invalid			// IRQ 64-bit EL1
46	ventry	el1_fiq_invalid			// FIQ 64-bit EL1
47	ventry	el1_error_invalid		// Error 64-bit EL1
48
49	ventry	el1_sync_invalid		// Synchronous 32-bit EL1
50	ventry	el1_irq_invalid			// IRQ 32-bit EL1
51	ventry	el1_fiq_invalid			// FIQ 32-bit EL1
52	ventry	el1_error_invalid		// Error 32-bit EL1
53ENDPROC(__hyp_stub_vectors)
54
55	.align 11
56
57el1_sync:
58	cmp	x0, #HVC_SET_VECTORS
59	b.ne	2f
60	msr	vbar_el2, x1
61	b	9f
62
632:	cmp	x0, #HVC_SOFT_RESTART
64	b.ne	3f
65	mov	x0, x2
66	mov	x2, x4
67	mov	x4, x1
68	mov	x1, x3
69	br	x4				// no return
70
713:	cmp	x0, #HVC_RESET_VECTORS
72	beq	9f				// Nothing to reset!
73
74	/* Someone called kvm_call_hyp() against the hyp-stub... */
75	ldr	x0, =HVC_STUB_ERR
76	eret
77
789:	mov	x0, xzr
79	eret
80ENDPROC(el1_sync)
81
82.macro invalid_vector	label
83\label:
84	b \label
85ENDPROC(\label)
86.endm
87
88	invalid_vector	el2_sync_invalid
89	invalid_vector	el2_irq_invalid
90	invalid_vector	el2_fiq_invalid
91	invalid_vector	el2_error_invalid
92	invalid_vector	el1_sync_invalid
93	invalid_vector	el1_irq_invalid
94	invalid_vector	el1_fiq_invalid
95	invalid_vector	el1_error_invalid
96
97/*
98 * __hyp_set_vectors: Call this after boot to set the initial hypervisor
99 * vectors as part of hypervisor installation.  On an SMP system, this should
100 * be called on each CPU.
101 *
102 * x0 must be the physical address of the new vector table, and must be
103 * 2KB aligned.
104 *
105 * Before calling this, you must check that the stub hypervisor is installed
106 * everywhere, by waiting for any secondary CPUs to be brought up and then
107 * checking that is_hyp_mode_available() is true.
108 *
109 * If not, there is a pre-existing hypervisor, some CPUs failed to boot, or
110 * something else went wrong... in such cases, trying to install a new
111 * hypervisor is unlikely to work as desired.
112 *
113 * When you call into your shiny new hypervisor, sp_el2 will contain junk,
114 * so you will need to set that to something sensible at the new hypervisor's
115 * initialisation entry point.
116 */
117
118ENTRY(__hyp_set_vectors)
119	mov	x1, x0
120	mov	x0, #HVC_SET_VECTORS
121	hvc	#0
122	ret
123ENDPROC(__hyp_set_vectors)
124
125ENTRY(__hyp_reset_vectors)
126	mov	x0, #HVC_RESET_VECTORS
127	hvc	#0
128	ret
129ENDPROC(__hyp_reset_vectors)
130