xref: /linux/arch/arm64/kvm/hyp/hyp-entry.S (revision b6ebbac51bedf9e98e837688bc838f400196da5e)
1/*
2 * Copyright (C) 2015 - ARM Ltd
3 * Author: Marc Zyngier <marc.zyngier@arm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
16 */
17
18#include <linux/linkage.h>
19
20#include <asm/alternative.h>
21#include <asm/assembler.h>
22#include <asm/cpufeature.h>
23#include <asm/kvm_arm.h>
24#include <asm/kvm_asm.h>
25#include <asm/kvm_mmu.h>
26
27	.text
28	.pushsection	.hyp.text, "ax"
29
30.macro	save_x0_to_x3
31	stp	x0, x1, [sp, #-16]!
32	stp	x2, x3, [sp, #-16]!
33.endm
34
35.macro	restore_x0_to_x3
36	ldp	x2, x3, [sp], #16
37	ldp	x0, x1, [sp], #16
38.endm
39
40.macro do_el2_call
41	/*
42	 * Shuffle the parameters before calling the function
43	 * pointed to in x0. Assumes parameters in x[1,2,3].
44	 */
45	mov	lr, x0
46	mov	x0, x1
47	mov	x1, x2
48	mov	x2, x3
49	blr	lr
50.endm
51
52ENTRY(__vhe_hyp_call)
53	str	lr, [sp, #-16]!
54	do_el2_call
55	ldr	lr, [sp], #16
56	/*
57	 * We used to rely on having an exception return to get
58	 * an implicit isb. In the E2H case, we don't have it anymore.
59	 * rather than changing all the leaf functions, just do it here
60	 * before returning to the rest of the kernel.
61	 */
62	isb
63	ret
64ENDPROC(__vhe_hyp_call)
65
66/*
67 * Compute the idmap address of __kvm_hyp_reset based on the idmap
68 * start passed as a parameter, and jump there.
69 *
70 * x0: HYP phys_idmap_start
71 */
72ENTRY(__kvm_hyp_teardown)
73	mov	x4, x0
74	adr_l	x3, __kvm_hyp_reset
75
76	/* insert __kvm_hyp_reset()s offset into phys_idmap_start */
77	bfi	x4, x3, #0, #PAGE_SHIFT
78	br	x4
79ENDPROC(__kvm_hyp_teardown)
80
81el1_sync:				// Guest trapped into EL2
82	save_x0_to_x3
83
84alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
85	mrs	x1, esr_el2
86alternative_else
87	mrs	x1, esr_el1
88alternative_endif
89	lsr	x2, x1, #ESR_ELx_EC_SHIFT
90
91	cmp	x2, #ESR_ELx_EC_HVC64
92	b.ne	el1_trap
93
94	mrs	x3, vttbr_el2		// If vttbr is valid, the 64bit guest
95	cbnz	x3, el1_trap		// called HVC
96
97	/* Here, we're pretty sure the host called HVC. */
98	restore_x0_to_x3
99
100	cmp	x0, #HVC_GET_VECTORS
101	b.ne	1f
102	mrs	x0, vbar_el2
103	b	2f
104
1051:
106	/*
107	 * Perform the EL2 call
108	 */
109	kern_hyp_va	x0
110	do_el2_call
111
1122:	eret
113
114el1_trap:
115	/*
116	 * x1: ESR
117	 * x2: ESR_EC
118	 */
119
120	/* Guest accessed VFP/SIMD registers, save host, restore Guest */
121	cmp	x2, #ESR_ELx_EC_FP_ASIMD
122	b.eq	__fpsimd_guest_restore
123
124	mrs	x0, tpidr_el2
125	mov	x1, #ARM_EXCEPTION_TRAP
126	b	__guest_exit
127
128el1_irq:
129	save_x0_to_x3
130	mrs	x0, tpidr_el2
131	mov	x1, #ARM_EXCEPTION_IRQ
132	b	__guest_exit
133
134ENTRY(__hyp_do_panic)
135	mov	lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\
136		      PSR_MODE_EL1h)
137	msr	spsr_el2, lr
138	ldr	lr, =panic
139	msr	elr_el2, lr
140	eret
141ENDPROC(__hyp_do_panic)
142
143.macro invalid_vector	label, target = __hyp_panic
144	.align	2
145\label:
146	b \target
147ENDPROC(\label)
148.endm
149
150	/* None of these should ever happen */
151	invalid_vector	el2t_sync_invalid
152	invalid_vector	el2t_irq_invalid
153	invalid_vector	el2t_fiq_invalid
154	invalid_vector	el2t_error_invalid
155	invalid_vector	el2h_sync_invalid
156	invalid_vector	el2h_irq_invalid
157	invalid_vector	el2h_fiq_invalid
158	invalid_vector	el2h_error_invalid
159	invalid_vector	el1_sync_invalid
160	invalid_vector	el1_irq_invalid
161	invalid_vector	el1_fiq_invalid
162	invalid_vector	el1_error_invalid
163
164	.ltorg
165
166	.align 11
167
168ENTRY(__kvm_hyp_vector)
169	ventry	el2t_sync_invalid		// Synchronous EL2t
170	ventry	el2t_irq_invalid		// IRQ EL2t
171	ventry	el2t_fiq_invalid		// FIQ EL2t
172	ventry	el2t_error_invalid		// Error EL2t
173
174	ventry	el2h_sync_invalid		// Synchronous EL2h
175	ventry	el2h_irq_invalid		// IRQ EL2h
176	ventry	el2h_fiq_invalid		// FIQ EL2h
177	ventry	el2h_error_invalid		// Error EL2h
178
179	ventry	el1_sync			// Synchronous 64-bit EL1
180	ventry	el1_irq				// IRQ 64-bit EL1
181	ventry	el1_fiq_invalid			// FIQ 64-bit EL1
182	ventry	el1_error_invalid		// Error 64-bit EL1
183
184	ventry	el1_sync			// Synchronous 32-bit EL1
185	ventry	el1_irq				// IRQ 32-bit EL1
186	ventry	el1_fiq_invalid			// FIQ 32-bit EL1
187	ventry	el1_error_invalid		// Error 32-bit EL1
188ENDPROC(__kvm_hyp_vector)
189