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arm64: KVM: Get rid of old vcpu_reg()
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1 /*
2  * Copyright (C) 2012,2013 - ARM Ltd
3  * Author: Marc Zyngier <marc.zyngier@arm.com>
4  *
5  * Derived from arch/arm/kvm/handle_exit.c:
6  * Copyright (C) 2012 - Virtual Open Systems and Columbia University
7  * Author: Christoffer Dall <c.dall@virtualopensystems.com>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
20  */
21
22 #include <linux/kvm.h>
23 #include <linux/kvm_host.h>
24
25 #include <asm/esr.h>
26 #include <asm/kvm_coproc.h>
27 #include <asm/kvm_emulate.h>
28 #include <asm/kvm_mmu.h>
29 #include <asm/kvm_psci.h>
30
31 #define CREATE_TRACE_POINTS
32 #include "trace.h"
33
34 typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *);
35
36 static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
37 {
38         int ret;
39
40         trace_kvm_hvc_arm64(*vcpu_pc(vcpu), vcpu_get_reg(vcpu, 0),
41                             kvm_vcpu_hvc_get_imm(vcpu));
42
43         ret = kvm_psci_call(vcpu);
44         if (ret < 0) {
45                 kvm_inject_undefined(vcpu);
46                 return 1;
47         }
48
49         return ret;
50 }
51
52 static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
53 {
54         kvm_inject_undefined(vcpu);
55         return 1;
56 }
57
58 /**
59  * kvm_handle_wfx - handle a wait-for-interrupts or wait-for-event
60  *                  instruction executed by a guest
61  *
62  * @vcpu:       the vcpu pointer
63  *
64  * WFE: Yield the CPU and come back to this vcpu when the scheduler
65  * decides to.
66  * WFI: Simply call kvm_vcpu_block(), which will halt execution of
67  * world-switches and schedule other host processes until there is an
68  * incoming IRQ or FIQ to the VM.
69  */
70 static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
71 {
72         if (kvm_vcpu_get_hsr(vcpu) & ESR_ELx_WFx_ISS_WFE) {
73                 trace_kvm_wfx_arm64(*vcpu_pc(vcpu), true);
74                 kvm_vcpu_on_spin(vcpu);
75         } else {
76                 trace_kvm_wfx_arm64(*vcpu_pc(vcpu), false);
77                 kvm_vcpu_block(vcpu);
78         }
79
80         kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
81
82         return 1;
83 }
84
85 /**
86  * kvm_handle_guest_debug - handle a debug exception instruction
87  *
88  * @vcpu:       the vcpu pointer
89  * @run:        access to the kvm_run structure for results
90  *
91  * We route all debug exceptions through the same handler. If both the
92  * guest and host are using the same debug facilities it will be up to
93  * userspace to re-inject the correct exception for guest delivery.
94  *
95  * @return: 0 (while setting run->exit_reason), -1 for error
96  */
97 static int kvm_handle_guest_debug(struct kvm_vcpu *vcpu, struct kvm_run *run)
98 {
99         u32 hsr = kvm_vcpu_get_hsr(vcpu);
100         int ret = 0;
101
102         run->exit_reason = KVM_EXIT_DEBUG;
103         run->debug.arch.hsr = hsr;
104
105         switch (hsr >> ESR_ELx_EC_SHIFT) {
106         case ESR_ELx_EC_WATCHPT_LOW:
107                 run->debug.arch.far = vcpu->arch.fault.far_el2;
108                 /* fall through */
109         case ESR_ELx_EC_SOFTSTP_LOW:
110         case ESR_ELx_EC_BREAKPT_LOW:
111         case ESR_ELx_EC_BKPT32:
112         case ESR_ELx_EC_BRK64:
113                 break;
114         default:
115                 kvm_err("%s: un-handled case hsr: %#08x\n",
116                         __func__, (unsigned int) hsr);
117                 ret = -1;
118                 break;
119         }
120
121         return ret;
122 }
123
124 static exit_handle_fn arm_exit_handlers[] = {
125         [ESR_ELx_EC_WFx]        = kvm_handle_wfx,
126         [ESR_ELx_EC_CP15_32]    = kvm_handle_cp15_32,
127         [ESR_ELx_EC_CP15_64]    = kvm_handle_cp15_64,
128         [ESR_ELx_EC_CP14_MR]    = kvm_handle_cp14_32,
129         [ESR_ELx_EC_CP14_LS]    = kvm_handle_cp14_load_store,
130         [ESR_ELx_EC_CP14_64]    = kvm_handle_cp14_64,
131         [ESR_ELx_EC_HVC32]      = handle_hvc,
132         [ESR_ELx_EC_SMC32]      = handle_smc,
133         [ESR_ELx_EC_HVC64]      = handle_hvc,
134         [ESR_ELx_EC_SMC64]      = handle_smc,
135         [ESR_ELx_EC_SYS64]      = kvm_handle_sys_reg,
136         [ESR_ELx_EC_IABT_LOW]   = kvm_handle_guest_abort,
137         [ESR_ELx_EC_DABT_LOW]   = kvm_handle_guest_abort,
138         [ESR_ELx_EC_SOFTSTP_LOW]= kvm_handle_guest_debug,
139         [ESR_ELx_EC_WATCHPT_LOW]= kvm_handle_guest_debug,
140         [ESR_ELx_EC_BREAKPT_LOW]= kvm_handle_guest_debug,
141         [ESR_ELx_EC_BKPT32]     = kvm_handle_guest_debug,
142         [ESR_ELx_EC_BRK64]      = kvm_handle_guest_debug,
143 };
144
145 static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
146 {
147         u32 hsr = kvm_vcpu_get_hsr(vcpu);
148         u8 hsr_ec = hsr >> ESR_ELx_EC_SHIFT;
149
150         if (hsr_ec >= ARRAY_SIZE(arm_exit_handlers) ||
151             !arm_exit_handlers[hsr_ec]) {
152                 kvm_err("Unknown exception class: hsr: %#08x -- %s\n",
153                         hsr, esr_get_class_string(hsr));
154                 BUG();
155         }
156
157         return arm_exit_handlers[hsr_ec];
158 }
159
160 /*
161  * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
162  * proper exit to userspace.
163  */
164 int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
165                        int exception_index)
166 {
167         exit_handle_fn exit_handler;
168
169         switch (exception_index) {
170         case ARM_EXCEPTION_IRQ:
171                 return 1;
172         case ARM_EXCEPTION_TRAP:
173                 /*
174                  * See ARM ARM B1.14.1: "Hyp traps on instructions
175                  * that fail their condition code check"
176                  */
177                 if (!kvm_condition_valid(vcpu)) {
178                         kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
179                         return 1;
180                 }
181
182                 exit_handler = kvm_get_exit_handler(vcpu);
183
184                 return exit_handler(vcpu, run);
185         default:
186                 kvm_pr_unimpl("Unsupported exception type: %d",
187                               exception_index);
188                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
189                 return 0;
190         }
191 }