2 * Copyright (C) 2012,2013 - ARM Ltd
3 * Author: Marc Zyngier <marc.zyngier@arm.com>
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>
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.
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.
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/>.
22 #include <linux/kvm.h>
23 #include <linux/kvm_host.h>
26 #include <asm/kvm_asm.h>
27 #include <asm/kvm_coproc.h>
28 #include <asm/kvm_emulate.h>
29 #include <asm/kvm_mmu.h>
30 #include <asm/kvm_psci.h>
31 #include <asm/debug-monitors.h>
33 #define CREATE_TRACE_POINTS
36 typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *);
38 static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
42 trace_kvm_hvc_arm64(*vcpu_pc(vcpu), vcpu_get_reg(vcpu, 0),
43 kvm_vcpu_hvc_get_imm(vcpu));
44 vcpu->stat.hvc_exit_stat++;
46 ret = kvm_psci_call(vcpu);
48 vcpu_set_reg(vcpu, 0, ~0UL);
55 static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
57 vcpu_set_reg(vcpu, 0, ~0UL);
62 * Guest access to FP/ASIMD registers are routed to this handler only
63 * when the system doesn't support FP/ASIMD.
65 static int handle_no_fpsimd(struct kvm_vcpu *vcpu, struct kvm_run *run)
67 kvm_inject_undefined(vcpu);
72 * kvm_handle_wfx - handle a wait-for-interrupts or wait-for-event
73 * instruction executed by a guest
75 * @vcpu: the vcpu pointer
77 * WFE: Yield the CPU and come back to this vcpu when the scheduler
79 * WFI: Simply call kvm_vcpu_block(), which will halt execution of
80 * world-switches and schedule other host processes until there is an
81 * incoming IRQ or FIQ to the VM.
83 static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
85 if (kvm_vcpu_get_hsr(vcpu) & ESR_ELx_WFx_ISS_WFE) {
86 trace_kvm_wfx_arm64(*vcpu_pc(vcpu), true);
87 vcpu->stat.wfe_exit_stat++;
88 kvm_vcpu_on_spin(vcpu, vcpu_mode_priv(vcpu));
90 trace_kvm_wfx_arm64(*vcpu_pc(vcpu), false);
91 vcpu->stat.wfi_exit_stat++;
93 kvm_clear_request(KVM_REQ_UNHALT, vcpu);
96 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
102 * kvm_handle_guest_debug - handle a debug exception instruction
104 * @vcpu: the vcpu pointer
105 * @run: access to the kvm_run structure for results
107 * We route all debug exceptions through the same handler. If both the
108 * guest and host are using the same debug facilities it will be up to
109 * userspace to re-inject the correct exception for guest delivery.
111 * @return: 0 (while setting run->exit_reason), -1 for error
113 static int kvm_handle_guest_debug(struct kvm_vcpu *vcpu, struct kvm_run *run)
115 u32 hsr = kvm_vcpu_get_hsr(vcpu);
118 run->exit_reason = KVM_EXIT_DEBUG;
119 run->debug.arch.hsr = hsr;
121 switch (ESR_ELx_EC(hsr)) {
122 case ESR_ELx_EC_WATCHPT_LOW:
123 run->debug.arch.far = vcpu->arch.fault.far_el2;
125 case ESR_ELx_EC_SOFTSTP_LOW:
126 case ESR_ELx_EC_BREAKPT_LOW:
127 case ESR_ELx_EC_BKPT32:
128 case ESR_ELx_EC_BRK64:
131 kvm_err("%s: un-handled case hsr: %#08x\n",
132 __func__, (unsigned int) hsr);
140 static int kvm_handle_unknown_ec(struct kvm_vcpu *vcpu, struct kvm_run *run)
142 u32 hsr = kvm_vcpu_get_hsr(vcpu);
144 kvm_pr_unimpl("Unknown exception class: hsr: %#08x -- %s\n",
145 hsr, esr_get_class_string(hsr));
147 kvm_inject_undefined(vcpu);
151 static int handle_sve(struct kvm_vcpu *vcpu, struct kvm_run *run)
153 /* Until SVE is supported for guests: */
154 kvm_inject_undefined(vcpu);
158 static exit_handle_fn arm_exit_handlers[] = {
159 [0 ... ESR_ELx_EC_MAX] = kvm_handle_unknown_ec,
160 [ESR_ELx_EC_WFx] = kvm_handle_wfx,
161 [ESR_ELx_EC_CP15_32] = kvm_handle_cp15_32,
162 [ESR_ELx_EC_CP15_64] = kvm_handle_cp15_64,
163 [ESR_ELx_EC_CP14_MR] = kvm_handle_cp14_32,
164 [ESR_ELx_EC_CP14_LS] = kvm_handle_cp14_load_store,
165 [ESR_ELx_EC_CP14_64] = kvm_handle_cp14_64,
166 [ESR_ELx_EC_HVC32] = handle_hvc,
167 [ESR_ELx_EC_SMC32] = handle_smc,
168 [ESR_ELx_EC_HVC64] = handle_hvc,
169 [ESR_ELx_EC_SMC64] = handle_smc,
170 [ESR_ELx_EC_SYS64] = kvm_handle_sys_reg,
171 [ESR_ELx_EC_SVE] = handle_sve,
172 [ESR_ELx_EC_IABT_LOW] = kvm_handle_guest_abort,
173 [ESR_ELx_EC_DABT_LOW] = kvm_handle_guest_abort,
174 [ESR_ELx_EC_SOFTSTP_LOW]= kvm_handle_guest_debug,
175 [ESR_ELx_EC_WATCHPT_LOW]= kvm_handle_guest_debug,
176 [ESR_ELx_EC_BREAKPT_LOW]= kvm_handle_guest_debug,
177 [ESR_ELx_EC_BKPT32] = kvm_handle_guest_debug,
178 [ESR_ELx_EC_BRK64] = kvm_handle_guest_debug,
179 [ESR_ELx_EC_FP_ASIMD] = handle_no_fpsimd,
182 static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
184 u32 hsr = kvm_vcpu_get_hsr(vcpu);
185 u8 hsr_ec = ESR_ELx_EC(hsr);
187 return arm_exit_handlers[hsr_ec];
191 * We may be single-stepping an emulated instruction. If the emulation
192 * has been completed in the kernel, we can return to userspace with a
193 * KVM_EXIT_DEBUG, otherwise userspace needs to complete its
196 static int handle_trap_exceptions(struct kvm_vcpu *vcpu, struct kvm_run *run)
201 * See ARM ARM B1.14.1: "Hyp traps on instructions
202 * that fail their condition code check"
204 if (!kvm_condition_valid(vcpu)) {
205 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
208 exit_handle_fn exit_handler;
210 exit_handler = kvm_get_exit_handler(vcpu);
211 handled = exit_handler(vcpu, run);
215 * kvm_arm_handle_step_debug() sets the exit_reason on the kvm_run
216 * structure if we need to return to userspace.
218 if (handled > 0 && kvm_arm_handle_step_debug(vcpu, run))
225 * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
226 * proper exit to userspace.
228 int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
231 if (ARM_SERROR_PENDING(exception_index)) {
232 u8 hsr_ec = ESR_ELx_EC(kvm_vcpu_get_hsr(vcpu));
235 * HVC/SMC already have an adjusted PC, which we need
236 * to correct in order to return to after having
237 * injected the SError.
239 if (hsr_ec == ESR_ELx_EC_HVC32 || hsr_ec == ESR_ELx_EC_HVC64 ||
240 hsr_ec == ESR_ELx_EC_SMC32 || hsr_ec == ESR_ELx_EC_SMC64) {
241 u32 adj = kvm_vcpu_trap_il_is32bit(vcpu) ? 4 : 2;
242 *vcpu_pc(vcpu) -= adj;
245 kvm_inject_vabt(vcpu);
249 exception_index = ARM_EXCEPTION_CODE(exception_index);
251 switch (exception_index) {
252 case ARM_EXCEPTION_IRQ:
254 case ARM_EXCEPTION_EL1_SERROR:
255 kvm_inject_vabt(vcpu);
256 /* We may still need to return for single-step */
257 if (!(*vcpu_cpsr(vcpu) & DBG_SPSR_SS)
258 && kvm_arm_handle_step_debug(vcpu, run))
262 case ARM_EXCEPTION_TRAP:
263 return handle_trap_exceptions(vcpu, run);
264 case ARM_EXCEPTION_HYP_GONE:
266 * EL2 has been reset to the hyp-stub. This happens when a guest
267 * is pre-empted by kvm_reboot()'s shutdown call.
269 run->exit_reason = KVM_EXIT_FAIL_ENTRY;
272 kvm_pr_unimpl("Unsupported exception type: %d",
274 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;