2 * Copyright (C) 2012-2015 - ARM Ltd
3 * Author: Marc Zyngier <marc.zyngier@arm.com>
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.
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.
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/>.
18 #include <linux/compiler.h>
19 #include <linux/kvm_host.h>
21 #include <asm/kprobes.h>
22 #include <asm/kvm_asm.h>
23 #include <asm/kvm_emulate.h>
24 #include <asm/kvm_hyp.h>
27 * Non-VHE: Both host and guest must save everything.
29 * VHE: Host and guest must save mdscr_el1 and sp_el0 (and the PC and pstate,
30 * which are handled as part of the el2 return state) on every switch.
31 * tpidr_el0 and tpidrro_el0 only need to be switched when going
32 * to host userspace or a different VCPU. EL1 registers only need to be
33 * switched when potentially going to run a different VCPU. The latter two
34 * classes are handled as part of kvm_arch_vcpu_load and kvm_arch_vcpu_put.
37 static void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt)
39 ctxt->sys_regs[MDSCR_EL1] = read_sysreg(mdscr_el1);
42 * The host arm64 Linux uses sp_el0 to point to 'current' and it must
43 * therefore be saved/restored on every entry/exit to/from the guest.
45 ctxt->gp_regs.regs.sp = read_sysreg(sp_el0);
48 static void __hyp_text __sysreg_save_user_state(struct kvm_cpu_context *ctxt)
50 ctxt->sys_regs[TPIDR_EL0] = read_sysreg(tpidr_el0);
51 ctxt->sys_regs[TPIDRRO_EL0] = read_sysreg(tpidrro_el0);
54 static void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
56 ctxt->sys_regs[CSSELR_EL1] = read_sysreg(csselr_el1);
57 ctxt->sys_regs[SCTLR_EL1] = read_sysreg_el1(sctlr);
58 ctxt->sys_regs[ACTLR_EL1] = read_sysreg(actlr_el1);
59 ctxt->sys_regs[CPACR_EL1] = read_sysreg_el1(cpacr);
60 ctxt->sys_regs[TTBR0_EL1] = read_sysreg_el1(ttbr0);
61 ctxt->sys_regs[TTBR1_EL1] = read_sysreg_el1(ttbr1);
62 ctxt->sys_regs[TCR_EL1] = read_sysreg_el1(tcr);
63 ctxt->sys_regs[ESR_EL1] = read_sysreg_el1(esr);
64 ctxt->sys_regs[AFSR0_EL1] = read_sysreg_el1(afsr0);
65 ctxt->sys_regs[AFSR1_EL1] = read_sysreg_el1(afsr1);
66 ctxt->sys_regs[FAR_EL1] = read_sysreg_el1(far);
67 ctxt->sys_regs[MAIR_EL1] = read_sysreg_el1(mair);
68 ctxt->sys_regs[VBAR_EL1] = read_sysreg_el1(vbar);
69 ctxt->sys_regs[CONTEXTIDR_EL1] = read_sysreg_el1(contextidr);
70 ctxt->sys_regs[AMAIR_EL1] = read_sysreg_el1(amair);
71 ctxt->sys_regs[CNTKCTL_EL1] = read_sysreg_el1(cntkctl);
72 ctxt->sys_regs[PAR_EL1] = read_sysreg(par_el1);
73 ctxt->sys_regs[TPIDR_EL1] = read_sysreg(tpidr_el1);
75 ctxt->gp_regs.sp_el1 = read_sysreg(sp_el1);
76 ctxt->gp_regs.elr_el1 = read_sysreg_el1(elr);
77 ctxt->gp_regs.spsr[KVM_SPSR_EL1]= read_sysreg_el1(spsr);
80 static void __hyp_text __sysreg_save_el2_return_state(struct kvm_cpu_context *ctxt)
82 ctxt->gp_regs.regs.pc = read_sysreg_el2(elr);
83 ctxt->gp_regs.regs.pstate = read_sysreg_el2(spsr);
85 if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN))
86 ctxt->sys_regs[DISR_EL1] = read_sysreg_s(SYS_VDISR_EL2);
89 void __hyp_text __sysreg_save_state_nvhe(struct kvm_cpu_context *ctxt)
91 __sysreg_save_el1_state(ctxt);
92 __sysreg_save_common_state(ctxt);
93 __sysreg_save_user_state(ctxt);
94 __sysreg_save_el2_return_state(ctxt);
97 void sysreg_save_host_state_vhe(struct kvm_cpu_context *ctxt)
99 __sysreg_save_common_state(ctxt);
101 NOKPROBE_SYMBOL(sysreg_save_host_state_vhe);
103 void sysreg_save_guest_state_vhe(struct kvm_cpu_context *ctxt)
105 __sysreg_save_common_state(ctxt);
106 __sysreg_save_el2_return_state(ctxt);
108 NOKPROBE_SYMBOL(sysreg_save_guest_state_vhe);
110 static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctxt)
112 write_sysreg(ctxt->sys_regs[MDSCR_EL1], mdscr_el1);
115 * The host arm64 Linux uses sp_el0 to point to 'current' and it must
116 * therefore be saved/restored on every entry/exit to/from the guest.
118 write_sysreg(ctxt->gp_regs.regs.sp, sp_el0);
121 static void __hyp_text __sysreg_restore_user_state(struct kvm_cpu_context *ctxt)
123 write_sysreg(ctxt->sys_regs[TPIDR_EL0], tpidr_el0);
124 write_sysreg(ctxt->sys_regs[TPIDRRO_EL0], tpidrro_el0);
127 static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
129 write_sysreg(ctxt->sys_regs[MPIDR_EL1], vmpidr_el2);
130 write_sysreg(ctxt->sys_regs[CSSELR_EL1], csselr_el1);
131 write_sysreg_el1(ctxt->sys_regs[SCTLR_EL1], sctlr);
132 write_sysreg(ctxt->sys_regs[ACTLR_EL1], actlr_el1);
133 write_sysreg_el1(ctxt->sys_regs[CPACR_EL1], cpacr);
134 write_sysreg_el1(ctxt->sys_regs[TTBR0_EL1], ttbr0);
135 write_sysreg_el1(ctxt->sys_regs[TTBR1_EL1], ttbr1);
136 write_sysreg_el1(ctxt->sys_regs[TCR_EL1], tcr);
137 write_sysreg_el1(ctxt->sys_regs[ESR_EL1], esr);
138 write_sysreg_el1(ctxt->sys_regs[AFSR0_EL1], afsr0);
139 write_sysreg_el1(ctxt->sys_regs[AFSR1_EL1], afsr1);
140 write_sysreg_el1(ctxt->sys_regs[FAR_EL1], far);
141 write_sysreg_el1(ctxt->sys_regs[MAIR_EL1], mair);
142 write_sysreg_el1(ctxt->sys_regs[VBAR_EL1], vbar);
143 write_sysreg_el1(ctxt->sys_regs[CONTEXTIDR_EL1],contextidr);
144 write_sysreg_el1(ctxt->sys_regs[AMAIR_EL1], amair);
145 write_sysreg_el1(ctxt->sys_regs[CNTKCTL_EL1], cntkctl);
146 write_sysreg(ctxt->sys_regs[PAR_EL1], par_el1);
147 write_sysreg(ctxt->sys_regs[TPIDR_EL1], tpidr_el1);
149 write_sysreg(ctxt->gp_regs.sp_el1, sp_el1);
150 write_sysreg_el1(ctxt->gp_regs.elr_el1, elr);
151 write_sysreg_el1(ctxt->gp_regs.spsr[KVM_SPSR_EL1],spsr);
154 static void __hyp_text
155 __sysreg_restore_el2_return_state(struct kvm_cpu_context *ctxt)
157 u64 pstate = ctxt->gp_regs.regs.pstate;
158 u64 mode = pstate & PSR_AA32_MODE_MASK;
161 * Safety check to ensure we're setting the CPU up to enter the guest
162 * in a less privileged mode.
164 * If we are attempting a return to EL2 or higher in AArch64 state,
165 * program SPSR_EL2 with M=EL2h and the IL bit set which ensures that
166 * we'll take an illegal exception state exception immediately after
167 * the ERET to the guest. Attempts to return to AArch32 Hyp will
168 * result in an illegal exception return because EL2's execution state
169 * is determined by SCR_EL3.RW.
171 if (!(mode & PSR_MODE32_BIT) && mode >= PSR_MODE_EL2t)
172 pstate = PSR_MODE_EL2h | PSR_IL_BIT;
174 write_sysreg_el2(ctxt->gp_regs.regs.pc, elr);
175 write_sysreg_el2(pstate, spsr);
177 if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN))
178 write_sysreg_s(ctxt->sys_regs[DISR_EL1], SYS_VDISR_EL2);
181 void __hyp_text __sysreg_restore_state_nvhe(struct kvm_cpu_context *ctxt)
183 __sysreg_restore_el1_state(ctxt);
184 __sysreg_restore_common_state(ctxt);
185 __sysreg_restore_user_state(ctxt);
186 __sysreg_restore_el2_return_state(ctxt);
189 void sysreg_restore_host_state_vhe(struct kvm_cpu_context *ctxt)
191 __sysreg_restore_common_state(ctxt);
193 NOKPROBE_SYMBOL(sysreg_restore_host_state_vhe);
195 void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt)
197 __sysreg_restore_common_state(ctxt);
198 __sysreg_restore_el2_return_state(ctxt);
200 NOKPROBE_SYMBOL(sysreg_restore_guest_state_vhe);
202 void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu)
206 if (!vcpu_el1_is_32bit(vcpu))
209 spsr = vcpu->arch.ctxt.gp_regs.spsr;
210 sysreg = vcpu->arch.ctxt.sys_regs;
212 spsr[KVM_SPSR_ABT] = read_sysreg(spsr_abt);
213 spsr[KVM_SPSR_UND] = read_sysreg(spsr_und);
214 spsr[KVM_SPSR_IRQ] = read_sysreg(spsr_irq);
215 spsr[KVM_SPSR_FIQ] = read_sysreg(spsr_fiq);
217 sysreg[DACR32_EL2] = read_sysreg(dacr32_el2);
218 sysreg[IFSR32_EL2] = read_sysreg(ifsr32_el2);
220 if (has_vhe() || vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY)
221 sysreg[DBGVCR32_EL2] = read_sysreg(dbgvcr32_el2);
224 void __hyp_text __sysreg32_restore_state(struct kvm_vcpu *vcpu)
228 if (!vcpu_el1_is_32bit(vcpu))
231 spsr = vcpu->arch.ctxt.gp_regs.spsr;
232 sysreg = vcpu->arch.ctxt.sys_regs;
234 write_sysreg(spsr[KVM_SPSR_ABT], spsr_abt);
235 write_sysreg(spsr[KVM_SPSR_UND], spsr_und);
236 write_sysreg(spsr[KVM_SPSR_IRQ], spsr_irq);
237 write_sysreg(spsr[KVM_SPSR_FIQ], spsr_fiq);
239 write_sysreg(sysreg[DACR32_EL2], dacr32_el2);
240 write_sysreg(sysreg[IFSR32_EL2], ifsr32_el2);
242 if (has_vhe() || vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY)
243 write_sysreg(sysreg[DBGVCR32_EL2], dbgvcr32_el2);
247 * kvm_vcpu_load_sysregs - Load guest system registers to the physical CPU
249 * @vcpu: The VCPU pointer
251 * Load system registers that do not affect the host's execution, for
252 * example EL1 system registers on a VHE system where the host kernel
253 * runs at EL2. This function is called from KVM's vcpu_load() function
254 * and loading system register state early avoids having to load them on
255 * every entry to the VM.
257 void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu)
259 struct kvm_cpu_context *host_ctxt = vcpu->arch.host_cpu_context;
260 struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
265 __sysreg_save_user_state(host_ctxt);
268 * Load guest EL1 and user state
270 * We must restore the 32-bit state before the sysregs, thanks
271 * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72).
273 __sysreg32_restore_state(vcpu);
274 __sysreg_restore_user_state(guest_ctxt);
275 __sysreg_restore_el1_state(guest_ctxt);
277 vcpu->arch.sysregs_loaded_on_cpu = true;
279 activate_traps_vhe_load(vcpu);
283 * kvm_vcpu_put_sysregs - Restore host system registers to the physical CPU
285 * @vcpu: The VCPU pointer
287 * Save guest system registers that do not affect the host's execution, for
288 * example EL1 system registers on a VHE system where the host kernel
289 * runs at EL2. This function is called from KVM's vcpu_put() function
290 * and deferring saving system register state until we're no longer running the
291 * VCPU avoids having to save them on every exit from the VM.
293 void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu)
295 struct kvm_cpu_context *host_ctxt = vcpu->arch.host_cpu_context;
296 struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
301 deactivate_traps_vhe_put();
303 __sysreg_save_el1_state(guest_ctxt);
304 __sysreg_save_user_state(guest_ctxt);
305 __sysreg32_save_state(vcpu);
307 /* Restore host user state */
308 __sysreg_restore_user_state(host_ctxt);
310 vcpu->arch.sysregs_loaded_on_cpu = false;
313 void __hyp_text __kvm_enable_ssbs(void)
318 "mrs %0, sctlr_el2\n"
321 : "=&r" (tmp) : "L" (SCTLR_ELx_DSSBS));