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[MPIDR_EL1] = read_sysreg(vmpidr_el2);
57 ctxt->sys_regs[CSSELR_EL1] = read_sysreg(csselr_el1);
58 ctxt->sys_regs[SCTLR_EL1] = read_sysreg_el1(sctlr);
59 ctxt->sys_regs[ACTLR_EL1] = read_sysreg(actlr_el1);
60 ctxt->sys_regs[CPACR_EL1] = read_sysreg_el1(cpacr);
61 ctxt->sys_regs[TTBR0_EL1] = read_sysreg_el1(ttbr0);
62 ctxt->sys_regs[TTBR1_EL1] = read_sysreg_el1(ttbr1);
63 ctxt->sys_regs[TCR_EL1] = read_sysreg_el1(tcr);
64 ctxt->sys_regs[ESR_EL1] = read_sysreg_el1(esr);
65 ctxt->sys_regs[AFSR0_EL1] = read_sysreg_el1(afsr0);
66 ctxt->sys_regs[AFSR1_EL1] = read_sysreg_el1(afsr1);
67 ctxt->sys_regs[FAR_EL1] = read_sysreg_el1(far);
68 ctxt->sys_regs[MAIR_EL1] = read_sysreg_el1(mair);
69 ctxt->sys_regs[VBAR_EL1] = read_sysreg_el1(vbar);
70 ctxt->sys_regs[CONTEXTIDR_EL1] = read_sysreg_el1(contextidr);
71 ctxt->sys_regs[AMAIR_EL1] = read_sysreg_el1(amair);
72 ctxt->sys_regs[CNTKCTL_EL1] = read_sysreg_el1(cntkctl);
73 ctxt->sys_regs[PAR_EL1] = read_sysreg(par_el1);
74 ctxt->sys_regs[TPIDR_EL1] = read_sysreg(tpidr_el1);
76 ctxt->gp_regs.sp_el1 = read_sysreg(sp_el1);
77 ctxt->gp_regs.elr_el1 = read_sysreg_el1(elr);
78 ctxt->gp_regs.spsr[KVM_SPSR_EL1]= read_sysreg_el1(spsr);
81 static void __hyp_text __sysreg_save_el2_return_state(struct kvm_cpu_context *ctxt)
83 ctxt->gp_regs.regs.pc = read_sysreg_el2(elr);
84 ctxt->gp_regs.regs.pstate = read_sysreg_el2(spsr);
86 if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN))
87 ctxt->sys_regs[DISR_EL1] = read_sysreg_s(SYS_VDISR_EL2);
90 void __hyp_text __sysreg_save_state_nvhe(struct kvm_cpu_context *ctxt)
92 __sysreg_save_el1_state(ctxt);
93 __sysreg_save_common_state(ctxt);
94 __sysreg_save_user_state(ctxt);
95 __sysreg_save_el2_return_state(ctxt);
98 void sysreg_save_host_state_vhe(struct kvm_cpu_context *ctxt)
100 __sysreg_save_common_state(ctxt);
102 NOKPROBE_SYMBOL(sysreg_save_host_state_vhe);
104 void sysreg_save_guest_state_vhe(struct kvm_cpu_context *ctxt)
106 __sysreg_save_common_state(ctxt);
107 __sysreg_save_el2_return_state(ctxt);
109 NOKPROBE_SYMBOL(sysreg_save_guest_state_vhe);
111 static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctxt)
113 write_sysreg(ctxt->sys_regs[MDSCR_EL1], mdscr_el1);
116 * The host arm64 Linux uses sp_el0 to point to 'current' and it must
117 * therefore be saved/restored on every entry/exit to/from the guest.
119 write_sysreg(ctxt->gp_regs.regs.sp, sp_el0);
122 static void __hyp_text __sysreg_restore_user_state(struct kvm_cpu_context *ctxt)
124 write_sysreg(ctxt->sys_regs[TPIDR_EL0], tpidr_el0);
125 write_sysreg(ctxt->sys_regs[TPIDRRO_EL0], tpidrro_el0);
128 static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
130 write_sysreg(ctxt->sys_regs[MPIDR_EL1], vmpidr_el2);
131 write_sysreg(ctxt->sys_regs[CSSELR_EL1], csselr_el1);
132 write_sysreg_el1(ctxt->sys_regs[SCTLR_EL1], sctlr);
133 write_sysreg(ctxt->sys_regs[ACTLR_EL1], actlr_el1);
134 write_sysreg_el1(ctxt->sys_regs[CPACR_EL1], cpacr);
135 write_sysreg_el1(ctxt->sys_regs[TTBR0_EL1], ttbr0);
136 write_sysreg_el1(ctxt->sys_regs[TTBR1_EL1], ttbr1);
137 write_sysreg_el1(ctxt->sys_regs[TCR_EL1], tcr);
138 write_sysreg_el1(ctxt->sys_regs[ESR_EL1], esr);
139 write_sysreg_el1(ctxt->sys_regs[AFSR0_EL1], afsr0);
140 write_sysreg_el1(ctxt->sys_regs[AFSR1_EL1], afsr1);
141 write_sysreg_el1(ctxt->sys_regs[FAR_EL1], far);
142 write_sysreg_el1(ctxt->sys_regs[MAIR_EL1], mair);
143 write_sysreg_el1(ctxt->sys_regs[VBAR_EL1], vbar);
144 write_sysreg_el1(ctxt->sys_regs[CONTEXTIDR_EL1],contextidr);
145 write_sysreg_el1(ctxt->sys_regs[AMAIR_EL1], amair);
146 write_sysreg_el1(ctxt->sys_regs[CNTKCTL_EL1], cntkctl);
147 write_sysreg(ctxt->sys_regs[PAR_EL1], par_el1);
148 write_sysreg(ctxt->sys_regs[TPIDR_EL1], tpidr_el1);
150 write_sysreg(ctxt->gp_regs.sp_el1, sp_el1);
151 write_sysreg_el1(ctxt->gp_regs.elr_el1, elr);
152 write_sysreg_el1(ctxt->gp_regs.spsr[KVM_SPSR_EL1],spsr);
155 static void __hyp_text
156 __sysreg_restore_el2_return_state(struct kvm_cpu_context *ctxt)
158 u64 pstate = ctxt->gp_regs.regs.pstate;
159 u64 mode = pstate & PSR_AA32_MODE_MASK;
162 * Safety check to ensure we're setting the CPU up to enter the guest
163 * in a less privileged mode.
165 * If we are attempting a return to EL2 or higher in AArch64 state,
166 * program SPSR_EL2 with M=EL2h and the IL bit set which ensures that
167 * we'll take an illegal exception state exception immediately after
168 * the ERET to the guest. Attempts to return to AArch32 Hyp will
169 * result in an illegal exception return because EL2's execution state
170 * is determined by SCR_EL3.RW.
172 if (!(mode & PSR_MODE32_BIT) && mode >= PSR_MODE_EL2t)
173 pstate = PSR_MODE_EL2h | PSR_IL_BIT;
175 write_sysreg_el2(ctxt->gp_regs.regs.pc, elr);
176 write_sysreg_el2(pstate, spsr);
178 if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN))
179 write_sysreg_s(ctxt->sys_regs[DISR_EL1], SYS_VDISR_EL2);
182 void __hyp_text __sysreg_restore_state_nvhe(struct kvm_cpu_context *ctxt)
184 __sysreg_restore_el1_state(ctxt);
185 __sysreg_restore_common_state(ctxt);
186 __sysreg_restore_user_state(ctxt);
187 __sysreg_restore_el2_return_state(ctxt);
190 void sysreg_restore_host_state_vhe(struct kvm_cpu_context *ctxt)
192 __sysreg_restore_common_state(ctxt);
194 NOKPROBE_SYMBOL(sysreg_restore_host_state_vhe);
196 void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt)
198 __sysreg_restore_common_state(ctxt);
199 __sysreg_restore_el2_return_state(ctxt);
201 NOKPROBE_SYMBOL(sysreg_restore_guest_state_vhe);
203 void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu)
207 if (!vcpu_el1_is_32bit(vcpu))
210 spsr = vcpu->arch.ctxt.gp_regs.spsr;
211 sysreg = vcpu->arch.ctxt.sys_regs;
213 spsr[KVM_SPSR_ABT] = read_sysreg(spsr_abt);
214 spsr[KVM_SPSR_UND] = read_sysreg(spsr_und);
215 spsr[KVM_SPSR_IRQ] = read_sysreg(spsr_irq);
216 spsr[KVM_SPSR_FIQ] = read_sysreg(spsr_fiq);
218 sysreg[DACR32_EL2] = read_sysreg(dacr32_el2);
219 sysreg[IFSR32_EL2] = read_sysreg(ifsr32_el2);
221 if (has_vhe() || vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY)
222 sysreg[DBGVCR32_EL2] = read_sysreg(dbgvcr32_el2);
225 void __hyp_text __sysreg32_restore_state(struct kvm_vcpu *vcpu)
229 if (!vcpu_el1_is_32bit(vcpu))
232 spsr = vcpu->arch.ctxt.gp_regs.spsr;
233 sysreg = vcpu->arch.ctxt.sys_regs;
235 write_sysreg(spsr[KVM_SPSR_ABT], spsr_abt);
236 write_sysreg(spsr[KVM_SPSR_UND], spsr_und);
237 write_sysreg(spsr[KVM_SPSR_IRQ], spsr_irq);
238 write_sysreg(spsr[KVM_SPSR_FIQ], spsr_fiq);
240 write_sysreg(sysreg[DACR32_EL2], dacr32_el2);
241 write_sysreg(sysreg[IFSR32_EL2], ifsr32_el2);
243 if (has_vhe() || vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY)
244 write_sysreg(sysreg[DBGVCR32_EL2], dbgvcr32_el2);
248 * kvm_vcpu_load_sysregs - Load guest system registers to the physical CPU
250 * @vcpu: The VCPU pointer
252 * Load system registers that do not affect the host's execution, for
253 * example EL1 system registers on a VHE system where the host kernel
254 * runs at EL2. This function is called from KVM's vcpu_load() function
255 * and loading system register state early avoids having to load them on
256 * every entry to the VM.
258 void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu)
260 struct kvm_cpu_context *host_ctxt = vcpu->arch.host_cpu_context;
261 struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
266 __sysreg_save_user_state(host_ctxt);
269 * Load guest EL1 and user state
271 * We must restore the 32-bit state before the sysregs, thanks
272 * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72).
274 __sysreg32_restore_state(vcpu);
275 __sysreg_restore_user_state(guest_ctxt);
276 __sysreg_restore_el1_state(guest_ctxt);
278 vcpu->arch.sysregs_loaded_on_cpu = true;
280 activate_traps_vhe_load(vcpu);
284 * kvm_vcpu_put_sysregs - Restore host system registers to the physical CPU
286 * @vcpu: The VCPU pointer
288 * Save guest system registers that do not affect the host's execution, for
289 * example EL1 system registers on a VHE system where the host kernel
290 * runs at EL2. This function is called from KVM's vcpu_put() function
291 * and deferring saving system register state until we're no longer running the
292 * VCPU avoids having to save them on every exit from the VM.
294 void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu)
296 struct kvm_cpu_context *host_ctxt = vcpu->arch.host_cpu_context;
297 struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
302 deactivate_traps_vhe_put();
304 __sysreg_save_el1_state(guest_ctxt);
305 __sysreg_save_user_state(guest_ctxt);
306 __sysreg32_save_state(vcpu);
308 /* Restore host user state */
309 __sysreg_restore_user_state(host_ctxt);
311 vcpu->arch.sysregs_loaded_on_cpu = false;
314 void __hyp_text __kvm_enable_ssbs(void)
319 "mrs %0, sctlr_el2\n"
322 : "=&r" (tmp) : "L" (SCTLR_ELx_DSSBS));