2 * Copyright (C) 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/types.h>
19 #include <linux/jump_label.h>
21 #include <asm/kvm_asm.h>
22 #include <asm/kvm_emulate.h>
23 #include <asm/kvm_hyp.h>
24 #include <asm/fpsimd.h>
25 #include <asm/debug-monitors.h>
27 static bool __hyp_text __fpsimd_enabled_nvhe(void)
29 return !(read_sysreg(cptr_el2) & CPTR_EL2_TFP);
32 static bool __hyp_text __fpsimd_enabled_vhe(void)
34 return !!(read_sysreg(cpacr_el1) & CPACR_EL1_FPEN);
37 static hyp_alternate_select(__fpsimd_is_enabled,
38 __fpsimd_enabled_nvhe, __fpsimd_enabled_vhe,
39 ARM64_HAS_VIRT_HOST_EXTN);
41 bool __hyp_text __fpsimd_enabled(void)
43 return __fpsimd_is_enabled()();
46 static void __hyp_text __activate_traps_vhe(void)
50 val = read_sysreg(cpacr_el1);
52 val &= ~(CPACR_EL1_FPEN | CPACR_EL1_ZEN);
53 write_sysreg(val, cpacr_el1);
55 write_sysreg(__kvm_hyp_vector, vbar_el1);
58 static void __hyp_text __activate_traps_nvhe(void)
62 val = CPTR_EL2_DEFAULT;
63 val |= CPTR_EL2_TTA | CPTR_EL2_TFP | CPTR_EL2_TZ;
64 write_sysreg(val, cptr_el2);
67 static hyp_alternate_select(__activate_traps_arch,
68 __activate_traps_nvhe, __activate_traps_vhe,
69 ARM64_HAS_VIRT_HOST_EXTN);
71 static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu)
76 * We are about to set CPTR_EL2.TFP to trap all floating point
77 * register accesses to EL2, however, the ARM ARM clearly states that
78 * traps are only taken to EL2 if the operation would not otherwise
79 * trap to EL1. Therefore, always make sure that for 32-bit guests,
80 * we set FPEXC.EN to prevent traps to EL1, when setting the TFP bit.
81 * If FP/ASIMD is not implemented, FPEXC is UNDEFINED and any access to
82 * it will cause an exception.
84 val = vcpu->arch.hcr_el2;
86 if (!(val & HCR_RW) && system_supports_fpsimd()) {
87 write_sysreg(1 << 30, fpexc32_el2);
91 if (val & HCR_RW) /* for AArch64 only: */
92 val |= HCR_TID3; /* TID3: trap feature register accesses */
94 write_sysreg(val, hcr_el2);
96 /* Trap on AArch32 cp15 c15 accesses (EL1 or EL0) */
97 write_sysreg(1 << 15, hstr_el2);
99 * Make sure we trap PMU access from EL0 to EL2. Also sanitize
100 * PMSELR_EL0 to make sure it never contains the cycle
101 * counter, which could make a PMXEVCNTR_EL0 access UNDEF at
102 * EL1 instead of being trapped to EL2.
104 write_sysreg(0, pmselr_el0);
105 write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0);
106 write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2);
107 __activate_traps_arch()();
110 static void __hyp_text __deactivate_traps_vhe(void)
112 extern char vectors[]; /* kernel exception vectors */
113 u64 mdcr_el2 = read_sysreg(mdcr_el2);
115 mdcr_el2 &= MDCR_EL2_HPMN_MASK |
116 MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT |
119 write_sysreg(mdcr_el2, mdcr_el2);
120 write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);
121 write_sysreg(CPACR_EL1_DEFAULT, cpacr_el1);
122 write_sysreg(vectors, vbar_el1);
125 static void __hyp_text __deactivate_traps_nvhe(void)
127 u64 mdcr_el2 = read_sysreg(mdcr_el2);
129 mdcr_el2 &= MDCR_EL2_HPMN_MASK;
130 mdcr_el2 |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT;
132 write_sysreg(mdcr_el2, mdcr_el2);
133 write_sysreg(HCR_RW, hcr_el2);
134 write_sysreg(CPTR_EL2_DEFAULT, cptr_el2);
137 static hyp_alternate_select(__deactivate_traps_arch,
138 __deactivate_traps_nvhe, __deactivate_traps_vhe,
139 ARM64_HAS_VIRT_HOST_EXTN);
141 static void __hyp_text __deactivate_traps(struct kvm_vcpu *vcpu)
144 * If we pended a virtual abort, preserve it until it gets
145 * cleared. See D1.14.3 (Virtual Interrupts) for details, but
146 * the crucial bit is "On taking a vSError interrupt,
147 * HCR_EL2.VSE is cleared to 0."
149 if (vcpu->arch.hcr_el2 & HCR_VSE)
150 vcpu->arch.hcr_el2 = read_sysreg(hcr_el2);
152 __deactivate_traps_arch()();
153 write_sysreg(0, hstr_el2);
154 write_sysreg(0, pmuserenr_el0);
157 static void __hyp_text __activate_vm(struct kvm_vcpu *vcpu)
159 struct kvm *kvm = kern_hyp_va(vcpu->kvm);
160 write_sysreg(kvm->arch.vttbr, vttbr_el2);
163 static void __hyp_text __deactivate_vm(struct kvm_vcpu *vcpu)
165 write_sysreg(0, vttbr_el2);
168 static void __hyp_text __vgic_save_state(struct kvm_vcpu *vcpu)
170 if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
171 __vgic_v3_save_state(vcpu);
173 __vgic_v2_save_state(vcpu);
175 write_sysreg(read_sysreg(hcr_el2) & ~HCR_INT_OVERRIDE, hcr_el2);
178 static void __hyp_text __vgic_restore_state(struct kvm_vcpu *vcpu)
182 val = read_sysreg(hcr_el2);
183 val |= HCR_INT_OVERRIDE;
184 val |= vcpu->arch.irq_lines;
185 write_sysreg(val, hcr_el2);
187 if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
188 __vgic_v3_restore_state(vcpu);
190 __vgic_v2_restore_state(vcpu);
193 static bool __hyp_text __true_value(void)
198 static bool __hyp_text __false_value(void)
203 static hyp_alternate_select(__check_arm_834220,
204 __false_value, __true_value,
205 ARM64_WORKAROUND_834220);
207 static bool __hyp_text __translate_far_to_hpfar(u64 far, u64 *hpfar)
212 * Resolve the IPA the hard way using the guest VA.
214 * Stage-1 translation already validated the memory access
215 * rights. As such, we can use the EL1 translation regime, and
216 * don't have to distinguish between EL0 and EL1 access.
218 * We do need to save/restore PAR_EL1 though, as we haven't
219 * saved the guest context yet, and we may return early...
221 par = read_sysreg(par_el1);
222 asm volatile("at s1e1r, %0" : : "r" (far));
225 tmp = read_sysreg(par_el1);
226 write_sysreg(par, par_el1);
228 if (unlikely(tmp & 1))
229 return false; /* Translation failed, back to guest */
231 /* Convert PAR to HPFAR format */
232 *hpfar = ((tmp >> 12) & ((1UL << 36) - 1)) << 4;
236 static bool __hyp_text __populate_fault_info(struct kvm_vcpu *vcpu)
238 u64 esr = read_sysreg_el2(esr);
239 u8 ec = ESR_ELx_EC(esr);
242 vcpu->arch.fault.esr_el2 = esr;
244 if (ec != ESR_ELx_EC_DABT_LOW && ec != ESR_ELx_EC_IABT_LOW)
247 far = read_sysreg_el2(far);
250 * The HPFAR can be invalid if the stage 2 fault did not
251 * happen during a stage 1 page table walk (the ESR_EL2.S1PTW
252 * bit is clear) and one of the two following cases are true:
253 * 1. The fault was due to a permission fault
254 * 2. The processor carries errata 834220
256 * Therefore, for all non S1PTW faults where we either have a
257 * permission fault or the errata workaround is enabled, we
258 * resolve the IPA using the AT instruction.
260 if (!(esr & ESR_ELx_S1PTW) &&
261 (__check_arm_834220()() || (esr & ESR_ELx_FSC_TYPE) == FSC_PERM)) {
262 if (!__translate_far_to_hpfar(far, &hpfar))
265 hpfar = read_sysreg(hpfar_el2);
268 vcpu->arch.fault.far_el2 = far;
269 vcpu->arch.fault.hpfar_el2 = hpfar;
273 /* Skip an instruction which has been emulated. Returns true if
274 * execution can continue or false if we need to exit hyp mode because
275 * single-step was in effect.
277 static bool __hyp_text __skip_instr(struct kvm_vcpu *vcpu)
279 *vcpu_pc(vcpu) = read_sysreg_el2(elr);
281 if (vcpu_mode_is_32bit(vcpu)) {
282 vcpu->arch.ctxt.gp_regs.regs.pstate = read_sysreg_el2(spsr);
283 kvm_skip_instr32(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
284 write_sysreg_el2(vcpu->arch.ctxt.gp_regs.regs.pstate, spsr);
289 write_sysreg_el2(*vcpu_pc(vcpu), elr);
291 if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) {
292 vcpu->arch.fault.esr_el2 =
293 (ESR_ELx_EC_SOFTSTP_LOW << ESR_ELx_EC_SHIFT) | 0x22;
300 int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu)
302 struct kvm_cpu_context *host_ctxt;
303 struct kvm_cpu_context *guest_ctxt;
307 vcpu = kern_hyp_va(vcpu);
308 write_sysreg(vcpu, tpidr_el2);
310 host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
311 guest_ctxt = &vcpu->arch.ctxt;
313 __sysreg_save_host_state(host_ctxt);
314 __debug_cond_save_host_state(vcpu);
316 __activate_traps(vcpu);
319 __vgic_restore_state(vcpu);
320 __timer_enable_traps(vcpu);
323 * We must restore the 32-bit state before the sysregs, thanks
324 * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72).
326 __sysreg32_restore_state(vcpu);
327 __sysreg_restore_guest_state(guest_ctxt);
328 __debug_restore_state(vcpu, kern_hyp_va(vcpu->arch.debug_ptr), guest_ctxt);
330 /* Jump in the fire! */
332 exit_code = __guest_enter(vcpu, host_ctxt);
333 /* And we're baaack! */
336 * We're using the raw exception code in order to only process
337 * the trap if no SError is pending. We will come back to the
338 * same PC once the SError has been injected, and replay the
339 * trapping instruction.
341 if (exit_code == ARM_EXCEPTION_TRAP && !__populate_fault_info(vcpu))
344 if (static_branch_unlikely(&vgic_v2_cpuif_trap) &&
345 exit_code == ARM_EXCEPTION_TRAP) {
348 valid = kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_DABT_LOW &&
349 kvm_vcpu_trap_get_fault_type(vcpu) == FSC_FAULT &&
350 kvm_vcpu_dabt_isvalid(vcpu) &&
351 !kvm_vcpu_dabt_isextabt(vcpu) &&
352 !kvm_vcpu_dabt_iss1tw(vcpu);
355 int ret = __vgic_v2_perform_cpuif_access(vcpu);
358 if (__skip_instr(vcpu))
361 exit_code = ARM_EXCEPTION_TRAP;
365 /* Promote an illegal access to an
366 * SError. If we would be returning
367 * due to single-step clear the SS
368 * bit so handle_exit knows what to
369 * do after dealing with the error.
371 if (!__skip_instr(vcpu))
372 *vcpu_cpsr(vcpu) &= ~DBG_SPSR_SS;
373 exit_code = ARM_EXCEPTION_EL1_SERROR;
376 /* 0 falls through to be handler out of EL2 */
380 if (static_branch_unlikely(&vgic_v3_cpuif_trap) &&
381 exit_code == ARM_EXCEPTION_TRAP &&
382 (kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_SYS64 ||
383 kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_CP15_32)) {
384 int ret = __vgic_v3_perform_cpuif_access(vcpu);
387 if (__skip_instr(vcpu))
390 exit_code = ARM_EXCEPTION_TRAP;
393 /* 0 falls through to be handled out of EL2 */
396 fp_enabled = __fpsimd_enabled();
398 __sysreg_save_guest_state(guest_ctxt);
399 __sysreg32_save_state(vcpu);
400 __timer_disable_traps(vcpu);
401 __vgic_save_state(vcpu);
403 __deactivate_traps(vcpu);
404 __deactivate_vm(vcpu);
406 __sysreg_restore_host_state(host_ctxt);
409 __fpsimd_save_state(&guest_ctxt->gp_regs.fp_regs);
410 __fpsimd_restore_state(&host_ctxt->gp_regs.fp_regs);
413 __debug_save_state(vcpu, kern_hyp_va(vcpu->arch.debug_ptr), guest_ctxt);
415 * This must come after restoring the host sysregs, since a non-VHE
416 * system may enable SPE here and make use of the TTBRs.
418 __debug_cond_restore_host_state(vcpu);
423 static const char __hyp_panic_string[] = "HYP panic:\nPS:%08llx PC:%016llx ESR:%08llx\nFAR:%016llx HPFAR:%016llx PAR:%016llx\nVCPU:%p\n";
425 static void __hyp_text __hyp_call_panic_nvhe(u64 spsr, u64 elr, u64 par)
427 unsigned long str_va;
430 * Force the panic string to be loaded from the literal pool,
431 * making sure it is a kernel address and not a PC-relative
434 asm volatile("ldr %0, =__hyp_panic_string" : "=r" (str_va));
436 __hyp_do_panic(str_va,
438 read_sysreg(esr_el2), read_sysreg_el2(far),
439 read_sysreg(hpfar_el2), par,
440 (void *)read_sysreg(tpidr_el2));
443 static void __hyp_text __hyp_call_panic_vhe(u64 spsr, u64 elr, u64 par)
445 panic(__hyp_panic_string,
447 read_sysreg_el2(esr), read_sysreg_el2(far),
448 read_sysreg(hpfar_el2), par,
449 (void *)read_sysreg(tpidr_el2));
452 static hyp_alternate_select(__hyp_call_panic,
453 __hyp_call_panic_nvhe, __hyp_call_panic_vhe,
454 ARM64_HAS_VIRT_HOST_EXTN);
456 void __hyp_text __noreturn __hyp_panic(void)
458 u64 spsr = read_sysreg_el2(spsr);
459 u64 elr = read_sysreg_el2(elr);
460 u64 par = read_sysreg(par_el1);
462 if (read_sysreg(vttbr_el2)) {
463 struct kvm_vcpu *vcpu;
464 struct kvm_cpu_context *host_ctxt;
466 vcpu = (struct kvm_vcpu *)read_sysreg(tpidr_el2);
467 host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
468 __timer_disable_traps(vcpu);
469 __deactivate_traps(vcpu);
470 __deactivate_vm(vcpu);
471 __sysreg_restore_host_state(host_ctxt);
474 /* Call panic for real */
475 __hyp_call_panic()(spsr, elr, par);