diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/switch.c')
| -rw-r--r-- | arch/arm64/kvm/hyp/switch.c | 636 |
1 files changed, 0 insertions, 636 deletions
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c deleted file mode 100644 index b0b1478094b4..000000000000 --- a/arch/arm64/kvm/hyp/switch.c +++ /dev/null @@ -1,636 +0,0 @@ -/* - * Copyright (C) 2015 - ARM Ltd - * Author: Marc Zyngier <marc.zyngier@arm.com> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program. If not, see <http://www.gnu.org/licenses/>. - */ - -#include <linux/arm-smccc.h> -#include <linux/types.h> -#include <linux/jump_label.h> -#include <uapi/linux/psci.h> - -#include <kvm/arm_psci.h> - -#include <asm/cpufeature.h> -#include <asm/kvm_asm.h> -#include <asm/kvm_emulate.h> -#include <asm/kvm_host.h> -#include <asm/kvm_hyp.h> -#include <asm/kvm_mmu.h> -#include <asm/fpsimd.h> -#include <asm/debug-monitors.h> -#include <asm/processor.h> -#include <asm/thread_info.h> - -/* Check whether the FP regs were dirtied while in the host-side run loop: */ -static bool __hyp_text update_fp_enabled(struct kvm_vcpu *vcpu) -{ - if (vcpu->arch.host_thread_info->flags & _TIF_FOREIGN_FPSTATE) - vcpu->arch.flags &= ~(KVM_ARM64_FP_ENABLED | - KVM_ARM64_FP_HOST); - - return !!(vcpu->arch.flags & KVM_ARM64_FP_ENABLED); -} - -/* Save the 32-bit only FPSIMD system register state */ -static void __hyp_text __fpsimd_save_fpexc32(struct kvm_vcpu *vcpu) -{ - if (!vcpu_el1_is_32bit(vcpu)) - return; - - vcpu->arch.ctxt.sys_regs[FPEXC32_EL2] = read_sysreg(fpexc32_el2); -} - -static void __hyp_text __activate_traps_fpsimd32(struct kvm_vcpu *vcpu) -{ - /* - * We are about to set CPTR_EL2.TFP to trap all floating point - * register accesses to EL2, however, the ARM ARM clearly states that - * traps are only taken to EL2 if the operation would not otherwise - * trap to EL1. Therefore, always make sure that for 32-bit guests, - * we set FPEXC.EN to prevent traps to EL1, when setting the TFP bit. - * If FP/ASIMD is not implemented, FPEXC is UNDEFINED and any access to - * it will cause an exception. - */ - if (vcpu_el1_is_32bit(vcpu) && system_supports_fpsimd()) { - write_sysreg(1 << 30, fpexc32_el2); - isb(); - } -} - -static void __hyp_text __activate_traps_common(struct kvm_vcpu *vcpu) -{ - /* Trap on AArch32 cp15 c15 (impdef sysregs) accesses (EL1 or EL0) */ - write_sysreg(1 << 15, hstr_el2); - - /* - * Make sure we trap PMU access from EL0 to EL2. Also sanitize - * PMSELR_EL0 to make sure it never contains the cycle - * counter, which could make a PMXEVCNTR_EL0 access UNDEF at - * EL1 instead of being trapped to EL2. - */ - write_sysreg(0, pmselr_el0); - write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0); - write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); -} - -static void __hyp_text __deactivate_traps_common(void) -{ - write_sysreg(0, hstr_el2); - write_sysreg(0, pmuserenr_el0); -} - -static void activate_traps_vhe(struct kvm_vcpu *vcpu) -{ - u64 val; - - val = read_sysreg(cpacr_el1); - val |= CPACR_EL1_TTA; - val &= ~CPACR_EL1_ZEN; - if (!update_fp_enabled(vcpu)) { - val &= ~CPACR_EL1_FPEN; - __activate_traps_fpsimd32(vcpu); - } - - write_sysreg(val, cpacr_el1); - - write_sysreg(kvm_get_hyp_vector(), vbar_el1); -} - -static void __hyp_text __activate_traps_nvhe(struct kvm_vcpu *vcpu) -{ - u64 val; - - __activate_traps_common(vcpu); - - val = CPTR_EL2_DEFAULT; - val |= CPTR_EL2_TTA | CPTR_EL2_TZ; - if (!update_fp_enabled(vcpu)) { - val |= CPTR_EL2_TFP; - __activate_traps_fpsimd32(vcpu); - } - - write_sysreg(val, cptr_el2); -} - -static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu) -{ - u64 hcr = vcpu->arch.hcr_el2; - - write_sysreg(hcr, hcr_el2); - - if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN) && (hcr & HCR_VSE)) - write_sysreg_s(vcpu->arch.vsesr_el2, SYS_VSESR_EL2); - - if (has_vhe()) - activate_traps_vhe(vcpu); - else - __activate_traps_nvhe(vcpu); -} - -static void deactivate_traps_vhe(void) -{ - extern char vectors[]; /* kernel exception vectors */ - write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2); - - /* - * ARM erratum 1165522 requires the actual execution of the above - * before we can switch to the EL2/EL0 translation regime used by - * the host. - */ - asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_1165522)); - - write_sysreg(CPACR_EL1_DEFAULT, cpacr_el1); - write_sysreg(vectors, vbar_el1); -} - -static void __hyp_text __deactivate_traps_nvhe(void) -{ - u64 mdcr_el2 = read_sysreg(mdcr_el2); - - __deactivate_traps_common(); - - mdcr_el2 &= MDCR_EL2_HPMN_MASK; - mdcr_el2 |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT; - - write_sysreg(mdcr_el2, mdcr_el2); - write_sysreg(HCR_HOST_NVHE_FLAGS, hcr_el2); - write_sysreg(CPTR_EL2_DEFAULT, cptr_el2); -} - -static void __hyp_text __deactivate_traps(struct kvm_vcpu *vcpu) -{ - /* - * If we pended a virtual abort, preserve it until it gets - * cleared. See D1.14.3 (Virtual Interrupts) for details, but - * the crucial bit is "On taking a vSError interrupt, - * HCR_EL2.VSE is cleared to 0." - */ - if (vcpu->arch.hcr_el2 & HCR_VSE) - vcpu->arch.hcr_el2 = read_sysreg(hcr_el2); - - if (has_vhe()) - deactivate_traps_vhe(); - else - __deactivate_traps_nvhe(); -} - -void activate_traps_vhe_load(struct kvm_vcpu *vcpu) -{ - __activate_traps_common(vcpu); -} - -void deactivate_traps_vhe_put(void) -{ - u64 mdcr_el2 = read_sysreg(mdcr_el2); - - mdcr_el2 &= MDCR_EL2_HPMN_MASK | - MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT | - MDCR_EL2_TPMS; - - write_sysreg(mdcr_el2, mdcr_el2); - - __deactivate_traps_common(); -} - -static void __hyp_text __activate_vm(struct kvm *kvm) -{ - __load_guest_stage2(kvm); -} - -static void __hyp_text __deactivate_vm(struct kvm_vcpu *vcpu) -{ - write_sysreg(0, vttbr_el2); -} - -/* Save VGICv3 state on non-VHE systems */ -static void __hyp_text __hyp_vgic_save_state(struct kvm_vcpu *vcpu) -{ - if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) { - __vgic_v3_save_state(vcpu); - __vgic_v3_deactivate_traps(vcpu); - } -} - -/* Restore VGICv3 state on non_VEH systems */ -static void __hyp_text __hyp_vgic_restore_state(struct kvm_vcpu *vcpu) -{ - if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) { - __vgic_v3_activate_traps(vcpu); - __vgic_v3_restore_state(vcpu); - } -} - -static bool __hyp_text __true_value(void) -{ - return true; -} - -static bool __hyp_text __false_value(void) -{ - return false; -} - -static hyp_alternate_select(__check_arm_834220, - __false_value, __true_value, - ARM64_WORKAROUND_834220); - -static bool __hyp_text __translate_far_to_hpfar(u64 far, u64 *hpfar) -{ - u64 par, tmp; - - /* - * Resolve the IPA the hard way using the guest VA. - * - * Stage-1 translation already validated the memory access - * rights. As such, we can use the EL1 translation regime, and - * don't have to distinguish between EL0 and EL1 access. - * - * We do need to save/restore PAR_EL1 though, as we haven't - * saved the guest context yet, and we may return early... - */ - par = read_sysreg(par_el1); - asm volatile("at s1e1r, %0" : : "r" (far)); - isb(); - - tmp = read_sysreg(par_el1); - write_sysreg(par, par_el1); - - if (unlikely(tmp & 1)) - return false; /* Translation failed, back to guest */ - - /* Convert PAR to HPFAR format */ - *hpfar = PAR_TO_HPFAR(tmp); - return true; -} - -static bool __hyp_text __populate_fault_info(struct kvm_vcpu *vcpu) -{ - u8 ec; - u64 esr; - u64 hpfar, far; - - esr = vcpu->arch.fault.esr_el2; - ec = ESR_ELx_EC(esr); - - if (ec != ESR_ELx_EC_DABT_LOW && ec != ESR_ELx_EC_IABT_LOW) - return true; - - far = read_sysreg_el2(far); - - /* - * The HPFAR can be invalid if the stage 2 fault did not - * happen during a stage 1 page table walk (the ESR_EL2.S1PTW - * bit is clear) and one of the two following cases are true: - * 1. The fault was due to a permission fault - * 2. The processor carries errata 834220 - * - * Therefore, for all non S1PTW faults where we either have a - * permission fault or the errata workaround is enabled, we - * resolve the IPA using the AT instruction. - */ - if (!(esr & ESR_ELx_S1PTW) && - (__check_arm_834220()() || (esr & ESR_ELx_FSC_TYPE) == FSC_PERM)) { - if (!__translate_far_to_hpfar(far, &hpfar)) - return false; - } else { - hpfar = read_sysreg(hpfar_el2); - } - - vcpu->arch.fault.far_el2 = far; - vcpu->arch.fault.hpfar_el2 = hpfar; - return true; -} - -static bool __hyp_text __hyp_switch_fpsimd(struct kvm_vcpu *vcpu) -{ - struct user_fpsimd_state *host_fpsimd = vcpu->arch.host_fpsimd_state; - - if (has_vhe()) - write_sysreg(read_sysreg(cpacr_el1) | CPACR_EL1_FPEN, - cpacr_el1); - else - write_sysreg(read_sysreg(cptr_el2) & ~(u64)CPTR_EL2_TFP, - cptr_el2); - - isb(); - - if (vcpu->arch.flags & KVM_ARM64_FP_HOST) { - /* - * In the SVE case, VHE is assumed: it is enforced by - * Kconfig and kvm_arch_init(). - */ - if (system_supports_sve() && - (vcpu->arch.flags & KVM_ARM64_HOST_SVE_IN_USE)) { - struct thread_struct *thread = container_of( - host_fpsimd, - struct thread_struct, uw.fpsimd_state); - - sve_save_state(sve_pffr(thread), &host_fpsimd->fpsr); - } else { - __fpsimd_save_state(host_fpsimd); - } - - vcpu->arch.flags &= ~KVM_ARM64_FP_HOST; - } - - __fpsimd_restore_state(&vcpu->arch.ctxt.gp_regs.fp_regs); - - /* Skip restoring fpexc32 for AArch64 guests */ - if (!(read_sysreg(hcr_el2) & HCR_RW)) - write_sysreg(vcpu->arch.ctxt.sys_regs[FPEXC32_EL2], - fpexc32_el2); - - vcpu->arch.flags |= KVM_ARM64_FP_ENABLED; - - return true; -} - -/* - * Return true when we were able to fixup the guest exit and should return to - * the guest, false when we should restore the host state and return to the - * main run loop. - */ -static bool __hyp_text fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code) -{ - if (ARM_EXCEPTION_CODE(*exit_code) != ARM_EXCEPTION_IRQ) - vcpu->arch.fault.esr_el2 = read_sysreg_el2(esr); - - /* - * We're using the raw exception code in order to only process - * the trap if no SError is pending. We will come back to the - * same PC once the SError has been injected, and replay the - * trapping instruction. - */ - if (*exit_code != ARM_EXCEPTION_TRAP) - goto exit; - - /* - * We trap the first access to the FP/SIMD to save the host context - * and restore the guest context lazily. - * If FP/SIMD is not implemented, handle the trap and inject an - * undefined instruction exception to the guest. - */ - if (system_supports_fpsimd() && - kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_FP_ASIMD) - return __hyp_switch_fpsimd(vcpu); - - if (!__populate_fault_info(vcpu)) - return true; - - if (static_branch_unlikely(&vgic_v2_cpuif_trap)) { - bool valid; - - valid = kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_DABT_LOW && - kvm_vcpu_trap_get_fault_type(vcpu) == FSC_FAULT && - kvm_vcpu_dabt_isvalid(vcpu) && - !kvm_vcpu_dabt_isextabt(vcpu) && - !kvm_vcpu_dabt_iss1tw(vcpu); - - if (valid) { - int ret = __vgic_v2_perform_cpuif_access(vcpu); - - if (ret == 1) - return true; - - /* Promote an illegal access to an SError.*/ - if (ret == -1) - *exit_code = ARM_EXCEPTION_EL1_SERROR; - - goto exit; - } - } - - if (static_branch_unlikely(&vgic_v3_cpuif_trap) && - (kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_SYS64 || - kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_CP15_32)) { - int ret = __vgic_v3_perform_cpuif_access(vcpu); - - if (ret == 1) - return true; - } - -exit: - /* Return to the host kernel and handle the exit */ - return false; -} - -static inline bool __hyp_text __needs_ssbd_off(struct kvm_vcpu *vcpu) -{ - if (!cpus_have_const_cap(ARM64_SSBD)) - return false; - - return !(vcpu->arch.workaround_flags & VCPU_WORKAROUND_2_FLAG); -} - -static void __hyp_text __set_guest_arch_workaround_state(struct kvm_vcpu *vcpu) -{ -#ifdef CONFIG_ARM64_SSBD - /* - * The host runs with the workaround always present. If the - * guest wants it disabled, so be it... - */ - if (__needs_ssbd_off(vcpu) && - __hyp_this_cpu_read(arm64_ssbd_callback_required)) - arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_2, 0, NULL); -#endif -} - -static void __hyp_text __set_host_arch_workaround_state(struct kvm_vcpu *vcpu) -{ -#ifdef CONFIG_ARM64_SSBD - /* - * If the guest has disabled the workaround, bring it back on. - */ - if (__needs_ssbd_off(vcpu) && - __hyp_this_cpu_read(arm64_ssbd_callback_required)) - arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_2, 1, NULL); -#endif -} - -/* Switch to the guest for VHE systems running in EL2 */ -int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) -{ - struct kvm_cpu_context *host_ctxt; - struct kvm_cpu_context *guest_ctxt; - u64 exit_code; - - host_ctxt = vcpu->arch.host_cpu_context; - host_ctxt->__hyp_running_vcpu = vcpu; - guest_ctxt = &vcpu->arch.ctxt; - - sysreg_save_host_state_vhe(host_ctxt); - - /* - * ARM erratum 1165522 requires us to configure both stage 1 and - * stage 2 translation for the guest context before we clear - * HCR_EL2.TGE. - * - * We have already configured the guest's stage 1 translation in - * kvm_vcpu_load_sysregs above. We must now call __activate_vm - * before __activate_traps, because __activate_vm configures - * stage 2 translation, and __activate_traps clear HCR_EL2.TGE - * (among other things). - */ - __activate_vm(vcpu->kvm); - __activate_traps(vcpu); - - sysreg_restore_guest_state_vhe(guest_ctxt); - __debug_switch_to_guest(vcpu); - - __set_guest_arch_workaround_state(vcpu); - - do { - /* Jump in the fire! */ - exit_code = __guest_enter(vcpu, host_ctxt); - - /* And we're baaack! */ - } while (fixup_guest_exit(vcpu, &exit_code)); - - __set_host_arch_workaround_state(vcpu); - - sysreg_save_guest_state_vhe(guest_ctxt); - - __deactivate_traps(vcpu); - - sysreg_restore_host_state_vhe(host_ctxt); - - if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) - __fpsimd_save_fpexc32(vcpu); - - __debug_switch_to_host(vcpu); - - return exit_code; -} - -/* Switch to the guest for legacy non-VHE systems */ -int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu) -{ - struct kvm_cpu_context *host_ctxt; - struct kvm_cpu_context *guest_ctxt; - u64 exit_code; - - vcpu = kern_hyp_va(vcpu); - - host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); - host_ctxt->__hyp_running_vcpu = vcpu; - guest_ctxt = &vcpu->arch.ctxt; - - __sysreg_save_state_nvhe(host_ctxt); - - __activate_vm(kern_hyp_va(vcpu->kvm)); - __activate_traps(vcpu); - - __hyp_vgic_restore_state(vcpu); - __timer_enable_traps(vcpu); - - /* - * We must restore the 32-bit state before the sysregs, thanks - * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72). - */ - __sysreg32_restore_state(vcpu); - __sysreg_restore_state_nvhe(guest_ctxt); - __debug_switch_to_guest(vcpu); - - __set_guest_arch_workaround_state(vcpu); - - do { - /* Jump in the fire! */ - exit_code = __guest_enter(vcpu, host_ctxt); - - /* And we're baaack! */ - } while (fixup_guest_exit(vcpu, &exit_code)); - - __set_host_arch_workaround_state(vcpu); - - __sysreg_save_state_nvhe(guest_ctxt); - __sysreg32_save_state(vcpu); - __timer_disable_traps(vcpu); - __hyp_vgic_save_state(vcpu); - - __deactivate_traps(vcpu); - __deactivate_vm(vcpu); - - __sysreg_restore_state_nvhe(host_ctxt); - - if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) - __fpsimd_save_fpexc32(vcpu); - - /* - * This must come after restoring the host sysregs, since a non-VHE - * system may enable SPE here and make use of the TTBRs. - */ - __debug_switch_to_host(vcpu); - - return exit_code; -} - -static const char __hyp_panic_string[] = "HYP panic:\nPS:%08llx PC:%016llx ESR:%08llx\nFAR:%016llx HPFAR:%016llx PAR:%016llx\nVCPU:%p\n"; - -static void __hyp_text __hyp_call_panic_nvhe(u64 spsr, u64 elr, u64 par, - struct kvm_cpu_context *__host_ctxt) -{ - struct kvm_vcpu *vcpu; - unsigned long str_va; - - vcpu = __host_ctxt->__hyp_running_vcpu; - - if (read_sysreg(vttbr_el2)) { - __timer_disable_traps(vcpu); - __deactivate_traps(vcpu); - __deactivate_vm(vcpu); - __sysreg_restore_state_nvhe(__host_ctxt); - } - - /* - * Force the panic string to be loaded from the literal pool, - * making sure it is a kernel address and not a PC-relative - * reference. - */ - asm volatile("ldr %0, =__hyp_panic_string" : "=r" (str_va)); - - __hyp_do_panic(str_va, - spsr, elr, - read_sysreg(esr_el2), read_sysreg_el2(far), - read_sysreg(hpfar_el2), par, vcpu); -} - -static void __hyp_call_panic_vhe(u64 spsr, u64 elr, u64 par, - struct kvm_cpu_context *host_ctxt) -{ - struct kvm_vcpu *vcpu; - vcpu = host_ctxt->__hyp_running_vcpu; - - __deactivate_traps(vcpu); - sysreg_restore_host_state_vhe(host_ctxt); - - panic(__hyp_panic_string, - spsr, elr, - read_sysreg_el2(esr), read_sysreg_el2(far), - read_sysreg(hpfar_el2), par, vcpu); -} - -void __hyp_text __noreturn hyp_panic(struct kvm_cpu_context *host_ctxt) -{ - u64 spsr = read_sysreg_el2(spsr); - u64 elr = read_sysreg_el2(elr); - u64 par = read_sysreg(par_el1); - - if (!has_vhe()) - __hyp_call_panic_nvhe(spsr, elr, par, host_ctxt); - else - __hyp_call_panic_vhe(spsr, elr, par, host_ctxt); - - unreachable(); -} |