diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/vhe/switch.c')
| -rw-r--r-- | arch/arm64/kvm/hyp/vhe/switch.c | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c new file mode 100644 index 000000000000..c1da4f86ccac --- /dev/null +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -0,0 +1,224 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#include <hyp/switch.h> + +#include <linux/arm-smccc.h> +#include <linux/kvm_host.h> +#include <linux/types.h> +#include <linux/jump_label.h> +#include <uapi/linux/psci.h> + +#include <kvm/arm_psci.h> + +#include <asm/barrier.h> +#include <asm/cpufeature.h> +#include <asm/kprobes.h> +#include <asm/kvm_asm.h> +#include <asm/kvm_emulate.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> + +const char __hyp_panic_string[] = "HYP panic:\nPS:%08llx PC:%016llx ESR:%08llx\nFAR:%016llx HPFAR:%016llx PAR:%016llx\nVCPU:%p\n"; + +static void __activate_traps(struct kvm_vcpu *vcpu) +{ + u64 val; + + ___activate_traps(vcpu); + + val = read_sysreg(cpacr_el1); + val |= CPACR_EL1_TTA; + val &= ~CPACR_EL1_ZEN; + + /* + * With VHE (HCR.E2H == 1), accesses to CPACR_EL1 are routed to + * CPTR_EL2. In general, CPACR_EL1 has the same layout as CPTR_EL2, + * except for some missing controls, such as TAM. + * In this case, CPTR_EL2.TAM has the same position with or without + * VHE (HCR.E2H == 1) which allows us to use here the CPTR_EL2.TAM + * shift value for trapping the AMU accesses. + */ + + val |= CPTR_EL2_TAM; + + if (update_fp_enabled(vcpu)) { + if (vcpu_has_sve(vcpu)) + val |= CPACR_EL1_ZEN; + } else { + val &= ~CPACR_EL1_FPEN; + __activate_traps_fpsimd32(vcpu); + } + + write_sysreg(val, cpacr_el1); + + write_sysreg(kvm_get_hyp_vector(), vbar_el1); +} +NOKPROBE_SYMBOL(__activate_traps); + +static void __deactivate_traps(struct kvm_vcpu *vcpu) +{ + extern char vectors[]; /* kernel exception vectors */ + + ___deactivate_traps(vcpu); + + write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2); + + /* + * ARM errata 1165522 and 1530923 require 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_SPECULATIVE_AT)); + + write_sysreg(CPACR_EL1_DEFAULT, cpacr_el1); + write_sysreg(vectors, vbar_el1); +} +NOKPROBE_SYMBOL(__deactivate_traps); + +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(); +} + +/* Switch to the guest for VHE systems running in EL2 */ +static 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 = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt; + 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_vhe 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->arch.hw_mmu); + __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; +} +NOKPROBE_SYMBOL(__kvm_vcpu_run_vhe); + +int __kvm_vcpu_run(struct kvm_vcpu *vcpu) +{ + int ret; + + local_daif_mask(); + + /* + * Having IRQs masked via PMR when entering the guest means the GIC + * will not signal the CPU of interrupts of lower priority, and the + * only way to get out will be via guest exceptions. + * Naturally, we want to avoid this. + * + * local_daif_mask() already sets GIC_PRIO_PSR_I_SET, we just need a + * dsb to ensure the redistributor is forwards EL2 IRQs to the CPU. + */ + pmr_sync(); + + ret = __kvm_vcpu_run_vhe(vcpu); + + /* + * local_daif_restore() takes care to properly restore PSTATE.DAIF + * and the GIC PMR if the host is using IRQ priorities. + */ + local_daif_restore(DAIF_PROCCTX_NOIRQ); + + /* + * When we exit from the guest we change a number of CPU configuration + * parameters, such as traps. Make sure these changes take effect + * before running the host or additional guests. + */ + isb(); + + return ret; +} + +static void __hyp_call_panic(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(SYS_ESR), read_sysreg_el2(SYS_FAR), + read_sysreg(hpfar_el2), par, vcpu); +} +NOKPROBE_SYMBOL(__hyp_call_panic); + +void __noreturn hyp_panic(struct kvm_cpu_context *host_ctxt) +{ + u64 spsr = read_sysreg_el2(SYS_SPSR); + u64 elr = read_sysreg_el2(SYS_ELR); + u64 par = read_sysreg(par_el1); + + __hyp_call_panic(spsr, elr, par, host_ctxt); + unreachable(); +} + +asmlinkage void kvm_unexpected_el2_exception(void) +{ + return __kvm_unexpected_el2_exception(); +} |