247 lines
		
	
	
		
			6.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			247 lines
		
	
	
		
			6.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0-only
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/*
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 * Copyright (C) 2015 - ARM Ltd
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 * Author: Marc Zyngier <marc.zyngier@arm.com>
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 */
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#include <hyp/switch.h>
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#include <linux/arm-smccc.h>
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#include <linux/kvm_host.h>
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#include <linux/types.h>
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#include <linux/jump_label.h>
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#include <linux/percpu.h>
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#include <uapi/linux/psci.h>
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#include <kvm/arm_psci.h>
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#include <asm/barrier.h>
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#include <asm/cpufeature.h>
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#include <asm/kprobes.h>
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#include <asm/kvm_asm.h>
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#include <asm/kvm_emulate.h>
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#include <asm/kvm_hyp.h>
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#include <asm/kvm_mmu.h>
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#include <asm/fpsimd.h>
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#include <asm/debug-monitors.h>
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#include <asm/processor.h>
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#include <asm/thread_info.h>
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#include <asm/vectors.h>
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/* VHE specific context */
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DEFINE_PER_CPU(struct kvm_host_data, kvm_host_data);
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DEFINE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt);
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DEFINE_PER_CPU(unsigned long, kvm_hyp_vector);
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static void __activate_traps(struct kvm_vcpu *vcpu)
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{
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	u64 val;
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	___activate_traps(vcpu);
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	val = read_sysreg(cpacr_el1);
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	val |= CPACR_EL1_TTA;
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	val &= ~(CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN |
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		 CPACR_EL1_SMEN_EL0EN | CPACR_EL1_SMEN_EL1EN);
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	/*
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	 * With VHE (HCR.E2H == 1), accesses to CPACR_EL1 are routed to
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	 * CPTR_EL2. In general, CPACR_EL1 has the same layout as CPTR_EL2,
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	 * except for some missing controls, such as TAM.
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	 * In this case, CPTR_EL2.TAM has the same position with or without
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	 * VHE (HCR.E2H == 1) which allows us to use here the CPTR_EL2.TAM
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	 * shift value for trapping the AMU accesses.
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	 */
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	val |= CPTR_EL2_TAM;
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	if (guest_owns_fp_regs(vcpu)) {
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		if (vcpu_has_sve(vcpu))
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			val |= CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN;
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	} else {
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		val &= ~(CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN);
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		__activate_traps_fpsimd32(vcpu);
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	}
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	write_sysreg(val, cpacr_el1);
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	write_sysreg(__this_cpu_read(kvm_hyp_vector), vbar_el1);
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}
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NOKPROBE_SYMBOL(__activate_traps);
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static void __deactivate_traps(struct kvm_vcpu *vcpu)
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{
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	const char *host_vectors = vectors;
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	___deactivate_traps(vcpu);
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	write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);
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	/*
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	 * ARM errata 1165522 and 1530923 require the actual execution of the
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	 * above before we can switch to the EL2/EL0 translation regime used by
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	 * the host.
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	 */
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	asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_SPECULATIVE_AT));
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	write_sysreg(CPACR_EL1_DEFAULT, cpacr_el1);
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	if (!arm64_kernel_unmapped_at_el0())
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		host_vectors = __this_cpu_read(this_cpu_vector);
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	write_sysreg(host_vectors, vbar_el1);
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}
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NOKPROBE_SYMBOL(__deactivate_traps);
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void activate_traps_vhe_load(struct kvm_vcpu *vcpu)
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{
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	__activate_traps_common(vcpu);
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}
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void deactivate_traps_vhe_put(struct kvm_vcpu *vcpu)
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{
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	__deactivate_traps_common(vcpu);
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}
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static const exit_handler_fn hyp_exit_handlers[] = {
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	[0 ... ESR_ELx_EC_MAX]		= NULL,
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	[ESR_ELx_EC_CP15_32]		= kvm_hyp_handle_cp15_32,
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	[ESR_ELx_EC_SYS64]		= kvm_hyp_handle_sysreg,
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	[ESR_ELx_EC_SVE]		= kvm_hyp_handle_fpsimd,
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	[ESR_ELx_EC_FP_ASIMD]		= kvm_hyp_handle_fpsimd,
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	[ESR_ELx_EC_IABT_LOW]		= kvm_hyp_handle_iabt_low,
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	[ESR_ELx_EC_DABT_LOW]		= kvm_hyp_handle_dabt_low,
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	[ESR_ELx_EC_WATCHPT_LOW]	= kvm_hyp_handle_watchpt_low,
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	[ESR_ELx_EC_PAC]		= kvm_hyp_handle_ptrauth,
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};
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static const exit_handler_fn *kvm_get_exit_handler_array(struct kvm_vcpu *vcpu)
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{
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	return hyp_exit_handlers;
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}
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static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code)
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{
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}
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/* Switch to the guest for VHE systems running in EL2 */
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static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
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{
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	struct kvm_cpu_context *host_ctxt;
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	struct kvm_cpu_context *guest_ctxt;
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	u64 exit_code;
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	host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
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	host_ctxt->__hyp_running_vcpu = vcpu;
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	guest_ctxt = &vcpu->arch.ctxt;
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	sysreg_save_host_state_vhe(host_ctxt);
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	/*
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	 * ARM erratum 1165522 requires us to configure both stage 1 and
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	 * stage 2 translation for the guest context before we clear
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	 * HCR_EL2.TGE.
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	 *
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	 * We have already configured the guest's stage 1 translation in
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	 * kvm_vcpu_load_sysregs_vhe above.  We must now call
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	 * __load_stage2 before __activate_traps, because
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	 * __load_stage2 configures stage 2 translation, and
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	 * __activate_traps clear HCR_EL2.TGE (among other things).
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	 */
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	__load_stage2(vcpu->arch.hw_mmu, vcpu->arch.hw_mmu->arch);
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	__activate_traps(vcpu);
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	__kvm_adjust_pc(vcpu);
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	sysreg_restore_guest_state_vhe(guest_ctxt);
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	__debug_switch_to_guest(vcpu);
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	do {
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		/* Jump in the fire! */
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		exit_code = __guest_enter(vcpu);
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		/* And we're baaack! */
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	} while (fixup_guest_exit(vcpu, &exit_code));
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	sysreg_save_guest_state_vhe(guest_ctxt);
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	__deactivate_traps(vcpu);
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	sysreg_restore_host_state_vhe(host_ctxt);
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	if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED)
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		__fpsimd_save_fpexc32(vcpu);
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	__debug_switch_to_host(vcpu);
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	return exit_code;
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}
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NOKPROBE_SYMBOL(__kvm_vcpu_run_vhe);
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int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
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{
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	int ret;
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	local_daif_mask();
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	/*
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	 * Having IRQs masked via PMR when entering the guest means the GIC
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	 * will not signal the CPU of interrupts of lower priority, and the
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	 * only way to get out will be via guest exceptions.
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	 * Naturally, we want to avoid this.
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	 *
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	 * local_daif_mask() already sets GIC_PRIO_PSR_I_SET, we just need a
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	 * dsb to ensure the redistributor is forwards EL2 IRQs to the CPU.
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	 */
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	pmr_sync();
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	ret = __kvm_vcpu_run_vhe(vcpu);
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	/*
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	 * local_daif_restore() takes care to properly restore PSTATE.DAIF
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	 * and the GIC PMR if the host is using IRQ priorities.
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	 */
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	local_daif_restore(DAIF_PROCCTX_NOIRQ);
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	/*
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	 * When we exit from the guest we change a number of CPU configuration
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	 * parameters, such as traps.  Make sure these changes take effect
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	 * before running the host or additional guests.
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	 */
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	isb();
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	return ret;
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}
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static void __hyp_call_panic(u64 spsr, u64 elr, u64 par)
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{
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	struct kvm_cpu_context *host_ctxt;
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	struct kvm_vcpu *vcpu;
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	host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
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	vcpu = host_ctxt->__hyp_running_vcpu;
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	__deactivate_traps(vcpu);
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	sysreg_restore_host_state_vhe(host_ctxt);
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	panic("HYP panic:\nPS:%08llx PC:%016llx ESR:%08llx\nFAR:%016llx HPFAR:%016llx PAR:%016llx\nVCPU:%p\n",
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	      spsr, elr,
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	      read_sysreg_el2(SYS_ESR), read_sysreg_el2(SYS_FAR),
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	      read_sysreg(hpfar_el2), par, vcpu);
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}
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NOKPROBE_SYMBOL(__hyp_call_panic);
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void __noreturn hyp_panic(void)
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{
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	u64 spsr = read_sysreg_el2(SYS_SPSR);
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	u64 elr = read_sysreg_el2(SYS_ELR);
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	u64 par = read_sysreg_par();
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	__hyp_call_panic(spsr, elr, par);
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	unreachable();
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}
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asmlinkage void kvm_unexpected_el2_exception(void)
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{
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	__kvm_unexpected_el2_exception();
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}
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