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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c
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// SPDX-License-Identifier: GPL-2.0-only

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/*

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 * Copyright (C) 2012-2015 - ARM Ltd

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 * Author: Marc Zyngier <[email protected]>

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 */

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#include <hyp/adjust_pc.h>

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#include <linux/compiler.h>

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#include <linux/irqchip/arm-gic.h>

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#include <linux/kvm_host.h>

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#include <linux/swab.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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static bool __is_be(struct kvm_vcpu *vcpu)

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{

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	if (vcpu_mode_is_32bit(vcpu))

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		return !!(read_sysreg_el2(SYS_SPSR) & PSR_AA32_E_BIT);

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	return !!(read_sysreg_el1(SYS_SCTLR) & SCTLR_ELx_EE);

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}

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/*

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 * __vgic_v2_perform_cpuif_access -- perform a GICV access on behalf of the

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 *				     guest.

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 *

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 * @vcpu: the offending vcpu

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 *

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 * Returns:

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 *  1: GICV access successfully performed

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 *  0: Not a GICV access

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 * -1: Illegal GICV access successfully performed

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 */

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int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu)

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{

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	struct kvm *kvm = kern_hyp_va(vcpu->kvm);

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	struct vgic_dist *vgic = &kvm->arch.vgic;

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	phys_addr_t fault_ipa;

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	void __iomem *addr;

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	int rd;

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	/* Build the full address */

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	fault_ipa  = kvm_vcpu_get_fault_ipa(vcpu);

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	fault_ipa |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0);

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	/* If not for GICV, move on */

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	if (fault_ipa <  vgic->vgic_cpu_base ||

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	    fault_ipa >= (vgic->vgic_cpu_base + KVM_VGIC_V2_CPU_SIZE))

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		return 0;

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	/* Reject anything but a 32bit access */

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	if (kvm_vcpu_dabt_get_as(vcpu) != sizeof(u32)) {

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		__kvm_skip_instr(vcpu);

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		return -1;

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	}

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	/* Not aligned? Don't bother */

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	if (fault_ipa & 3) {

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		__kvm_skip_instr(vcpu);

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		return -1;

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	}

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	rd = kvm_vcpu_dabt_get_rd(vcpu);

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	addr  = kvm_vgic_global_state.vcpu_hyp_va;

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	addr += fault_ipa - vgic->vgic_cpu_base;

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	if (kvm_vcpu_dabt_iswrite(vcpu)) {

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		u32 data = vcpu_get_reg(vcpu, rd);

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		if (__is_be(vcpu)) {

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			/* guest pre-swabbed data, undo this for writel() */

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			data = __kvm_swab32(data);

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		}

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		writel_relaxed(data, addr);

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	} else {

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		u32 data = readl_relaxed(addr);

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		if (__is_be(vcpu)) {

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			/* guest expects swabbed data */

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			data = __kvm_swab32(data);

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		}

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		vcpu_set_reg(vcpu, rd, data);

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	}

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	__kvm_skip_instr(vcpu);

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	return 1;

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}

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