linux-zen-server/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c

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2023-08-30 17:53:23 +02:00
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012-2015 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*/
#include <hyp/adjust_pc.h>
#include <linux/compiler.h>
#include <linux/irqchip/arm-gic.h>
#include <linux/kvm_host.h>
#include <linux/swab.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>
static bool __is_be(struct kvm_vcpu *vcpu)
{
if (vcpu_mode_is_32bit(vcpu))
return !!(read_sysreg_el2(SYS_SPSR) & PSR_AA32_E_BIT);
return !!(read_sysreg(SCTLR_EL1) & SCTLR_ELx_EE);
}
/*
* __vgic_v2_perform_cpuif_access -- perform a GICV access on behalf of the
* guest.
*
* @vcpu: the offending vcpu
*
* Returns:
* 1: GICV access successfully performed
* 0: Not a GICV access
* -1: Illegal GICV access successfully performed
*/
int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = kern_hyp_va(vcpu->kvm);
struct vgic_dist *vgic = &kvm->arch.vgic;
phys_addr_t fault_ipa;
void __iomem *addr;
int rd;
/* Build the full address */
fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
fault_ipa |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0);
/* If not for GICV, move on */
if (fault_ipa < vgic->vgic_cpu_base ||
fault_ipa >= (vgic->vgic_cpu_base + KVM_VGIC_V2_CPU_SIZE))
return 0;
/* Reject anything but a 32bit access */
if (kvm_vcpu_dabt_get_as(vcpu) != sizeof(u32)) {
__kvm_skip_instr(vcpu);
return -1;
}
/* Not aligned? Don't bother */
if (fault_ipa & 3) {
__kvm_skip_instr(vcpu);
return -1;
}
rd = kvm_vcpu_dabt_get_rd(vcpu);
addr = kvm_vgic_global_state.vcpu_hyp_va;
addr += fault_ipa - vgic->vgic_cpu_base;
if (kvm_vcpu_dabt_iswrite(vcpu)) {
u32 data = vcpu_get_reg(vcpu, rd);
if (__is_be(vcpu)) {
/* guest pre-swabbed data, undo this for writel() */
data = __kvm_swab32(data);
}
writel_relaxed(data, addr);
} else {
u32 data = readl_relaxed(addr);
if (__is_be(vcpu)) {
/* guest expects swabbed data */
data = __kvm_swab32(data);
}
vcpu_set_reg(vcpu, rd, data);
}
__kvm_skip_instr(vcpu);
return 1;
}