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

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2012-2015 - ARM Ltd
   4 * Author: Marc Zyngier <marc.zyngier@arm.com>
   5 */
   6
   7#include <hyp/adjust_pc.h>
   8
   9#include <linux/compiler.h>
  10#include <linux/irqchip/arm-gic.h>
  11#include <linux/kvm_host.h>
  12#include <linux/swab.h>
  13
  14#include <asm/kvm_emulate.h>
  15#include <asm/kvm_hyp.h>
  16#include <asm/kvm_mmu.h>
  17
  18static bool __is_be(struct kvm_vcpu *vcpu)
  19{
  20        if (vcpu_mode_is_32bit(vcpu))
  21                return !!(read_sysreg_el2(SYS_SPSR) & PSR_AA32_E_BIT);
  22
  23        return !!(read_sysreg(SCTLR_EL1) & SCTLR_ELx_EE);
  24}
  25
  26/*
  27 * __vgic_v2_perform_cpuif_access -- perform a GICV access on behalf of the
  28 *                                   guest.
  29 *
  30 * @vcpu: the offending vcpu
  31 *
  32 * Returns:
  33 *  1: GICV access successfully performed
  34 *  0: Not a GICV access
  35 * -1: Illegal GICV access successfully performed
  36 */
  37int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu)
  38{
  39        struct kvm *kvm = kern_hyp_va(vcpu->kvm);
  40        struct vgic_dist *vgic = &kvm->arch.vgic;
  41        phys_addr_t fault_ipa;
  42        void __iomem *addr;
  43        int rd;
  44
  45        /* Build the full address */
  46        fault_ipa  = kvm_vcpu_get_fault_ipa(vcpu);
  47        fault_ipa |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0);
  48
  49        /* If not for GICV, move on */
  50        if (fault_ipa <  vgic->vgic_cpu_base ||
  51            fault_ipa >= (vgic->vgic_cpu_base + KVM_VGIC_V2_CPU_SIZE))
  52                return 0;
  53
  54        /* Reject anything but a 32bit access */
  55        if (kvm_vcpu_dabt_get_as(vcpu) != sizeof(u32)) {
  56                __kvm_skip_instr(vcpu);
  57                return -1;
  58        }
  59
  60        /* Not aligned? Don't bother */
  61        if (fault_ipa & 3) {
  62                __kvm_skip_instr(vcpu);
  63                return -1;
  64        }
  65
  66        rd = kvm_vcpu_dabt_get_rd(vcpu);
  67        addr  = hyp_symbol_addr(kvm_vgic_global_state)->vcpu_hyp_va;
  68        addr += fault_ipa - vgic->vgic_cpu_base;
  69
  70        if (kvm_vcpu_dabt_iswrite(vcpu)) {
  71                u32 data = vcpu_get_reg(vcpu, rd);
  72                if (__is_be(vcpu)) {
  73                        /* guest pre-swabbed data, undo this for writel() */
  74                        data = __kvm_swab32(data);
  75                }
  76                writel_relaxed(data, addr);
  77        } else {
  78                u32 data = readl_relaxed(addr);
  79                if (__is_be(vcpu)) {
  80                        /* guest expects swabbed data */
  81                        data = __kvm_swab32(data);
  82                }
  83                vcpu_set_reg(vcpu, rd, data);
  84        }
  85
  86        __kvm_skip_instr(vcpu);
  87
  88        return 1;
  89}
  90