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