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
  18 static 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  */
  37 int __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  = 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 }