kvm/hyp/vgic-v2-cpuif-proxy.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (C) 2012-2015 - ARM Ltd
0004  * Author: Marc Zyngier <marc.zyngier@arm.com>
0005  */
0006
0007 #include <hyp/adjust_pc.h>
0008
0009 #include <linux/compiler.h>
0010 #include <linux/irqchip/arm-gic.h>
0011 #include <linux/kvm_host.h>
0012 #include <linux/swab.h>
0013
0014 #include <asm/kvm_emulate.h>
0015 #include <asm/kvm_hyp.h>
0016 #include <asm/kvm_mmu.h>
0017
0018 static bool __is_be(struct kvm_vcpu *vcpu)
0019 {
0020     if (vcpu_mode_is_32bit(vcpu))
0021         return !!(read_sysreg_el2(SYS_SPSR) & PSR_AA32_E_BIT);
0022
0023     return !!(read_sysreg(SCTLR_EL1) & SCTLR_ELx_EE);
0024 }
0025
0026 /*
0027  * __vgic_v2_perform_cpuif_access -- perform a GICV access on behalf of the
0028  *                   guest.
0029  *
0030  * @vcpu: the offending vcpu
0031  *
0032  * Returns:
0033  *  1: GICV access successfully performed
0034  *  0: Not a GICV access
0035  * -1: Illegal GICV access successfully performed
0036  */
0037 int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu)
0038 {
0039     struct kvm *kvm = kern_hyp_va(vcpu->kvm);
0040     struct vgic_dist *vgic = &kvm->arch.vgic;
0041     phys_addr_t fault_ipa;
0042     void __iomem *addr;
0043     int rd;
0044
0045     /* Build the full address */
0046     fault_ipa  = kvm_vcpu_get_fault_ipa(vcpu);
0047     fault_ipa |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0);
0048
0049     /* If not for GICV, move on */
0050     if (fault_ipa <  vgic->vgic_cpu_base ||
0051         fault_ipa >= (vgic->vgic_cpu_base + KVM_VGIC_V2_CPU_SIZE))
0052         return 0;
0053
0054     /* Reject anything but a 32bit access */
0055     if (kvm_vcpu_dabt_get_as(vcpu) != sizeof(u32)) {
0056         __kvm_skip_instr(vcpu);
0057         return -1;
0058     }
0059
0060     /* Not aligned? Don't bother */
0061     if (fault_ipa & 3) {
0062         __kvm_skip_instr(vcpu);
0063         return -1;
0064     }
0065
0066     rd = kvm_vcpu_dabt_get_rd(vcpu);
0067     addr  = kvm_vgic_global_state.vcpu_hyp_va;
0068     addr += fault_ipa - vgic->vgic_cpu_base;
0069
0070     if (kvm_vcpu_dabt_iswrite(vcpu)) {
0071         u32 data = vcpu_get_reg(vcpu, rd);
0072         if (__is_be(vcpu)) {
0073             /* guest pre-swabbed data, undo this for writel() */
0074             data = __kvm_swab32(data);
0075         }
0076         writel_relaxed(data, addr);
0077     } else {
0078         u32 data = readl_relaxed(addr);
0079         if (__is_be(vcpu)) {
0080             /* guest expects swabbed data */
0081             data = __kvm_swab32(data);
0082         }
0083         vcpu_set_reg(vcpu, rd, data);
0084     }
0085
0086     __kvm_skip_instr(vcpu);
0087
0088     return 1;
0089 }