1 /* 2 * Copyright (C) 2012-2015 - ARM Ltd 3 * Author: Marc Zyngier <marc.zyngier@arm.com> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program. If not, see <http://www.gnu.org/licenses/>. 16 */ 17 18 #include <linux/compiler.h> 19 #include <linux/irqchip/arm-gic.h> 20 #include <linux/kvm_host.h> 21 #include <linux/swab.h> 22 23 #include <asm/kvm_emulate.h> 24 #include <asm/kvm_hyp.h> 25 #include <asm/kvm_mmu.h> 26 27 static bool __hyp_text __is_be(struct kvm_vcpu *vcpu) 28 { 29 if (vcpu_mode_is_32bit(vcpu)) 30 return !!(read_sysreg_el2(spsr) & PSR_AA32_E_BIT); 31 32 return !!(read_sysreg(SCTLR_EL1) & SCTLR_ELx_EE); 33 } 34 35 /* 36 * __vgic_v2_perform_cpuif_access -- perform a GICV access on behalf of the 37 * guest. 38 * 39 * @vcpu: the offending vcpu 40 * 41 * Returns: 42 * 1: GICV access successfully performed 43 * 0: Not a GICV access 44 * -1: Illegal GICV access successfully performed 45 */ 46 int __hyp_text __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu) 47 { 48 struct kvm *kvm = kern_hyp_va(vcpu->kvm); 49 struct vgic_dist *vgic = &kvm->arch.vgic; 50 phys_addr_t fault_ipa; 51 void __iomem *addr; 52 int rd; 53 54 /* Build the full address */ 55 fault_ipa = kvm_vcpu_get_fault_ipa(vcpu); 56 fault_ipa |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0); 57 58 /* If not for GICV, move on */ 59 if (fault_ipa < vgic->vgic_cpu_base || 60 fault_ipa >= (vgic->vgic_cpu_base + KVM_VGIC_V2_CPU_SIZE)) 61 return 0; 62 63 /* Reject anything but a 32bit access */ 64 if (kvm_vcpu_dabt_get_as(vcpu) != sizeof(u32)) { 65 __kvm_skip_instr(vcpu); 66 return -1; 67 } 68 69 /* Not aligned? Don't bother */ 70 if (fault_ipa & 3) { 71 __kvm_skip_instr(vcpu); 72 return -1; 73 } 74 75 rd = kvm_vcpu_dabt_get_rd(vcpu); 76 addr = hyp_symbol_addr(kvm_vgic_global_state)->vcpu_hyp_va; 77 addr += fault_ipa - vgic->vgic_cpu_base; 78 79 if (kvm_vcpu_dabt_iswrite(vcpu)) { 80 u32 data = vcpu_get_reg(vcpu, rd); 81 if (__is_be(vcpu)) { 82 /* guest pre-swabbed data, undo this for writel() */ 83 data = swab32(data); 84 } 85 writel_relaxed(data, addr); 86 } else { 87 u32 data = readl_relaxed(addr); 88 if (__is_be(vcpu)) { 89 /* guest expects swabbed data */ 90 data = swab32(data); 91 } 92 vcpu_set_reg(vcpu, rd, data); 93 } 94 95 __kvm_skip_instr(vcpu); 96 97 return 1; 98 } 99