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 }
90
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