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
16static 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 */
35int __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}
88