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
18static 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_el1(SYS_SCTLR) & 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 */
37int __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	/* Handle deactivation as a normal exit */
67	if ((fault_ipa - vgic->vgic_cpu_base) >= GIC_CPU_DEACTIVATE)
68		return 0;
69
70	rd = kvm_vcpu_dabt_get_rd(vcpu);
71	addr  = kvm_vgic_global_state.vcpu_hyp_va;
72	addr += fault_ipa - vgic->vgic_cpu_base;
73
74	if (kvm_vcpu_dabt_iswrite(vcpu)) {
75		u32 data = vcpu_get_reg(vcpu, rd);
76		if (__is_be(vcpu)) {
77			/* guest pre-swabbed data, undo this for writel() */
78			data = __kvm_swab32(data);
79		}
80		writel_relaxed(data, addr);
81	} else {
82		u32 data = readl_relaxed(addr);
83		if (__is_be(vcpu)) {
84			/* guest expects swabbed data */
85			data = __kvm_swab32(data);
86		}
87		vcpu_set_reg(vcpu, rd, data);
88	}
89
90	__kvm_skip_instr(vcpu);
91
92	return 1;
93}