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 
16 static 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  */
35 int __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