xref: /linux/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c (revision d0034a7a4ac7fae708146ac0059b9c47a1543f0d)
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 
__is_be(struct kvm_vcpu * vcpu)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  */
__vgic_v2_perform_cpuif_access(struct kvm_vcpu * vcpu)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