xref: /openbmc/linux/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c (revision ca90578000afb0d8f177ea36f7259a9c3640cf49)
1 /*
2  * Copyright (C) 2012-2015 - ARM Ltd
3  * Author: Marc Zyngier <marc.zyngier@arm.com>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #include <linux/compiler.h>
19 #include <linux/irqchip/arm-gic.h>
20 #include <linux/kvm_host.h>
21 
22 #include <asm/kvm_emulate.h>
23 #include <asm/kvm_hyp.h>
24 #include <asm/kvm_mmu.h>
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
36  */
37 int __hyp_text __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 		return -1;
57 
58 	/* Not aligned? Don't bother */
59 	if (fault_ipa & 3)
60 		return -1;
61 
62 	rd = kvm_vcpu_dabt_get_rd(vcpu);
63 	addr  = hyp_symbol_addr(kvm_vgic_global_state)->vcpu_hyp_va;
64 	addr += fault_ipa - vgic->vgic_cpu_base;
65 
66 	if (kvm_vcpu_dabt_iswrite(vcpu)) {
67 		u32 data = vcpu_data_guest_to_host(vcpu,
68 						   vcpu_get_reg(vcpu, rd),
69 						   sizeof(u32));
70 		writel_relaxed(data, addr);
71 	} else {
72 		u32 data = readl_relaxed(addr);
73 		vcpu_set_reg(vcpu, rd, vcpu_data_host_to_guest(vcpu, data,
74 							       sizeof(u32)));
75 	}
76 
77 	return 1;
78 }
79