2 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
3 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
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.
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.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
19 #include <linux/kvm_host.h>
20 #include <asm/kvm_mmio.h>
21 #include <asm/kvm_emulate.h>
22 #include <trace/events/kvm.h>
27 * kvm_handle_mmio_return -- Handle MMIO loads after user space emulation
28 * @vcpu: The VCPU pointer
29 * @run: The VCPU run struct containing the mmio data
31 * This should only be called after returning from userspace for MMIO load
34 int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
40 if (!run->mmio.is_write) {
41 dest = vcpu_reg(vcpu, vcpu->arch.mmio_decode.rt);
42 memset(dest, 0, sizeof(int));
48 memcpy(dest, run->mmio.data, len);
50 trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr,
51 *((u64 *)run->mmio.data));
53 if (vcpu->arch.mmio_decode.sign_extend && len < 4) {
54 mask = 1U << ((len * 8) - 1);
55 *dest = (*dest ^ mask) - mask;
62 static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
63 struct kvm_exit_mmio *mmio)
65 unsigned long rt, len;
66 bool is_write, sign_extend;
68 if (kvm_vcpu_dabt_isextabt(vcpu)) {
69 /* cache operation on I/O addr, tell guest unsupported */
70 kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
74 if (kvm_vcpu_dabt_iss1tw(vcpu)) {
75 /* page table accesses IO mem: tell guest to fix its TTBR */
76 kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
80 len = kvm_vcpu_dabt_get_as(vcpu);
81 if (unlikely(len < 0))
84 is_write = kvm_vcpu_dabt_iswrite(vcpu);
85 sign_extend = kvm_vcpu_dabt_issext(vcpu);
86 rt = kvm_vcpu_dabt_get_rd(vcpu);
88 if (kvm_vcpu_reg_is_pc(vcpu, rt)) {
89 /* IO memory trying to read/write pc */
90 kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu));
94 mmio->is_write = is_write;
95 mmio->phys_addr = fault_ipa;
97 vcpu->arch.mmio_decode.sign_extend = sign_extend;
98 vcpu->arch.mmio_decode.rt = rt;
101 * The MMIO instruction is emulated and should not be re-executed
104 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
108 int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
109 phys_addr_t fault_ipa)
111 struct kvm_exit_mmio mmio;
116 * Prepare MMIO operation. First stash it in a private
117 * structure that we can use for in-kernel emulation. If the
118 * kernel can't handle it, copy it into run->mmio and let user
119 * space do its magic.
122 if (kvm_vcpu_dabt_isvalid(vcpu)) {
123 ret = decode_hsr(vcpu, fault_ipa, &mmio);
127 kvm_err("load/store instruction decoding not implemented\n");
131 rt = vcpu->arch.mmio_decode.rt;
132 trace_kvm_mmio((mmio.is_write) ? KVM_TRACE_MMIO_WRITE :
133 KVM_TRACE_MMIO_READ_UNSATISFIED,
135 (mmio.is_write) ? *vcpu_reg(vcpu, rt) : 0);
138 memcpy(mmio.data, vcpu_reg(vcpu, rt), mmio.len);
140 if (vgic_handle_mmio(vcpu, run, &mmio))
143 kvm_prepare_mmio(run, &mmio);