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>
26 static void mmio_write_buf(char *buf
, unsigned int len
, unsigned long data
)
55 memcpy(buf
, datap
, len
);
58 static unsigned long mmio_read_buf(char *buf
, unsigned int len
)
60 unsigned long data
= 0;
72 memcpy(&tmp
.hword
, buf
, len
);
76 memcpy(&tmp
.word
, buf
, len
);
80 memcpy(&tmp
.dword
, buf
, len
);
89 * kvm_handle_mmio_return -- Handle MMIO loads after user space emulation
90 * or in-kernel IO emulation
92 * @vcpu: The VCPU pointer
93 * @run: The VCPU run struct containing the mmio data
95 int kvm_handle_mmio_return(struct kvm_vcpu
*vcpu
, struct kvm_run
*run
)
101 if (!run
->mmio
.is_write
) {
103 if (len
> sizeof(unsigned long))
106 data
= mmio_read_buf(run
->mmio
.data
, len
);
108 if (vcpu
->arch
.mmio_decode
.sign_extend
&&
109 len
< sizeof(unsigned long)) {
110 mask
= 1U << ((len
* 8) - 1);
111 data
= (data
^ mask
) - mask
;
114 trace_kvm_mmio(KVM_TRACE_MMIO_READ
, len
, run
->mmio
.phys_addr
,
116 data
= vcpu_data_host_to_guest(vcpu
, data
, len
);
117 vcpu_set_reg(vcpu
, vcpu
->arch
.mmio_decode
.rt
, data
);
123 static int decode_hsr(struct kvm_vcpu
*vcpu
, bool *is_write
, int *len
)
129 if (kvm_vcpu_dabt_isextabt(vcpu
)) {
130 /* cache operation on I/O addr, tell guest unsupported */
131 kvm_inject_dabt(vcpu
, kvm_vcpu_get_hfar(vcpu
));
135 if (kvm_vcpu_dabt_iss1tw(vcpu
)) {
136 /* page table accesses IO mem: tell guest to fix its TTBR */
137 kvm_inject_dabt(vcpu
, kvm_vcpu_get_hfar(vcpu
));
141 access_size
= kvm_vcpu_dabt_get_as(vcpu
);
142 if (unlikely(access_size
< 0))
145 *is_write
= kvm_vcpu_dabt_iswrite(vcpu
);
146 sign_extend
= kvm_vcpu_dabt_issext(vcpu
);
147 rt
= kvm_vcpu_dabt_get_rd(vcpu
);
150 vcpu
->arch
.mmio_decode
.sign_extend
= sign_extend
;
151 vcpu
->arch
.mmio_decode
.rt
= rt
;
154 * The MMIO instruction is emulated and should not be re-executed
157 kvm_skip_instr(vcpu
, kvm_vcpu_trap_il_is32bit(vcpu
));
161 int io_mem_abort(struct kvm_vcpu
*vcpu
, struct kvm_run
*run
,
162 phys_addr_t fault_ipa
)
172 * Prepare MMIO operation. First decode the syndrome data we get
173 * from the CPU. Then try if some in-kernel emulation feels
174 * responsible, otherwise let user space do its magic.
176 if (kvm_vcpu_dabt_isvalid(vcpu
)) {
177 ret
= decode_hsr(vcpu
, &is_write
, &len
);
181 kvm_err("load/store instruction decoding not implemented\n");
185 rt
= vcpu
->arch
.mmio_decode
.rt
;
188 data
= vcpu_data_guest_to_host(vcpu
, vcpu_get_reg(vcpu
, rt
),
191 trace_kvm_mmio(KVM_TRACE_MMIO_WRITE
, len
, fault_ipa
, data
);
192 mmio_write_buf(data_buf
, len
, data
);
194 ret
= kvm_io_bus_write(vcpu
, KVM_MMIO_BUS
, fault_ipa
, len
,
197 trace_kvm_mmio(KVM_TRACE_MMIO_READ_UNSATISFIED
, len
,
200 ret
= kvm_io_bus_read(vcpu
, KVM_MMIO_BUS
, fault_ipa
, len
,
204 /* Now prepare kvm_run for the potential return to userland. */
205 run
->mmio
.is_write
= is_write
;
206 run
->mmio
.phys_addr
= fault_ipa
;
210 /* We handled the access successfully in the kernel. */
212 memcpy(run
->mmio
.data
, data_buf
, len
);
213 vcpu
->stat
.mmio_exit_kernel
++;
214 kvm_handle_mmio_return(vcpu
, run
);
219 memcpy(run
->mmio
.data
, data_buf
, len
);
220 vcpu
->stat
.mmio_exit_user
++;
221 run
->exit_reason
= KVM_EXIT_MMIO
;