KVM: ppc: Handle guest idle by emulating MSR[WE] writes
[linux-2.6.git] / arch / powerpc / kvm / powerpc.c
1 /*
2  * This program is free software; you can redistribute it and/or modify
3  * it under the terms of the GNU General Public License, version 2, as
4  * published by the Free Software Foundation.
5  *
6  * This program is distributed in the hope that it will be useful,
7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
9  * GNU General Public License for more details.
10  *
11  * You should have received a copy of the GNU General Public License
12  * along with this program; if not, write to the Free Software
13  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
14  *
15  * Copyright IBM Corp. 2007
16  *
17  * Authors: Hollis Blanchard <hollisb@us.ibm.com>
18  *          Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
19  */
20
21 #include <linux/errno.h>
22 #include <linux/err.h>
23 #include <linux/kvm_host.h>
24 #include <linux/module.h>
25 #include <linux/vmalloc.h>
26 #include <linux/fs.h>
27 #include <asm/cputable.h>
28 #include <asm/uaccess.h>
29 #include <asm/kvm_ppc.h>
30
31
32 gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn)
33 {
34         return gfn;
35 }
36
37 int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
38 {
39         return !!(v->arch.pending_exceptions);
40 }
41
42 int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
43 {
44         return !(v->arch.msr & MSR_WE);
45 }
46
47
48 int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu)
49 {
50         enum emulation_result er;
51         int r;
52
53         er = kvmppc_emulate_instruction(run, vcpu);
54         switch (er) {
55         case EMULATE_DONE:
56                 /* Future optimization: only reload non-volatiles if they were
57                  * actually modified. */
58                 r = RESUME_GUEST_NV;
59                 break;
60         case EMULATE_DO_MMIO:
61                 run->exit_reason = KVM_EXIT_MMIO;
62                 /* We must reload nonvolatiles because "update" load/store
63                  * instructions modify register state. */
64                 /* Future optimization: only reload non-volatiles if they were
65                  * actually modified. */
66                 r = RESUME_HOST_NV;
67                 break;
68         case EMULATE_FAIL:
69                 /* XXX Deliver Program interrupt to guest. */
70                 printk(KERN_EMERG "%s: emulation failed (%08x)\n", __func__,
71                        vcpu->arch.last_inst);
72                 r = RESUME_HOST;
73                 break;
74         default:
75                 BUG();
76         }
77
78         return r;
79 }
80
81 void kvm_arch_hardware_enable(void *garbage)
82 {
83 }
84
85 void kvm_arch_hardware_disable(void *garbage)
86 {
87 }
88
89 int kvm_arch_hardware_setup(void)
90 {
91         return 0;
92 }
93
94 void kvm_arch_hardware_unsetup(void)
95 {
96 }
97
98 void kvm_arch_check_processor_compat(void *rtn)
99 {
100         int r;
101
102         if (strcmp(cur_cpu_spec->platform, "ppc440") == 0)
103                 r = 0;
104         else
105                 r = -ENOTSUPP;
106
107         *(int *)rtn = r;
108 }
109
110 struct kvm *kvm_arch_create_vm(void)
111 {
112         struct kvm *kvm;
113
114         kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL);
115         if (!kvm)
116                 return ERR_PTR(-ENOMEM);
117
118         return kvm;
119 }
120
121 static void kvmppc_free_vcpus(struct kvm *kvm)
122 {
123         unsigned int i;
124
125         for (i = 0; i < KVM_MAX_VCPUS; ++i) {
126                 if (kvm->vcpus[i]) {
127                         kvm_arch_vcpu_free(kvm->vcpus[i]);
128                         kvm->vcpus[i] = NULL;
129                 }
130         }
131 }
132
133 void kvm_arch_destroy_vm(struct kvm *kvm)
134 {
135         kvmppc_free_vcpus(kvm);
136         kvm_free_physmem(kvm);
137         kfree(kvm);
138 }
139
140 int kvm_dev_ioctl_check_extension(long ext)
141 {
142         int r;
143
144         switch (ext) {
145         case KVM_CAP_USER_MEMORY:
146                 r = 1;
147                 break;
148         default:
149                 r = 0;
150                 break;
151         }
152         return r;
153
154 }
155
156 long kvm_arch_dev_ioctl(struct file *filp,
157                         unsigned int ioctl, unsigned long arg)
158 {
159         return -EINVAL;
160 }
161
162 int kvm_arch_set_memory_region(struct kvm *kvm,
163                                struct kvm_userspace_memory_region *mem,
164                                struct kvm_memory_slot old,
165                                int user_alloc)
166 {
167         return 0;
168 }
169
170 struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
171 {
172         struct kvm_vcpu *vcpu;
173         int err;
174
175         vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
176         if (!vcpu) {
177                 err = -ENOMEM;
178                 goto out;
179         }
180
181         err = kvm_vcpu_init(vcpu, kvm, id);
182         if (err)
183                 goto free_vcpu;
184
185         return vcpu;
186
187 free_vcpu:
188         kmem_cache_free(kvm_vcpu_cache, vcpu);
189 out:
190         return ERR_PTR(err);
191 }
192
193 void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
194 {
195         kvm_vcpu_uninit(vcpu);
196         kmem_cache_free(kvm_vcpu_cache, vcpu);
197 }
198
199 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
200 {
201         kvm_arch_vcpu_free(vcpu);
202 }
203
204 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
205 {
206         unsigned int priority = exception_priority[BOOKE_INTERRUPT_DECREMENTER];
207
208         return test_bit(priority, &vcpu->arch.pending_exceptions);
209 }
210
211 static void kvmppc_decrementer_func(unsigned long data)
212 {
213         struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data;
214
215         kvmppc_queue_exception(vcpu, BOOKE_INTERRUPT_DECREMENTER);
216
217         if (waitqueue_active(&vcpu->wq)) {
218                 wake_up_interruptible(&vcpu->wq);
219                 vcpu->stat.halt_wakeup++;
220         }
221 }
222
223 int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
224 {
225         setup_timer(&vcpu->arch.dec_timer, kvmppc_decrementer_func,
226                     (unsigned long)vcpu);
227
228         return 0;
229 }
230
231 void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
232 {
233 }
234
235 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
236 {
237 }
238
239 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
240 {
241 }
242
243 void decache_vcpus_on_cpu(int cpu)
244 {
245 }
246
247 int kvm_arch_vcpu_ioctl_debug_guest(struct kvm_vcpu *vcpu,
248                                     struct kvm_debug_guest *dbg)
249 {
250         return -ENOTSUPP;
251 }
252
253 static void kvmppc_complete_dcr_load(struct kvm_vcpu *vcpu,
254                                      struct kvm_run *run)
255 {
256         u32 *gpr = &vcpu->arch.gpr[vcpu->arch.io_gpr];
257         *gpr = run->dcr.data;
258 }
259
260 static void kvmppc_complete_mmio_load(struct kvm_vcpu *vcpu,
261                                       struct kvm_run *run)
262 {
263         u32 *gpr = &vcpu->arch.gpr[vcpu->arch.io_gpr];
264
265         if (run->mmio.len > sizeof(*gpr)) {
266                 printk(KERN_ERR "bad MMIO length: %d\n", run->mmio.len);
267                 return;
268         }
269
270         if (vcpu->arch.mmio_is_bigendian) {
271                 switch (run->mmio.len) {
272                 case 4: *gpr = *(u32 *)run->mmio.data; break;
273                 case 2: *gpr = *(u16 *)run->mmio.data; break;
274                 case 1: *gpr = *(u8 *)run->mmio.data; break;
275                 }
276         } else {
277                 /* Convert BE data from userland back to LE. */
278                 switch (run->mmio.len) {
279                 case 4: *gpr = ld_le32((u32 *)run->mmio.data); break;
280                 case 2: *gpr = ld_le16((u16 *)run->mmio.data); break;
281                 case 1: *gpr = *(u8 *)run->mmio.data; break;
282                 }
283         }
284 }
285
286 int kvmppc_handle_load(struct kvm_run *run, struct kvm_vcpu *vcpu,
287                        unsigned int rt, unsigned int bytes, int is_bigendian)
288 {
289         if (bytes > sizeof(run->mmio.data)) {
290                 printk(KERN_ERR "%s: bad MMIO length: %d\n", __func__,
291                        run->mmio.len);
292         }
293
294         run->mmio.phys_addr = vcpu->arch.paddr_accessed;
295         run->mmio.len = bytes;
296         run->mmio.is_write = 0;
297
298         vcpu->arch.io_gpr = rt;
299         vcpu->arch.mmio_is_bigendian = is_bigendian;
300         vcpu->mmio_needed = 1;
301         vcpu->mmio_is_write = 0;
302
303         return EMULATE_DO_MMIO;
304 }
305
306 int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu,
307                         u32 val, unsigned int bytes, int is_bigendian)
308 {
309         void *data = run->mmio.data;
310
311         if (bytes > sizeof(run->mmio.data)) {
312                 printk(KERN_ERR "%s: bad MMIO length: %d\n", __func__,
313                        run->mmio.len);
314         }
315
316         run->mmio.phys_addr = vcpu->arch.paddr_accessed;
317         run->mmio.len = bytes;
318         run->mmio.is_write = 1;
319         vcpu->mmio_needed = 1;
320         vcpu->mmio_is_write = 1;
321
322         /* Store the value at the lowest bytes in 'data'. */
323         if (is_bigendian) {
324                 switch (bytes) {
325                 case 4: *(u32 *)data = val; break;
326                 case 2: *(u16 *)data = val; break;
327                 case 1: *(u8  *)data = val; break;
328                 }
329         } else {
330                 /* Store LE value into 'data'. */
331                 switch (bytes) {
332                 case 4: st_le32(data, val); break;
333                 case 2: st_le16(data, val); break;
334                 case 1: *(u8 *)data = val; break;
335                 }
336         }
337
338         return EMULATE_DO_MMIO;
339 }
340
341 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
342 {
343         int r;
344         sigset_t sigsaved;
345
346         vcpu_load(vcpu);
347
348         if (vcpu->sigset_active)
349                 sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
350
351         if (vcpu->mmio_needed) {
352                 if (!vcpu->mmio_is_write)
353                         kvmppc_complete_mmio_load(vcpu, run);
354                 vcpu->mmio_needed = 0;
355         } else if (vcpu->arch.dcr_needed) {
356                 if (!vcpu->arch.dcr_is_write)
357                         kvmppc_complete_dcr_load(vcpu, run);
358                 vcpu->arch.dcr_needed = 0;
359         }
360
361         kvmppc_check_and_deliver_interrupts(vcpu);
362
363         local_irq_disable();
364         kvm_guest_enter();
365         r = __kvmppc_vcpu_run(run, vcpu);
366         kvm_guest_exit();
367         local_irq_enable();
368
369         if (vcpu->sigset_active)
370                 sigprocmask(SIG_SETMASK, &sigsaved, NULL);
371
372         vcpu_put(vcpu);
373
374         return r;
375 }
376
377 int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
378 {
379         kvmppc_queue_exception(vcpu, BOOKE_INTERRUPT_EXTERNAL);
380
381         if (waitqueue_active(&vcpu->wq)) {
382                 wake_up_interruptible(&vcpu->wq);
383                 vcpu->stat.halt_wakeup++;
384         }
385
386         return 0;
387 }
388
389 int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
390                                     struct kvm_mp_state *mp_state)
391 {
392         return -EINVAL;
393 }
394
395 int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
396                                     struct kvm_mp_state *mp_state)
397 {
398         return -EINVAL;
399 }
400
401 long kvm_arch_vcpu_ioctl(struct file *filp,
402                          unsigned int ioctl, unsigned long arg)
403 {
404         struct kvm_vcpu *vcpu = filp->private_data;
405         void __user *argp = (void __user *)arg;
406         long r;
407
408         switch (ioctl) {
409         case KVM_INTERRUPT: {
410                 struct kvm_interrupt irq;
411                 r = -EFAULT;
412                 if (copy_from_user(&irq, argp, sizeof(irq)))
413                         goto out;
414                 r = kvm_vcpu_ioctl_interrupt(vcpu, &irq);
415                 break;
416         }
417         default:
418                 r = -EINVAL;
419         }
420
421 out:
422         return r;
423 }
424
425 int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
426 {
427         return -ENOTSUPP;
428 }
429
430 long kvm_arch_vm_ioctl(struct file *filp,
431                        unsigned int ioctl, unsigned long arg)
432 {
433         long r;
434
435         switch (ioctl) {
436         default:
437                 r = -EINVAL;
438         }
439
440         return r;
441 }
442
443 int kvm_arch_init(void *opaque)
444 {
445         return 0;
446 }
447
448 void kvm_arch_exit(void)
449 {
450 }