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35#include <linux/init.h>
36#include <linux/types.h>
37#include <linux/kernel.h>
38#include <linux/slab.h>
39#include <linux/fs.h>
40#include <linux/device.h>
41#include <linux/miscdevice.h>
42#include <linux/uaccess.h>
43#include <linux/capability.h>
44#include <linux/poll.h>
45#include <linux/sched.h>
46
47#include <xen/interface/xen.h>
48#include <xen/events.h>
49#include <xen/interface/vcpu.h>
50#include <xen/xen.h>
51#include <asm/xen/hypercall.h>
52#include <asm/xen/hypervisor.h>
53
54#define XEN_MCELOG "xen_mcelog: "
55
56static struct mc_info g_mi;
57static struct mcinfo_logical_cpu *g_physinfo;
58static uint32_t ncpus;
59
60static DEFINE_MUTEX(mcelog_lock);
61
62static struct xen_mce_log xen_mcelog = {
63 .signature = XEN_MCE_LOG_SIGNATURE,
64 .len = XEN_MCE_LOG_LEN,
65 .recordlen = sizeof(struct xen_mce),
66};
67
68static DEFINE_SPINLOCK(xen_mce_chrdev_state_lock);
69static int xen_mce_chrdev_open_count;
70static int xen_mce_chrdev_open_exclu;
71
72static DECLARE_WAIT_QUEUE_HEAD(xen_mce_chrdev_wait);
73
74static int xen_mce_chrdev_open(struct inode *inode, struct file *file)
75{
76 spin_lock(&xen_mce_chrdev_state_lock);
77
78 if (xen_mce_chrdev_open_exclu ||
79 (xen_mce_chrdev_open_count && (file->f_flags & O_EXCL))) {
80 spin_unlock(&xen_mce_chrdev_state_lock);
81
82 return -EBUSY;
83 }
84
85 if (file->f_flags & O_EXCL)
86 xen_mce_chrdev_open_exclu = 1;
87 xen_mce_chrdev_open_count++;
88
89 spin_unlock(&xen_mce_chrdev_state_lock);
90
91 return nonseekable_open(inode, file);
92}
93
94static int xen_mce_chrdev_release(struct inode *inode, struct file *file)
95{
96 spin_lock(&xen_mce_chrdev_state_lock);
97
98 xen_mce_chrdev_open_count--;
99 xen_mce_chrdev_open_exclu = 0;
100
101 spin_unlock(&xen_mce_chrdev_state_lock);
102
103 return 0;
104}
105
106static ssize_t xen_mce_chrdev_read(struct file *filp, char __user *ubuf,
107 size_t usize, loff_t *off)
108{
109 char __user *buf = ubuf;
110 unsigned num;
111 int i, err;
112
113 mutex_lock(&mcelog_lock);
114
115 num = xen_mcelog.next;
116
117
118 err = -EINVAL;
119 if (*off != 0 || usize < XEN_MCE_LOG_LEN*sizeof(struct xen_mce))
120 goto out;
121
122 err = 0;
123 for (i = 0; i < num; i++) {
124 struct xen_mce *m = &xen_mcelog.entry[i];
125
126 err |= copy_to_user(buf, m, sizeof(*m));
127 buf += sizeof(*m);
128 }
129
130 memset(xen_mcelog.entry, 0, num * sizeof(struct xen_mce));
131 xen_mcelog.next = 0;
132
133 if (err)
134 err = -EFAULT;
135
136out:
137 mutex_unlock(&mcelog_lock);
138
139 return err ? err : buf - ubuf;
140}
141
142static unsigned int xen_mce_chrdev_poll(struct file *file, poll_table *wait)
143{
144 poll_wait(file, &xen_mce_chrdev_wait, wait);
145
146 if (xen_mcelog.next)
147 return POLLIN | POLLRDNORM;
148
149 return 0;
150}
151
152static long xen_mce_chrdev_ioctl(struct file *f, unsigned int cmd,
153 unsigned long arg)
154{
155 int __user *p = (int __user *)arg;
156
157 if (!capable(CAP_SYS_ADMIN))
158 return -EPERM;
159
160 switch (cmd) {
161 case MCE_GET_RECORD_LEN:
162 return put_user(sizeof(struct xen_mce), p);
163 case MCE_GET_LOG_LEN:
164 return put_user(XEN_MCE_LOG_LEN, p);
165 case MCE_GETCLEAR_FLAGS: {
166 unsigned flags;
167
168 do {
169 flags = xen_mcelog.flags;
170 } while (cmpxchg(&xen_mcelog.flags, flags, 0) != flags);
171
172 return put_user(flags, p);
173 }
174 default:
175 return -ENOTTY;
176 }
177}
178
179static const struct file_operations xen_mce_chrdev_ops = {
180 .open = xen_mce_chrdev_open,
181 .release = xen_mce_chrdev_release,
182 .read = xen_mce_chrdev_read,
183 .poll = xen_mce_chrdev_poll,
184 .unlocked_ioctl = xen_mce_chrdev_ioctl,
185 .llseek = no_llseek,
186};
187
188static struct miscdevice xen_mce_chrdev_device = {
189 MISC_MCELOG_MINOR,
190 "mcelog",
191 &xen_mce_chrdev_ops,
192};
193
194
195
196
197static void xen_mce_log(struct xen_mce *mce)
198{
199 unsigned entry;
200
201 entry = xen_mcelog.next;
202
203
204
205
206
207
208 if (entry >= XEN_MCE_LOG_LEN) {
209 set_bit(XEN_MCE_OVERFLOW,
210 (unsigned long *)&xen_mcelog.flags);
211 return;
212 }
213
214 memcpy(xen_mcelog.entry + entry, mce, sizeof(struct xen_mce));
215
216 xen_mcelog.next++;
217}
218
219static int convert_log(struct mc_info *mi)
220{
221 struct mcinfo_common *mic;
222 struct mcinfo_global *mc_global;
223 struct mcinfo_bank *mc_bank;
224 struct xen_mce m;
225 uint32_t i;
226
227 mic = NULL;
228 x86_mcinfo_lookup(&mic, mi, MC_TYPE_GLOBAL);
229 if (unlikely(!mic)) {
230 pr_warning(XEN_MCELOG "Failed to find global error info\n");
231 return -ENODEV;
232 }
233
234 memset(&m, 0, sizeof(struct xen_mce));
235
236 mc_global = (struct mcinfo_global *)mic;
237 m.mcgstatus = mc_global->mc_gstatus;
238 m.apicid = mc_global->mc_apicid;
239
240 for (i = 0; i < ncpus; i++)
241 if (g_physinfo[i].mc_apicid == m.apicid)
242 break;
243 if (unlikely(i == ncpus)) {
244 pr_warning(XEN_MCELOG "Failed to match cpu with apicid %d\n",
245 m.apicid);
246 return -ENODEV;
247 }
248
249 m.socketid = g_physinfo[i].mc_chipid;
250 m.cpu = m.extcpu = g_physinfo[i].mc_cpunr;
251 m.cpuvendor = (__u8)g_physinfo[i].mc_vendor;
252 m.mcgcap = g_physinfo[i].mc_msrvalues[__MC_MSR_MCGCAP].value;
253
254 mic = NULL;
255 x86_mcinfo_lookup(&mic, mi, MC_TYPE_BANK);
256 if (unlikely(!mic)) {
257 pr_warning(XEN_MCELOG "Fail to find bank error info\n");
258 return -ENODEV;
259 }
260
261 do {
262 if ((!mic) || (mic->size == 0) ||
263 (mic->type != MC_TYPE_GLOBAL &&
264 mic->type != MC_TYPE_BANK &&
265 mic->type != MC_TYPE_EXTENDED &&
266 mic->type != MC_TYPE_RECOVERY))
267 break;
268
269 if (mic->type == MC_TYPE_BANK) {
270 mc_bank = (struct mcinfo_bank *)mic;
271 m.misc = mc_bank->mc_misc;
272 m.status = mc_bank->mc_status;
273 m.addr = mc_bank->mc_addr;
274 m.tsc = mc_bank->mc_tsc;
275 m.bank = mc_bank->mc_bank;
276 m.finished = 1;
277
278 xen_mce_log(&m);
279 }
280 mic = x86_mcinfo_next(mic);
281 } while (1);
282
283 return 0;
284}
285
286static int mc_queue_handle(uint32_t flags)
287{
288 struct xen_mc mc_op;
289 int ret = 0;
290
291 mc_op.cmd = XEN_MC_fetch;
292 mc_op.interface_version = XEN_MCA_INTERFACE_VERSION;
293 set_xen_guest_handle(mc_op.u.mc_fetch.data, &g_mi);
294 do {
295 mc_op.u.mc_fetch.flags = flags;
296 ret = HYPERVISOR_mca(&mc_op);
297 if (ret) {
298 pr_err(XEN_MCELOG "Failed to fetch %s error log\n",
299 (flags == XEN_MC_URGENT) ?
300 "urgnet" : "nonurgent");
301 break;
302 }
303
304 if (mc_op.u.mc_fetch.flags & XEN_MC_NODATA ||
305 mc_op.u.mc_fetch.flags & XEN_MC_FETCHFAILED)
306 break;
307 else {
308 ret = convert_log(&g_mi);
309 if (ret)
310 pr_warning(XEN_MCELOG
311 "Failed to convert this error log, "
312 "continue acking it anyway\n");
313
314 mc_op.u.mc_fetch.flags = flags | XEN_MC_ACK;
315 ret = HYPERVISOR_mca(&mc_op);
316 if (ret) {
317 pr_err(XEN_MCELOG
318 "Failed to ack previous error log\n");
319 break;
320 }
321 }
322 } while (1);
323
324 return ret;
325}
326
327
328static void xen_mce_work_fn(struct work_struct *work)
329{
330 int err;
331
332 mutex_lock(&mcelog_lock);
333
334
335 err = mc_queue_handle(XEN_MC_URGENT);
336 if (err)
337 pr_err(XEN_MCELOG
338 "Failed to handle urgent mc_info queue, "
339 "continue handling nonurgent mc_info queue anyway.\n");
340
341
342 err = mc_queue_handle(XEN_MC_NONURGENT);
343 if (err)
344 pr_err(XEN_MCELOG
345 "Failed to handle nonurgent mc_info queue.\n");
346
347
348 wake_up_interruptible(&xen_mce_chrdev_wait);
349
350 mutex_unlock(&mcelog_lock);
351}
352static DECLARE_WORK(xen_mce_work, xen_mce_work_fn);
353
354static irqreturn_t xen_mce_interrupt(int irq, void *dev_id)
355{
356 schedule_work(&xen_mce_work);
357 return IRQ_HANDLED;
358}
359
360static int bind_virq_for_mce(void)
361{
362 int ret;
363 struct xen_mc mc_op;
364
365 memset(&mc_op, 0, sizeof(struct xen_mc));
366
367
368 mc_op.cmd = XEN_MC_physcpuinfo;
369 mc_op.interface_version = XEN_MCA_INTERFACE_VERSION;
370 set_xen_guest_handle(mc_op.u.mc_physcpuinfo.info, g_physinfo);
371 ret = HYPERVISOR_mca(&mc_op);
372 if (ret) {
373 pr_err(XEN_MCELOG "Failed to get CPU numbers\n");
374 return ret;
375 }
376
377
378 ncpus = mc_op.u.mc_physcpuinfo.ncpus;
379 g_physinfo = kcalloc(ncpus, sizeof(struct mcinfo_logical_cpu),
380 GFP_KERNEL);
381 if (!g_physinfo)
382 return -ENOMEM;
383 set_xen_guest_handle(mc_op.u.mc_physcpuinfo.info, g_physinfo);
384 ret = HYPERVISOR_mca(&mc_op);
385 if (ret) {
386 pr_err(XEN_MCELOG "Failed to get CPU info\n");
387 kfree(g_physinfo);
388 return ret;
389 }
390
391 ret = bind_virq_to_irqhandler(VIRQ_MCA, 0,
392 xen_mce_interrupt, 0, "mce", NULL);
393 if (ret < 0) {
394 pr_err(XEN_MCELOG "Failed to bind virq\n");
395 kfree(g_physinfo);
396 return ret;
397 }
398
399 return 0;
400}
401
402static int __init xen_late_init_mcelog(void)
403{
404
405 if (xen_initial_domain()) {
406
407 if (misc_register(&xen_mce_chrdev_device))
408 return -ENODEV;
409 return bind_virq_for_mce();
410 }
411
412 return -ENODEV;
413}
414device_initcall(xen_late_init_mcelog);
415
