GNU Linux-libre 4.14.266-gnu1
[releases.git] / arch / powerpc / kvm / timing.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. 2008
16  *
17  * Authors: Hollis Blanchard <hollisb@us.ibm.com>
18  *          Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
19  */
20
21 #include <linux/kvm_host.h>
22 #include <linux/fs.h>
23 #include <linux/seq_file.h>
24 #include <linux/debugfs.h>
25 #include <linux/uaccess.h>
26 #include <linux/module.h>
27
28 #include <asm/time.h>
29 #include <asm-generic/div64.h>
30
31 #include "timing.h"
32
33 void kvmppc_init_timing_stats(struct kvm_vcpu *vcpu)
34 {
35         int i;
36
37         /* Take a lock to avoid concurrent updates */
38         mutex_lock(&vcpu->arch.exit_timing_lock);
39
40         vcpu->arch.last_exit_type = 0xDEAD;
41         for (i = 0; i < __NUMBER_OF_KVM_EXIT_TYPES; i++) {
42                 vcpu->arch.timing_count_type[i] = 0;
43                 vcpu->arch.timing_max_duration[i] = 0;
44                 vcpu->arch.timing_min_duration[i] = 0xFFFFFFFF;
45                 vcpu->arch.timing_sum_duration[i] = 0;
46                 vcpu->arch.timing_sum_quad_duration[i] = 0;
47         }
48         vcpu->arch.timing_last_exit = 0;
49         vcpu->arch.timing_exit.tv64 = 0;
50         vcpu->arch.timing_last_enter.tv64 = 0;
51
52         mutex_unlock(&vcpu->arch.exit_timing_lock);
53 }
54
55 static void add_exit_timing(struct kvm_vcpu *vcpu, u64 duration, int type)
56 {
57         u64 old;
58
59         mutex_lock(&vcpu->arch.exit_timing_lock);
60
61         vcpu->arch.timing_count_type[type]++;
62
63         /* sum */
64         old = vcpu->arch.timing_sum_duration[type];
65         vcpu->arch.timing_sum_duration[type] += duration;
66         if (unlikely(old > vcpu->arch.timing_sum_duration[type])) {
67                 printk(KERN_ERR"%s - wrap adding sum of durations"
68                         " old %lld new %lld type %d exit # of type %d\n",
69                         __func__, old, vcpu->arch.timing_sum_duration[type],
70                         type, vcpu->arch.timing_count_type[type]);
71         }
72
73         /* square sum */
74         old = vcpu->arch.timing_sum_quad_duration[type];
75         vcpu->arch.timing_sum_quad_duration[type] += (duration*duration);
76         if (unlikely(old > vcpu->arch.timing_sum_quad_duration[type])) {
77                 printk(KERN_ERR"%s - wrap adding sum of squared durations"
78                         " old %lld new %lld type %d exit # of type %d\n",
79                         __func__, old,
80                         vcpu->arch.timing_sum_quad_duration[type],
81                         type, vcpu->arch.timing_count_type[type]);
82         }
83
84         /* set min/max */
85         if (unlikely(duration < vcpu->arch.timing_min_duration[type]))
86                 vcpu->arch.timing_min_duration[type] = duration;
87         if (unlikely(duration > vcpu->arch.timing_max_duration[type]))
88                 vcpu->arch.timing_max_duration[type] = duration;
89
90         mutex_unlock(&vcpu->arch.exit_timing_lock);
91 }
92
93 void kvmppc_update_timing_stats(struct kvm_vcpu *vcpu)
94 {
95         u64 exit = vcpu->arch.timing_last_exit;
96         u64 enter = vcpu->arch.timing_last_enter.tv64;
97
98         /* save exit time, used next exit when the reenter time is known */
99         vcpu->arch.timing_last_exit = vcpu->arch.timing_exit.tv64;
100
101         if (unlikely(vcpu->arch.last_exit_type == 0xDEAD || exit == 0))
102                 return; /* skip incomplete cycle (e.g. after reset) */
103
104         /* update statistics for average and standard deviation */
105         add_exit_timing(vcpu, (enter - exit), vcpu->arch.last_exit_type);
106         /* enter -> timing_last_exit is time spent in guest - log this too */
107         add_exit_timing(vcpu, (vcpu->arch.timing_last_exit - enter),
108                         TIMEINGUEST);
109 }
110
111 static const char *kvm_exit_names[__NUMBER_OF_KVM_EXIT_TYPES] = {
112         [MMIO_EXITS] =              "MMIO",
113         [SIGNAL_EXITS] =            "SIGNAL",
114         [ITLB_REAL_MISS_EXITS] =    "ITLBREAL",
115         [ITLB_VIRT_MISS_EXITS] =    "ITLBVIRT",
116         [DTLB_REAL_MISS_EXITS] =    "DTLBREAL",
117         [DTLB_VIRT_MISS_EXITS] =    "DTLBVIRT",
118         [SYSCALL_EXITS] =           "SYSCALL",
119         [ISI_EXITS] =               "ISI",
120         [DSI_EXITS] =               "DSI",
121         [EMULATED_INST_EXITS] =     "EMULINST",
122         [EMULATED_MTMSRWE_EXITS] =  "EMUL_WAIT",
123         [EMULATED_WRTEE_EXITS] =    "EMUL_WRTEE",
124         [EMULATED_MTSPR_EXITS] =    "EMUL_MTSPR",
125         [EMULATED_MFSPR_EXITS] =    "EMUL_MFSPR",
126         [EMULATED_MTMSR_EXITS] =    "EMUL_MTMSR",
127         [EMULATED_MFMSR_EXITS] =    "EMUL_MFMSR",
128         [EMULATED_TLBSX_EXITS] =    "EMUL_TLBSX",
129         [EMULATED_TLBWE_EXITS] =    "EMUL_TLBWE",
130         [EMULATED_RFI_EXITS] =      "EMUL_RFI",
131         [DEC_EXITS] =               "DEC",
132         [EXT_INTR_EXITS] =          "EXTINT",
133         [HALT_WAKEUP] =             "HALT",
134         [USR_PR_INST] =             "USR_PR_INST",
135         [FP_UNAVAIL] =              "FP_UNAVAIL",
136         [DEBUG_EXITS] =             "DEBUG",
137         [TIMEINGUEST] =             "TIMEINGUEST"
138 };
139
140 static int kvmppc_exit_timing_show(struct seq_file *m, void *private)
141 {
142         struct kvm_vcpu *vcpu = m->private;
143         int i;
144         u64 min, max, sum, sum_quad;
145
146         seq_printf(m, "%s", "type       count   min     max     sum     sum_squared\n");
147
148
149         for (i = 0; i < __NUMBER_OF_KVM_EXIT_TYPES; i++) {
150
151                 min = vcpu->arch.timing_min_duration[i];
152                 do_div(min, tb_ticks_per_usec);
153                 max = vcpu->arch.timing_max_duration[i];
154                 do_div(max, tb_ticks_per_usec);
155                 sum = vcpu->arch.timing_sum_duration[i];
156                 do_div(sum, tb_ticks_per_usec);
157                 sum_quad = vcpu->arch.timing_sum_quad_duration[i];
158                 do_div(sum_quad, tb_ticks_per_usec);
159
160                 seq_printf(m, "%12s     %10d    %10lld  %10lld  %20lld  %20lld\n",
161                         kvm_exit_names[i],
162                         vcpu->arch.timing_count_type[i],
163                         min,
164                         max,
165                         sum,
166                         sum_quad);
167
168         }
169         return 0;
170 }
171
172 /* Write 'c' to clear the timing statistics. */
173 static ssize_t kvmppc_exit_timing_write(struct file *file,
174                                        const char __user *user_buf,
175                                        size_t count, loff_t *ppos)
176 {
177         int err = -EINVAL;
178         char c;
179
180         if (count > 1) {
181                 goto done;
182         }
183
184         if (get_user(c, user_buf)) {
185                 err = -EFAULT;
186                 goto done;
187         }
188
189         if (c == 'c') {
190                 struct seq_file *seqf = file->private_data;
191                 struct kvm_vcpu *vcpu = seqf->private;
192                 /* Write does not affect our buffers previously generated with
193                  * show. seq_file is locked here to prevent races of init with
194                  * a show call */
195                 mutex_lock(&seqf->lock);
196                 kvmppc_init_timing_stats(vcpu);
197                 mutex_unlock(&seqf->lock);
198                 err = count;
199         }
200
201 done:
202         return err;
203 }
204
205 static int kvmppc_exit_timing_open(struct inode *inode, struct file *file)
206 {
207         return single_open(file, kvmppc_exit_timing_show, inode->i_private);
208 }
209
210 static const struct file_operations kvmppc_exit_timing_fops = {
211         .owner   = THIS_MODULE,
212         .open    = kvmppc_exit_timing_open,
213         .read    = seq_read,
214         .write   = kvmppc_exit_timing_write,
215         .llseek  = seq_lseek,
216         .release = single_release,
217 };
218
219 void kvmppc_create_vcpu_debugfs(struct kvm_vcpu *vcpu, unsigned int id)
220 {
221         static char dbg_fname[50];
222         struct dentry *debugfs_file;
223
224         snprintf(dbg_fname, sizeof(dbg_fname), "vm%u_vcpu%u_timing",
225                  current->pid, id);
226         debugfs_file = debugfs_create_file(dbg_fname, 0666,
227                                         kvm_debugfs_dir, vcpu,
228                                         &kvmppc_exit_timing_fops);
229
230         if (!debugfs_file) {
231                 printk(KERN_ERR"%s: error creating debugfs file %s\n",
232                         __func__, dbg_fname);
233                 return;
234         }
235
236         vcpu->arch.debugfs_exit_timing = debugfs_file;
237 }
238
239 void kvmppc_remove_vcpu_debugfs(struct kvm_vcpu *vcpu)
240 {
241         if (vcpu->arch.debugfs_exit_timing) {
242                 debugfs_remove(vcpu->arch.debugfs_exit_timing);
243                 vcpu->arch.debugfs_exit_timing = NULL;
244         }
245 }