CONFIG_FILE_LOCKING should not depend on CONFIG_BLOCK
[sfrench/cifs-2.6.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
27 #include <asm/time.h>
28 #include <asm-generic/div64.h>
29
30 #include "timing.h"
31
32 void kvmppc_init_timing_stats(struct kvm_vcpu *vcpu)
33 {
34         int i;
35
36         /* pause guest execution to avoid concurrent updates */
37         local_irq_disable();
38         mutex_lock(&vcpu->mutex);
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->mutex);
53         local_irq_enable();
54 }
55
56 static void add_exit_timing(struct kvm_vcpu *vcpu, u64 duration, int type)
57 {
58         u64 old;
59
60         do_div(duration, tb_ticks_per_usec);
61         if (unlikely(duration > 0xFFFFFFFF)) {
62                 printk(KERN_ERR"%s - duration too big -> overflow"
63                         " duration %lld type %d exit #%d\n",
64                         __func__, duration, type,
65                         vcpu->arch.timing_count_type[type]);
66                 return;
67         }
68
69         vcpu->arch.timing_count_type[type]++;
70
71         /* sum */
72         old = vcpu->arch.timing_sum_duration[type];
73         vcpu->arch.timing_sum_duration[type] += duration;
74         if (unlikely(old > vcpu->arch.timing_sum_duration[type])) {
75                 printk(KERN_ERR"%s - wrap adding sum of durations"
76                         " old %lld new %lld type %d exit # of type %d\n",
77                         __func__, old, vcpu->arch.timing_sum_duration[type],
78                         type, vcpu->arch.timing_count_type[type]);
79         }
80
81         /* square sum */
82         old = vcpu->arch.timing_sum_quad_duration[type];
83         vcpu->arch.timing_sum_quad_duration[type] += (duration*duration);
84         if (unlikely(old > vcpu->arch.timing_sum_quad_duration[type])) {
85                 printk(KERN_ERR"%s - wrap adding sum of squared durations"
86                         " old %lld new %lld type %d exit # of type %d\n",
87                         __func__, old,
88                         vcpu->arch.timing_sum_quad_duration[type],
89                         type, vcpu->arch.timing_count_type[type]);
90         }
91
92         /* set min/max */
93         if (unlikely(duration < vcpu->arch.timing_min_duration[type]))
94                 vcpu->arch.timing_min_duration[type] = duration;
95         if (unlikely(duration > vcpu->arch.timing_max_duration[type]))
96                 vcpu->arch.timing_max_duration[type] = duration;
97 }
98
99 void kvmppc_update_timing_stats(struct kvm_vcpu *vcpu)
100 {
101         u64 exit = vcpu->arch.timing_last_exit;
102         u64 enter = vcpu->arch.timing_last_enter.tv64;
103
104         /* save exit time, used next exit when the reenter time is known */
105         vcpu->arch.timing_last_exit = vcpu->arch.timing_exit.tv64;
106
107         if (unlikely(vcpu->arch.last_exit_type == 0xDEAD || exit == 0))
108                 return; /* skip incomplete cycle (e.g. after reset) */
109
110         /* update statistics for average and standard deviation */
111         add_exit_timing(vcpu, (enter - exit), vcpu->arch.last_exit_type);
112         /* enter -> timing_last_exit is time spent in guest - log this too */
113         add_exit_timing(vcpu, (vcpu->arch.timing_last_exit - enter),
114                         TIMEINGUEST);
115 }
116
117 static const char *kvm_exit_names[__NUMBER_OF_KVM_EXIT_TYPES] = {
118         [MMIO_EXITS] =              "MMIO",
119         [DCR_EXITS] =               "DCR",
120         [SIGNAL_EXITS] =            "SIGNAL",
121         [ITLB_REAL_MISS_EXITS] =    "ITLBREAL",
122         [ITLB_VIRT_MISS_EXITS] =    "ITLBVIRT",
123         [DTLB_REAL_MISS_EXITS] =    "DTLBREAL",
124         [DTLB_VIRT_MISS_EXITS] =    "DTLBVIRT",
125         [SYSCALL_EXITS] =           "SYSCALL",
126         [ISI_EXITS] =               "ISI",
127         [DSI_EXITS] =               "DSI",
128         [EMULATED_INST_EXITS] =     "EMULINST",
129         [EMULATED_MTMSRWE_EXITS] =  "EMUL_WAIT",
130         [EMULATED_WRTEE_EXITS] =    "EMUL_WRTEE",
131         [EMULATED_MTSPR_EXITS] =    "EMUL_MTSPR",
132         [EMULATED_MFSPR_EXITS] =    "EMUL_MFSPR",
133         [EMULATED_MTMSR_EXITS] =    "EMUL_MTMSR",
134         [EMULATED_MFMSR_EXITS] =    "EMUL_MFMSR",
135         [EMULATED_TLBSX_EXITS] =    "EMUL_TLBSX",
136         [EMULATED_TLBWE_EXITS] =    "EMUL_TLBWE",
137         [EMULATED_RFI_EXITS] =      "EMUL_RFI",
138         [DEC_EXITS] =               "DEC",
139         [EXT_INTR_EXITS] =          "EXTINT",
140         [HALT_WAKEUP] =             "HALT",
141         [USR_PR_INST] =             "USR_PR_INST",
142         [FP_UNAVAIL] =              "FP_UNAVAIL",
143         [DEBUG_EXITS] =             "DEBUG",
144         [TIMEINGUEST] =             "TIMEINGUEST"
145 };
146
147 static int kvmppc_exit_timing_show(struct seq_file *m, void *private)
148 {
149         struct kvm_vcpu *vcpu = m->private;
150         int i;
151
152         seq_printf(m, "%s", "type       count   min     max     sum     sum_squared\n");
153
154         for (i = 0; i < __NUMBER_OF_KVM_EXIT_TYPES; i++) {
155                 seq_printf(m, "%12s     %10d    %10lld  %10lld  %20lld  %20lld\n",
156                         kvm_exit_names[i],
157                         vcpu->arch.timing_count_type[i],
158                         vcpu->arch.timing_min_duration[i],
159                         vcpu->arch.timing_max_duration[i],
160                         vcpu->arch.timing_sum_duration[i],
161                         vcpu->arch.timing_sum_quad_duration[i]);
162         }
163         return 0;
164 }
165
166 /* Write 'c' to clear the timing statistics. */
167 static ssize_t kvmppc_exit_timing_write(struct file *file,
168                                        const char __user *user_buf,
169                                        size_t count, loff_t *ppos)
170 {
171         int err = -EINVAL;
172         char c;
173
174         if (count > 1) {
175                 goto done;
176         }
177
178         if (get_user(c, user_buf)) {
179                 err = -EFAULT;
180                 goto done;
181         }
182
183         if (c == 'c') {
184                 struct seq_file *seqf = (struct seq_file *)file->private_data;
185                 struct kvm_vcpu *vcpu = seqf->private;
186                 /* Write does not affect our buffers previously generated with
187                  * show. seq_file is locked here to prevent races of init with
188                  * a show call */
189                 mutex_lock(&seqf->lock);
190                 kvmppc_init_timing_stats(vcpu);
191                 mutex_unlock(&seqf->lock);
192                 err = count;
193         }
194
195 done:
196         return err;
197 }
198
199 static int kvmppc_exit_timing_open(struct inode *inode, struct file *file)
200 {
201         return single_open(file, kvmppc_exit_timing_show, inode->i_private);
202 }
203
204 static struct file_operations kvmppc_exit_timing_fops = {
205         .owner   = THIS_MODULE,
206         .open    = kvmppc_exit_timing_open,
207         .read    = seq_read,
208         .write   = kvmppc_exit_timing_write,
209         .llseek  = seq_lseek,
210         .release = single_release,
211 };
212
213 void kvmppc_create_vcpu_debugfs(struct kvm_vcpu *vcpu, unsigned int id)
214 {
215         static char dbg_fname[50];
216         struct dentry *debugfs_file;
217
218         snprintf(dbg_fname, sizeof(dbg_fname), "vm%u_vcpu%u_timing",
219                  current->pid, id);
220         debugfs_file = debugfs_create_file(dbg_fname, 0666,
221                                         kvm_debugfs_dir, vcpu,
222                                         &kvmppc_exit_timing_fops);
223
224         if (!debugfs_file) {
225                 printk(KERN_ERR"%s: error creating debugfs file %s\n",
226                         __func__, dbg_fname);
227                 return;
228         }
229
230         vcpu->arch.debugfs_exit_timing = debugfs_file;
231 }
232
233 void kvmppc_remove_vcpu_debugfs(struct kvm_vcpu *vcpu)
234 {
235         if (vcpu->arch.debugfs_exit_timing) {
236                 debugfs_remove(vcpu->arch.debugfs_exit_timing);
237                 vcpu->arch.debugfs_exit_timing = NULL;
238         }
239 }