Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
[linux-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 #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         [DCR_EXITS] =               "DCR",
114         [SIGNAL_EXITS] =            "SIGNAL",
115         [ITLB_REAL_MISS_EXITS] =    "ITLBREAL",
116         [ITLB_VIRT_MISS_EXITS] =    "ITLBVIRT",
117         [DTLB_REAL_MISS_EXITS] =    "DTLBREAL",
118         [DTLB_VIRT_MISS_EXITS] =    "DTLBVIRT",
119         [SYSCALL_EXITS] =           "SYSCALL",
120         [ISI_EXITS] =               "ISI",
121         [DSI_EXITS] =               "DSI",
122         [EMULATED_INST_EXITS] =     "EMULINST",
123         [EMULATED_MTMSRWE_EXITS] =  "EMUL_WAIT",
124         [EMULATED_WRTEE_EXITS] =    "EMUL_WRTEE",
125         [EMULATED_MTSPR_EXITS] =    "EMUL_MTSPR",
126         [EMULATED_MFSPR_EXITS] =    "EMUL_MFSPR",
127         [EMULATED_MTMSR_EXITS] =    "EMUL_MTMSR",
128         [EMULATED_MFMSR_EXITS] =    "EMUL_MFMSR",
129         [EMULATED_TLBSX_EXITS] =    "EMUL_TLBSX",
130         [EMULATED_TLBWE_EXITS] =    "EMUL_TLBWE",
131         [EMULATED_RFI_EXITS] =      "EMUL_RFI",
132         [DEC_EXITS] =               "DEC",
133         [EXT_INTR_EXITS] =          "EXTINT",
134         [HALT_WAKEUP] =             "HALT",
135         [USR_PR_INST] =             "USR_PR_INST",
136         [FP_UNAVAIL] =              "FP_UNAVAIL",
137         [DEBUG_EXITS] =             "DEBUG",
138         [TIMEINGUEST] =             "TIMEINGUEST"
139 };
140
141 static int kvmppc_exit_timing_show(struct seq_file *m, void *private)
142 {
143         struct kvm_vcpu *vcpu = m->private;
144         int i;
145         u64 min, max, sum, sum_quad;
146
147         seq_printf(m, "%s", "type       count   min     max     sum     sum_squared\n");
148
149
150         for (i = 0; i < __NUMBER_OF_KVM_EXIT_TYPES; i++) {
151
152                 min = vcpu->arch.timing_min_duration[i];
153                 do_div(min, tb_ticks_per_usec);
154                 max = vcpu->arch.timing_max_duration[i];
155                 do_div(max, tb_ticks_per_usec);
156                 sum = vcpu->arch.timing_sum_duration[i];
157                 do_div(sum, tb_ticks_per_usec);
158                 sum_quad = vcpu->arch.timing_sum_quad_duration[i];
159                 do_div(sum_quad, tb_ticks_per_usec);
160
161                 seq_printf(m, "%12s     %10d    %10lld  %10lld  %20lld  %20lld\n",
162                         kvm_exit_names[i],
163                         vcpu->arch.timing_count_type[i],
164                         min,
165                         max,
166                         sum,
167                         sum_quad);
168
169         }
170         return 0;
171 }
172
173 /* Write 'c' to clear the timing statistics. */
174 static ssize_t kvmppc_exit_timing_write(struct file *file,
175                                        const char __user *user_buf,
176                                        size_t count, loff_t *ppos)
177 {
178         int err = -EINVAL;
179         char c;
180
181         if (count > 1) {
182                 goto done;
183         }
184
185         if (get_user(c, user_buf)) {
186                 err = -EFAULT;
187                 goto done;
188         }
189
190         if (c == 'c') {
191                 struct seq_file *seqf = file->private_data;
192                 struct kvm_vcpu *vcpu = seqf->private;
193                 /* Write does not affect our buffers previously generated with
194                  * show. seq_file is locked here to prevent races of init with
195                  * a show call */
196                 mutex_lock(&seqf->lock);
197                 kvmppc_init_timing_stats(vcpu);
198                 mutex_unlock(&seqf->lock);
199                 err = count;
200         }
201
202 done:
203         return err;
204 }
205
206 static int kvmppc_exit_timing_open(struct inode *inode, struct file *file)
207 {
208         return single_open(file, kvmppc_exit_timing_show, inode->i_private);
209 }
210
211 static const struct file_operations kvmppc_exit_timing_fops = {
212         .owner   = THIS_MODULE,
213         .open    = kvmppc_exit_timing_open,
214         .read    = seq_read,
215         .write   = kvmppc_exit_timing_write,
216         .llseek  = seq_lseek,
217         .release = single_release,
218 };
219
220 void kvmppc_create_vcpu_debugfs(struct kvm_vcpu *vcpu, unsigned int id)
221 {
222         static char dbg_fname[50];
223         struct dentry *debugfs_file;
224
225         snprintf(dbg_fname, sizeof(dbg_fname), "vm%u_vcpu%u_timing",
226                  current->pid, id);
227         debugfs_file = debugfs_create_file(dbg_fname, 0666,
228                                         kvm_debugfs_dir, vcpu,
229                                         &kvmppc_exit_timing_fops);
230
231         if (!debugfs_file) {
232                 printk(KERN_ERR"%s: error creating debugfs file %s\n",
233                         __func__, dbg_fname);
234                 return;
235         }
236
237         vcpu->arch.debugfs_exit_timing = debugfs_file;
238 }
239
240 void kvmppc_remove_vcpu_debugfs(struct kvm_vcpu *vcpu)
241 {
242         if (vcpu->arch.debugfs_exit_timing) {
243                 debugfs_remove(vcpu->arch.debugfs_exit_timing);
244                 vcpu->arch.debugfs_exit_timing = NULL;
245         }
246 }