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
kvmppc_init_timing_stats(struct kvm_vcpu * vcpu)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
add_exit_timing(struct kvm_vcpu * vcpu,u64 duration,int type)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
kvmppc_update_timing_stats(struct kvm_vcpu * vcpu)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
kvmppc_exit_timing_show(struct seq_file * m,void * private)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. */
kvmppc_exit_timing_write(struct file * file,const char __user * user_buf,size_t count,loff_t * ppos)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
kvmppc_exit_timing_open(struct inode * inode,struct file * file)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
kvmppc_create_vcpu_debugfs(struct kvm_vcpu * vcpu,unsigned int id)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
kvmppc_remove_vcpu_debugfs(struct kvm_vcpu * vcpu)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 }
247