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-rw-r--r--arch/powerpc/kvm/timing.c239
1 files changed, 239 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/timing.c b/arch/powerpc/kvm/timing.c
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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
32void 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
56static 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
99void 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
117static 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
147static 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. */
167static 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
195done:
196 return err;
197}
198
199static 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
204static 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
213void 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
233void 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}
generated by cgit v1.2.2 (git 2.25.0) at 2025-01-12 00:07:32 -0500