summaryrefslogtreecommitdiff
path: root/arch/powerpc/kvm/timing.c
blob: ba56a5cbba97f367b9cfa11e5350b58e78d47672 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
// SPDX-License-Identifier: GPL-2.0-only
/*
 *
 * Copyright IBM Corp. 2008
 *
 * Authors: Hollis Blanchard <hollisb@us.ibm.com>
 *          Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
 */

#include <linux/kvm_host.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/module.h>

#include <asm/time.h>
#include <asm-generic/div64.h>

#include "timing.h"

void kvmppc_init_timing_stats(struct kvm_vcpu *vcpu)
{
	int i;

	/* Take a lock to avoid concurrent updates */
	mutex_lock(&vcpu->arch.exit_timing_lock);

	vcpu->arch.last_exit_type = 0xDEAD;
	for (i = 0; i < __NUMBER_OF_KVM_EXIT_TYPES; i++) {
		vcpu->arch.timing_count_type[i] = 0;
		vcpu->arch.timing_max_duration[i] = 0;
		vcpu->arch.timing_min_duration[i] = 0xFFFFFFFF;
		vcpu->arch.timing_sum_duration[i] = 0;
		vcpu->arch.timing_sum_quad_duration[i] = 0;
	}
	vcpu->arch.timing_last_exit = 0;
	vcpu->arch.timing_exit.tv64 = 0;
	vcpu->arch.timing_last_enter.tv64 = 0;

	mutex_unlock(&vcpu->arch.exit_timing_lock);
}

static void add_exit_timing(struct kvm_vcpu *vcpu, u64 duration, int type)
{
	u64 old;

	mutex_lock(&vcpu->arch.exit_timing_lock);

	vcpu->arch.timing_count_type[type]++;

	/* sum */
	old = vcpu->arch.timing_sum_duration[type];
	vcpu->arch.timing_sum_duration[type] += duration;
	if (unlikely(old > vcpu->arch.timing_sum_duration[type])) {
		printk(KERN_ERR"%s - wrap adding sum of durations"
			" old %lld new %lld type %d exit # of type %d\n",
			__func__, old, vcpu->arch.timing_sum_duration[type],
			type, vcpu->arch.timing_count_type[type]);
	}

	/* square sum */
	old = vcpu->arch.timing_sum_quad_duration[type];
	vcpu->arch.timing_sum_quad_duration[type] += (duration*duration);
	if (unlikely(old > vcpu->arch.timing_sum_quad_duration[type])) {
		printk(KERN_ERR"%s - wrap adding sum of squared durations"
			" old %lld new %lld type %d exit # of type %d\n",
			__func__, old,
			vcpu->arch.timing_sum_quad_duration[type],
			type, vcpu->arch.timing_count_type[type]);
	}

	/* set min/max */
	if (unlikely(duration < vcpu->arch.timing_min_duration[type]))
		vcpu->arch.timing_min_duration[type] = duration;
	if (unlikely(duration > vcpu->arch.timing_max_duration[type]))
		vcpu->arch.timing_max_duration[type] = duration;

	mutex_unlock(&vcpu->arch.exit_timing_lock);
}

void kvmppc_update_timing_stats(struct kvm_vcpu *vcpu)
{
	u64 exit = vcpu->arch.timing_last_exit;
	u64 enter = vcpu->arch.timing_last_enter.tv64;

	/* save exit time, used next exit when the reenter time is known */
	vcpu->arch.timing_last_exit = vcpu->arch.timing_exit.tv64;

	if (unlikely(vcpu->arch.last_exit_type == 0xDEAD || exit == 0))
		return; /* skip incomplete cycle (e.g. after reset) */

	/* update statistics for average and standard deviation */
	add_exit_timing(vcpu, (enter - exit), vcpu->arch.last_exit_type);
	/* enter -> timing_last_exit is time spent in guest - log this too */
	add_exit_timing(vcpu, (vcpu->arch.timing_last_exit - enter),
			TIMEINGUEST);
}

static const char *kvm_exit_names[__NUMBER_OF_KVM_EXIT_TYPES] = {
	[MMIO_EXITS] =              "MMIO",
	[SIGNAL_EXITS] =            "SIGNAL",
	[ITLB_REAL_MISS_EXITS] =    "ITLBREAL",
	[ITLB_VIRT_MISS_EXITS] =    "ITLBVIRT",
	[DTLB_REAL_MISS_EXITS] =    "DTLBREAL",
	[DTLB_VIRT_MISS_EXITS] =    "DTLBVIRT",
	[SYSCALL_EXITS] =           "SYSCALL",
	[ISI_EXITS] =               "ISI",
	[DSI_EXITS] =               "DSI",
	[EMULATED_INST_EXITS] =     "EMULINST",
	[EMULATED_MTMSRWE_EXITS] =  "EMUL_WAIT",
	[EMULATED_WRTEE_EXITS] =    "EMUL_WRTEE",
	[EMULATED_MTSPR_EXITS] =    "EMUL_MTSPR",
	[EMULATED_MFSPR_EXITS] =    "EMUL_MFSPR",
	[EMULATED_MTMSR_EXITS] =    "EMUL_MTMSR",
	[EMULATED_MFMSR_EXITS] =    "EMUL_MFMSR",
	[EMULATED_TLBSX_EXITS] =    "EMUL_TLBSX",
	[EMULATED_TLBWE_EXITS] =    "EMUL_TLBWE",
	[EMULATED_RFI_EXITS] =      "EMUL_RFI",
	[DEC_EXITS] =               "DEC",
	[EXT_INTR_EXITS] =          "EXTINT",
	[HALT_WAKEUP] =             "HALT",
	[USR_PR_INST] =             "USR_PR_INST",
	[FP_UNAVAIL] =              "FP_UNAVAIL",
	[DEBUG_EXITS] =             "DEBUG",
	[TIMEINGUEST] =             "TIMEINGUEST"
};

static int kvmppc_exit_timing_show(struct seq_file *m, void *private)
{
	struct kvm_vcpu *vcpu = m->private;
	int i;
	u64 min, max, sum, sum_quad;

	seq_puts(m, "type	count	min	max	sum	sum_squared\n");

	for (i = 0; i < __NUMBER_OF_KVM_EXIT_TYPES; i++) {

		min = vcpu->arch.timing_min_duration[i];
		do_div(min, tb_ticks_per_usec);
		max = vcpu->arch.timing_max_duration[i];
		do_div(max, tb_ticks_per_usec);
		sum = vcpu->arch.timing_sum_duration[i];
		do_div(sum, tb_ticks_per_usec);
		sum_quad = vcpu->arch.timing_sum_quad_duration[i];
		do_div(sum_quad, tb_ticks_per_usec);

		seq_printf(m, "%12s	%10d	%10lld	%10lld	%20lld	%20lld\n",
			kvm_exit_names[i],
			vcpu->arch.timing_count_type[i],
			min,
			max,
			sum,
			sum_quad);

	}
	return 0;
}

/* Write 'c' to clear the timing statistics. */
static ssize_t kvmppc_exit_timing_write(struct file *file,
				       const char __user *user_buf,
				       size_t count, loff_t *ppos)
{
	int err = -EINVAL;
	char c;

	if (count > 1) {
		goto done;
	}

	if (get_user(c, user_buf)) {
		err = -EFAULT;
		goto done;
	}

	if (c == 'c') {
		struct seq_file *seqf = file->private_data;
		struct kvm_vcpu *vcpu = seqf->private;
		/* Write does not affect our buffers previously generated with
		 * show. seq_file is locked here to prevent races of init with
		 * a show call */
		mutex_lock(&seqf->lock);
		kvmppc_init_timing_stats(vcpu);
		mutex_unlock(&seqf->lock);
		err = count;
	}

done:
	return err;
}

static int kvmppc_exit_timing_open(struct inode *inode, struct file *file)
{
	return single_open(file, kvmppc_exit_timing_show, inode->i_private);
}

static const struct file_operations kvmppc_exit_timing_fops = {
	.owner   = THIS_MODULE,
	.open    = kvmppc_exit_timing_open,
	.read    = seq_read,
	.write   = kvmppc_exit_timing_write,
	.llseek  = seq_lseek,
	.release = single_release,
};

void kvmppc_create_vcpu_debugfs(struct kvm_vcpu *vcpu, unsigned int id)
{
	static char dbg_fname[50];
	struct dentry *debugfs_file;

	snprintf(dbg_fname, sizeof(dbg_fname), "vm%u_vcpu%u_timing",
		 current->pid, id);
	debugfs_file = debugfs_create_file(dbg_fname, 0666, kvm_debugfs_dir,
						vcpu, &kvmppc_exit_timing_fops);

	vcpu->arch.debugfs_exit_timing = debugfs_file;
}

void kvmppc_remove_vcpu_debugfs(struct kvm_vcpu *vcpu)
{
	debugfs_remove(vcpu->arch.debugfs_exit_timing);
	vcpu->arch.debugfs_exit_timing = NULL;
}