1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *
4 * Copyright IBM Corp. 2008
5 *
6 * Authors: Hollis Blanchard <hollisb@us.ibm.com>
7 *          Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
8 */
9
10#include <linux/kvm_host.h>
11#include <linux/fs.h>
12#include <linux/seq_file.h>
13#include <linux/debugfs.h>
14#include <linux/uaccess.h>
15#include <linux/module.h>
16
17#include <asm/time.h>
18#include <asm-generic/div64.h>
19
20#include "timing.h"
21
22void kvmppc_init_timing_stats(struct kvm_vcpu *vcpu)
23{
24	int i;
25
26	/* Take a lock to avoid concurrent updates */
27	mutex_lock(&vcpu->arch.exit_timing_lock);
28
29	vcpu->arch.last_exit_type = 0xDEAD;
30	for (i = 0; i < __NUMBER_OF_KVM_EXIT_TYPES; i++) {
31		vcpu->arch.timing_count_type[i] = 0;
32		vcpu->arch.timing_max_duration[i] = 0;
33		vcpu->arch.timing_min_duration[i] = 0xFFFFFFFF;
34		vcpu->arch.timing_sum_duration[i] = 0;
35		vcpu->arch.timing_sum_quad_duration[i] = 0;
36	}
37	vcpu->arch.timing_last_exit = 0;
38	vcpu->arch.timing_exit.tv64 = 0;
39	vcpu->arch.timing_last_enter.tv64 = 0;
40
41	mutex_unlock(&vcpu->arch.exit_timing_lock);
42}
43
44static void add_exit_timing(struct kvm_vcpu *vcpu, u64 duration, int type)
45{
46	u64 old;
47
48	mutex_lock(&vcpu->arch.exit_timing_lock);
49
50	vcpu->arch.timing_count_type[type]++;
51
52	/* sum */
53	old = vcpu->arch.timing_sum_duration[type];
54	vcpu->arch.timing_sum_duration[type] += duration;
55	if (unlikely(old > vcpu->arch.timing_sum_duration[type])) {
56		printk(KERN_ERR"%s - wrap adding sum of durations"
57			" old %lld new %lld type %d exit # of type %d\n",
58			__func__, old, vcpu->arch.timing_sum_duration[type],
59			type, vcpu->arch.timing_count_type[type]);
60	}
61
62	/* square sum */
63	old = vcpu->arch.timing_sum_quad_duration[type];
64	vcpu->arch.timing_sum_quad_duration[type] += (duration*duration);
65	if (unlikely(old > vcpu->arch.timing_sum_quad_duration[type])) {
66		printk(KERN_ERR"%s - wrap adding sum of squared durations"
67			" old %lld new %lld type %d exit # of type %d\n",
68			__func__, old,
69			vcpu->arch.timing_sum_quad_duration[type],
70			type, vcpu->arch.timing_count_type[type]);
71	}
72
73	/* set min/max */
74	if (unlikely(duration < vcpu->arch.timing_min_duration[type]))
75		vcpu->arch.timing_min_duration[type] = duration;
76	if (unlikely(duration > vcpu->arch.timing_max_duration[type]))
77		vcpu->arch.timing_max_duration[type] = duration;
78
79	mutex_unlock(&vcpu->arch.exit_timing_lock);
80}
81
82void kvmppc_update_timing_stats(struct kvm_vcpu *vcpu)
83{
84	u64 exit = vcpu->arch.timing_last_exit;
85	u64 enter = vcpu->arch.timing_last_enter.tv64;
86
87	/* save exit time, used next exit when the reenter time is known */
88	vcpu->arch.timing_last_exit = vcpu->arch.timing_exit.tv64;
89
90	if (unlikely(vcpu->arch.last_exit_type == 0xDEAD || exit == 0))
91		return; /* skip incomplete cycle (e.g. after reset) */
92
93	/* update statistics for average and standard deviation */
94	add_exit_timing(vcpu, (enter - exit), vcpu->arch.last_exit_type);
95	/* enter -> timing_last_exit is time spent in guest - log this too */
96	add_exit_timing(vcpu, (vcpu->arch.timing_last_exit - enter),
97			TIMEINGUEST);
98}
99
100static const char *kvm_exit_names[__NUMBER_OF_KVM_EXIT_TYPES] = {
101	[MMIO_EXITS] =              "MMIO",
102	[SIGNAL_EXITS] =            "SIGNAL",
103	[ITLB_REAL_MISS_EXITS] =    "ITLBREAL",
104	[ITLB_VIRT_MISS_EXITS] =    "ITLBVIRT",
105	[DTLB_REAL_MISS_EXITS] =    "DTLBREAL",
106	[DTLB_VIRT_MISS_EXITS] =    "DTLBVIRT",
107	[SYSCALL_EXITS] =           "SYSCALL",
108	[ISI_EXITS] =               "ISI",
109	[DSI_EXITS] =               "DSI",
110	[EMULATED_INST_EXITS] =     "EMULINST",
111	[EMULATED_MTMSRWE_EXITS] =  "EMUL_WAIT",
112	[EMULATED_WRTEE_EXITS] =    "EMUL_WRTEE",
113	[EMULATED_MTSPR_EXITS] =    "EMUL_MTSPR",
114	[EMULATED_MFSPR_EXITS] =    "EMUL_MFSPR",
115	[EMULATED_MTMSR_EXITS] =    "EMUL_MTMSR",
116	[EMULATED_MFMSR_EXITS] =    "EMUL_MFMSR",
117	[EMULATED_TLBSX_EXITS] =    "EMUL_TLBSX",
118	[EMULATED_TLBWE_EXITS] =    "EMUL_TLBWE",
119	[EMULATED_RFI_EXITS] =      "EMUL_RFI",
120	[DEC_EXITS] =               "DEC",
121	[EXT_INTR_EXITS] =          "EXTINT",
122	[HALT_WAKEUP] =             "HALT",
123	[USR_PR_INST] =             "USR_PR_INST",
124	[FP_UNAVAIL] =              "FP_UNAVAIL",
125	[DEBUG_EXITS] =             "DEBUG",
126	[TIMEINGUEST] =             "TIMEINGUEST"
127};
128
129static int kvmppc_exit_timing_show(struct seq_file *m, void *private)
130{
131	struct kvm_vcpu *vcpu = m->private;
132	int i;
133	u64 min, max, sum, sum_quad;
134
135	seq_puts(m, "type	count	min	max	sum	sum_squared\n");
136
137	for (i = 0; i < __NUMBER_OF_KVM_EXIT_TYPES; i++) {
138
139		min = vcpu->arch.timing_min_duration[i];
140		do_div(min, tb_ticks_per_usec);
141		max = vcpu->arch.timing_max_duration[i];
142		do_div(max, tb_ticks_per_usec);
143		sum = vcpu->arch.timing_sum_duration[i];
144		do_div(sum, tb_ticks_per_usec);
145		sum_quad = vcpu->arch.timing_sum_quad_duration[i];
146		do_div(sum_quad, tb_ticks_per_usec);
147
148		seq_printf(m, "%12s	%10d	%10lld	%10lld	%20lld	%20lld\n",
149			kvm_exit_names[i],
150			vcpu->arch.timing_count_type[i],
151			min,
152			max,
153			sum,
154			sum_quad);
155
156	}
157	return 0;
158}
159
160/* Write 'c' to clear the timing statistics. */
161static ssize_t kvmppc_exit_timing_write(struct file *file,
162				       const char __user *user_buf,
163				       size_t count, loff_t *ppos)
164{
165	int err = -EINVAL;
166	char c;
167
168	if (count > 1) {
169		goto done;
170	}
171
172	if (get_user(c, user_buf)) {
173		err = -EFAULT;
174		goto done;
175	}
176
177	if (c == 'c') {
178		struct seq_file *seqf = file->private_data;
179		struct kvm_vcpu *vcpu = seqf->private;
180		/* Write does not affect our buffers previously generated with
181		 * show. seq_file is locked here to prevent races of init with
182		 * a show call */
183		mutex_lock(&seqf->lock);
184		kvmppc_init_timing_stats(vcpu);
185		mutex_unlock(&seqf->lock);
186		err = count;
187	}
188
189done:
190	return err;
191}
192
193static int kvmppc_exit_timing_open(struct inode *inode, struct file *file)
194{
195	return single_open(file, kvmppc_exit_timing_show, inode->i_private);
196}
197
198static const struct file_operations kvmppc_exit_timing_fops = {
199	.owner   = THIS_MODULE,
200	.open    = kvmppc_exit_timing_open,
201	.read    = seq_read,
202	.write   = kvmppc_exit_timing_write,
203	.llseek  = seq_lseek,
204	.release = single_release,
205};
206
207int kvmppc_create_vcpu_debugfs_e500(struct kvm_vcpu *vcpu,
208				    struct dentry *debugfs_dentry)
209{
210	debugfs_create_file("timing", 0666, debugfs_dentry,
211			    vcpu, &kvmppc_exit_timing_fops);
212	return 0;
213}
214