xref: /linux/arch/x86/kvm/debugfs.c (revision 3c4fc7bf4c9e66fe71abcbf93f62f4ddb89b7f15)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Kernel-based Virtual Machine driver for Linux
4  *
5  * Copyright 2016 Red Hat, Inc. and/or its affiliates.
6  */
7 #include <linux/kvm_host.h>
8 #include <linux/debugfs.h>
9 #include "lapic.h"
10 #include "mmu.h"
11 #include "mmu/mmu_internal.h"
12 
13 static int vcpu_get_timer_advance_ns(void *data, u64 *val)
14 {
15 	struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
16 	*val = vcpu->arch.apic->lapic_timer.timer_advance_ns;
17 	return 0;
18 }
19 
20 DEFINE_SIMPLE_ATTRIBUTE(vcpu_timer_advance_ns_fops, vcpu_get_timer_advance_ns, NULL, "%llu\n");
21 
22 static int vcpu_get_guest_mode(void *data, u64 *val)
23 {
24 	struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
25 	*val = vcpu->stat.guest_mode;
26 	return 0;
27 }
28 
29 DEFINE_SIMPLE_ATTRIBUTE(vcpu_guest_mode_fops, vcpu_get_guest_mode, NULL, "%lld\n");
30 
31 static int vcpu_get_tsc_offset(void *data, u64 *val)
32 {
33 	struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
34 	*val = vcpu->arch.tsc_offset;
35 	return 0;
36 }
37 
38 DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_offset_fops, vcpu_get_tsc_offset, NULL, "%lld\n");
39 
40 static int vcpu_get_tsc_scaling_ratio(void *data, u64 *val)
41 {
42 	struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
43 	*val = vcpu->arch.tsc_scaling_ratio;
44 	return 0;
45 }
46 
47 DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_scaling_fops, vcpu_get_tsc_scaling_ratio, NULL, "%llu\n");
48 
49 static int vcpu_get_tsc_scaling_frac_bits(void *data, u64 *val)
50 {
51 	*val = kvm_caps.tsc_scaling_ratio_frac_bits;
52 	return 0;
53 }
54 
55 DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_scaling_frac_fops, vcpu_get_tsc_scaling_frac_bits, NULL, "%llu\n");
56 
57 void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu, struct dentry *debugfs_dentry)
58 {
59 	debugfs_create_file("guest_mode", 0444, debugfs_dentry, vcpu,
60 			    &vcpu_guest_mode_fops);
61 	debugfs_create_file("tsc-offset", 0444, debugfs_dentry, vcpu,
62 			    &vcpu_tsc_offset_fops);
63 
64 	if (lapic_in_kernel(vcpu))
65 		debugfs_create_file("lapic_timer_advance_ns", 0444,
66 				    debugfs_dentry, vcpu,
67 				    &vcpu_timer_advance_ns_fops);
68 
69 	if (kvm_caps.has_tsc_control) {
70 		debugfs_create_file("tsc-scaling-ratio", 0444,
71 				    debugfs_dentry, vcpu,
72 				    &vcpu_tsc_scaling_fops);
73 		debugfs_create_file("tsc-scaling-ratio-frac-bits", 0444,
74 				    debugfs_dentry, vcpu,
75 				    &vcpu_tsc_scaling_frac_fops);
76 	}
77 }
78 
79 /*
80  * This covers statistics <1024 (11=log(1024)+1), which should be enough to
81  * cover RMAP_RECYCLE_THRESHOLD.
82  */
83 #define  RMAP_LOG_SIZE  11
84 
85 static const char *kvm_lpage_str[KVM_NR_PAGE_SIZES] = { "4K", "2M", "1G" };
86 
87 static int kvm_mmu_rmaps_stat_show(struct seq_file *m, void *v)
88 {
89 	struct kvm_rmap_head *rmap;
90 	struct kvm *kvm = m->private;
91 	struct kvm_memory_slot *slot;
92 	struct kvm_memslots *slots;
93 	unsigned int lpage_size, index;
94 	/* Still small enough to be on the stack */
95 	unsigned int *log[KVM_NR_PAGE_SIZES], *cur;
96 	int i, j, k, l, ret;
97 
98 	if (!kvm_memslots_have_rmaps(kvm))
99 		return 0;
100 
101 	ret = -ENOMEM;
102 	memset(log, 0, sizeof(log));
103 	for (i = 0; i < KVM_NR_PAGE_SIZES; i++) {
104 		log[i] = kcalloc(RMAP_LOG_SIZE, sizeof(unsigned int), GFP_KERNEL);
105 		if (!log[i])
106 			goto out;
107 	}
108 
109 	mutex_lock(&kvm->slots_lock);
110 	write_lock(&kvm->mmu_lock);
111 
112 	for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
113 		int bkt;
114 
115 		slots = __kvm_memslots(kvm, i);
116 		kvm_for_each_memslot(slot, bkt, slots)
117 			for (k = 0; k < KVM_NR_PAGE_SIZES; k++) {
118 				rmap = slot->arch.rmap[k];
119 				lpage_size = kvm_mmu_slot_lpages(slot, k + 1);
120 				cur = log[k];
121 				for (l = 0; l < lpage_size; l++) {
122 					index = ffs(pte_list_count(&rmap[l]));
123 					if (WARN_ON_ONCE(index >= RMAP_LOG_SIZE))
124 						index = RMAP_LOG_SIZE - 1;
125 					cur[index]++;
126 				}
127 			}
128 	}
129 
130 	write_unlock(&kvm->mmu_lock);
131 	mutex_unlock(&kvm->slots_lock);
132 
133 	/* index=0 counts no rmap; index=1 counts 1 rmap */
134 	seq_printf(m, "Rmap_Count:\t0\t1\t");
135 	for (i = 2; i < RMAP_LOG_SIZE; i++) {
136 		j = 1 << (i - 1);
137 		k = (1 << i) - 1;
138 		seq_printf(m, "%d-%d\t", j, k);
139 	}
140 	seq_printf(m, "\n");
141 
142 	for (i = 0; i < KVM_NR_PAGE_SIZES; i++) {
143 		seq_printf(m, "Level=%s:\t", kvm_lpage_str[i]);
144 		cur = log[i];
145 		for (j = 0; j < RMAP_LOG_SIZE; j++)
146 			seq_printf(m, "%d\t", cur[j]);
147 		seq_printf(m, "\n");
148 	}
149 
150 	ret = 0;
151 out:
152 	for (i = 0; i < KVM_NR_PAGE_SIZES; i++)
153 		kfree(log[i]);
154 
155 	return ret;
156 }
157 
158 static int kvm_mmu_rmaps_stat_open(struct inode *inode, struct file *file)
159 {
160 	struct kvm *kvm = inode->i_private;
161 
162 	if (!kvm_get_kvm_safe(kvm))
163 		return -ENOENT;
164 
165 	return single_open(file, kvm_mmu_rmaps_stat_show, kvm);
166 }
167 
168 static int kvm_mmu_rmaps_stat_release(struct inode *inode, struct file *file)
169 {
170 	struct kvm *kvm = inode->i_private;
171 
172 	kvm_put_kvm(kvm);
173 
174 	return single_release(inode, file);
175 }
176 
177 static const struct file_operations mmu_rmaps_stat_fops = {
178 	.open		= kvm_mmu_rmaps_stat_open,
179 	.read		= seq_read,
180 	.llseek		= seq_lseek,
181 	.release	= kvm_mmu_rmaps_stat_release,
182 };
183 
184 int kvm_arch_create_vm_debugfs(struct kvm *kvm)
185 {
186 	debugfs_create_file("mmu_rmaps_stat", 0644, kvm->debugfs_dentry, kvm,
187 			    &mmu_rmaps_stat_fops);
188 	return 0;
189 }
190