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 22 void 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 44 static 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 82 void 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 } 99 100 static 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 }; 128 129 static 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. */ 161 static 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 } 188 189 done: 190 return err; 191 } 192 193 static 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 } 197 198 static 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 }; 206 207 void kvmppc_create_vcpu_debugfs(struct kvm_vcpu *vcpu, unsigned int id) 208 { 209 static char dbg_fname[50]; 210 struct dentry *debugfs_file; 211 212 snprintf(dbg_fname, sizeof(dbg_fname), "vm%u_vcpu%u_timing", 213 current->pid, id); 214 debugfs_file = debugfs_create_file(dbg_fname, 0666, 215 kvm_debugfs_dir, vcpu, 216 &kvmppc_exit_timing_fops); 217 218 if (!debugfs_file) { 219 printk(KERN_ERR"%s: error creating debugfs file %s\n", 220 __func__, dbg_fname); 221 return; 222 } 223 224 vcpu->arch.debugfs_exit_timing = debugfs_file; 225 } 226 227 void kvmppc_remove_vcpu_debugfs(struct kvm_vcpu *vcpu) 228 { 229 if (vcpu->arch.debugfs_exit_timing) { 230 debugfs_remove(vcpu->arch.debugfs_exit_timing); 231 vcpu->arch.debugfs_exit_timing = NULL; 232 } 233 } 234