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 #include <linux/module.h> 27 28 #include <asm/time.h> 29 #include <asm-generic/div64.h> 30 31 #include "timing.h" 32 33 void kvmppc_init_timing_stats(struct kvm_vcpu *vcpu) 34 { 35 int i; 36 37 /* Take a lock to avoid concurrent updates */ 38 mutex_lock(&vcpu->arch.exit_timing_lock); 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->arch.exit_timing_lock); 53 } 54 55 static void add_exit_timing(struct kvm_vcpu *vcpu, u64 duration, int type) 56 { 57 u64 old; 58 59 do_div(duration, tb_ticks_per_usec); 60 if (unlikely(duration > 0xFFFFFFFF)) { 61 printk(KERN_ERR"%s - duration too big -> overflow" 62 " duration %lld type %d exit #%d\n", 63 __func__, duration, type, 64 vcpu->arch.timing_count_type[type]); 65 return; 66 } 67 68 mutex_lock(&vcpu->arch.exit_timing_lock); 69 70 vcpu->arch.timing_count_type[type]++; 71 72 /* sum */ 73 old = vcpu->arch.timing_sum_duration[type]; 74 vcpu->arch.timing_sum_duration[type] += duration; 75 if (unlikely(old > vcpu->arch.timing_sum_duration[type])) { 76 printk(KERN_ERR"%s - wrap adding sum of durations" 77 " old %lld new %lld type %d exit # of type %d\n", 78 __func__, old, vcpu->arch.timing_sum_duration[type], 79 type, vcpu->arch.timing_count_type[type]); 80 } 81 82 /* square sum */ 83 old = vcpu->arch.timing_sum_quad_duration[type]; 84 vcpu->arch.timing_sum_quad_duration[type] += (duration*duration); 85 if (unlikely(old > vcpu->arch.timing_sum_quad_duration[type])) { 86 printk(KERN_ERR"%s - wrap adding sum of squared durations" 87 " old %lld new %lld type %d exit # of type %d\n", 88 __func__, old, 89 vcpu->arch.timing_sum_quad_duration[type], 90 type, vcpu->arch.timing_count_type[type]); 91 } 92 93 /* set min/max */ 94 if (unlikely(duration < vcpu->arch.timing_min_duration[type])) 95 vcpu->arch.timing_min_duration[type] = duration; 96 if (unlikely(duration > vcpu->arch.timing_max_duration[type])) 97 vcpu->arch.timing_max_duration[type] = duration; 98 99 mutex_unlock(&vcpu->arch.exit_timing_lock); 100 } 101 102 void kvmppc_update_timing_stats(struct kvm_vcpu *vcpu) 103 { 104 u64 exit = vcpu->arch.timing_last_exit; 105 u64 enter = vcpu->arch.timing_last_enter.tv64; 106 107 /* save exit time, used next exit when the reenter time is known */ 108 vcpu->arch.timing_last_exit = vcpu->arch.timing_exit.tv64; 109 110 if (unlikely(vcpu->arch.last_exit_type == 0xDEAD || exit == 0)) 111 return; /* skip incomplete cycle (e.g. after reset) */ 112 113 /* update statistics for average and standard deviation */ 114 add_exit_timing(vcpu, (enter - exit), vcpu->arch.last_exit_type); 115 /* enter -> timing_last_exit is time spent in guest - log this too */ 116 add_exit_timing(vcpu, (vcpu->arch.timing_last_exit - enter), 117 TIMEINGUEST); 118 } 119 120 static const char *kvm_exit_names[__NUMBER_OF_KVM_EXIT_TYPES] = { 121 [MMIO_EXITS] = "MMIO", 122 [DCR_EXITS] = "DCR", 123 [SIGNAL_EXITS] = "SIGNAL", 124 [ITLB_REAL_MISS_EXITS] = "ITLBREAL", 125 [ITLB_VIRT_MISS_EXITS] = "ITLBVIRT", 126 [DTLB_REAL_MISS_EXITS] = "DTLBREAL", 127 [DTLB_VIRT_MISS_EXITS] = "DTLBVIRT", 128 [SYSCALL_EXITS] = "SYSCALL", 129 [ISI_EXITS] = "ISI", 130 [DSI_EXITS] = "DSI", 131 [EMULATED_INST_EXITS] = "EMULINST", 132 [EMULATED_MTMSRWE_EXITS] = "EMUL_WAIT", 133 [EMULATED_WRTEE_EXITS] = "EMUL_WRTEE", 134 [EMULATED_MTSPR_EXITS] = "EMUL_MTSPR", 135 [EMULATED_MFSPR_EXITS] = "EMUL_MFSPR", 136 [EMULATED_MTMSR_EXITS] = "EMUL_MTMSR", 137 [EMULATED_MFMSR_EXITS] = "EMUL_MFMSR", 138 [EMULATED_TLBSX_EXITS] = "EMUL_TLBSX", 139 [EMULATED_TLBWE_EXITS] = "EMUL_TLBWE", 140 [EMULATED_RFI_EXITS] = "EMUL_RFI", 141 [DEC_EXITS] = "DEC", 142 [EXT_INTR_EXITS] = "EXTINT", 143 [HALT_WAKEUP] = "HALT", 144 [USR_PR_INST] = "USR_PR_INST", 145 [FP_UNAVAIL] = "FP_UNAVAIL", 146 [DEBUG_EXITS] = "DEBUG", 147 [TIMEINGUEST] = "TIMEINGUEST" 148 }; 149 150 static int kvmppc_exit_timing_show(struct seq_file *m, void *private) 151 { 152 struct kvm_vcpu *vcpu = m->private; 153 int i; 154 u64 min, max, sum, sum_quad; 155 156 seq_printf(m, "%s", "type count min max sum sum_squared\n"); 157 158 159 for (i = 0; i < __NUMBER_OF_KVM_EXIT_TYPES; i++) { 160 161 min = vcpu->arch.timing_min_duration[i]; 162 do_div(min, tb_ticks_per_usec); 163 max = vcpu->arch.timing_max_duration[i]; 164 do_div(max, tb_ticks_per_usec); 165 sum = vcpu->arch.timing_sum_duration[i]; 166 do_div(sum, tb_ticks_per_usec); 167 sum_quad = vcpu->arch.timing_sum_quad_duration[i]; 168 do_div(sum_quad, tb_ticks_per_usec); 169 170 seq_printf(m, "%12s %10d %10lld %10lld %20lld %20lld\n", 171 kvm_exit_names[i], 172 vcpu->arch.timing_count_type[i], 173 min, 174 max, 175 sum, 176 sum_quad); 177 178 } 179 return 0; 180 } 181 182 /* Write 'c' to clear the timing statistics. */ 183 static ssize_t kvmppc_exit_timing_write(struct file *file, 184 const char __user *user_buf, 185 size_t count, loff_t *ppos) 186 { 187 int err = -EINVAL; 188 char c; 189 190 if (count > 1) { 191 goto done; 192 } 193 194 if (get_user(c, user_buf)) { 195 err = -EFAULT; 196 goto done; 197 } 198 199 if (c == 'c') { 200 struct seq_file *seqf = file->private_data; 201 struct kvm_vcpu *vcpu = seqf->private; 202 /* Write does not affect our buffers previously generated with 203 * show. seq_file is locked here to prevent races of init with 204 * a show call */ 205 mutex_lock(&seqf->lock); 206 kvmppc_init_timing_stats(vcpu); 207 mutex_unlock(&seqf->lock); 208 err = count; 209 } 210 211 done: 212 return err; 213 } 214 215 static int kvmppc_exit_timing_open(struct inode *inode, struct file *file) 216 { 217 return single_open(file, kvmppc_exit_timing_show, inode->i_private); 218 } 219 220 static const struct file_operations kvmppc_exit_timing_fops = { 221 .owner = THIS_MODULE, 222 .open = kvmppc_exit_timing_open, 223 .read = seq_read, 224 .write = kvmppc_exit_timing_write, 225 .llseek = seq_lseek, 226 .release = single_release, 227 }; 228 229 void kvmppc_create_vcpu_debugfs(struct kvm_vcpu *vcpu, unsigned int id) 230 { 231 static char dbg_fname[50]; 232 struct dentry *debugfs_file; 233 234 snprintf(dbg_fname, sizeof(dbg_fname), "vm%u_vcpu%u_timing", 235 current->pid, id); 236 debugfs_file = debugfs_create_file(dbg_fname, 0666, 237 kvm_debugfs_dir, vcpu, 238 &kvmppc_exit_timing_fops); 239 240 if (!debugfs_file) { 241 printk(KERN_ERR"%s: error creating debugfs file %s\n", 242 __func__, dbg_fname); 243 return; 244 } 245 246 vcpu->arch.debugfs_exit_timing = debugfs_file; 247 } 248 249 void kvmppc_remove_vcpu_debugfs(struct kvm_vcpu *vcpu) 250 { 251 if (vcpu->arch.debugfs_exit_timing) { 252 debugfs_remove(vcpu->arch.debugfs_exit_timing); 253 vcpu->arch.debugfs_exit_timing = NULL; 254 } 255 } 256