timing.c 7.1 KB

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