KVM: ppc: mostly cosmetic updates to the exit timing accounting code

The only significant changes were to kvmppc_exit_timing_write() and
kvmppc_exit_timing_show(), both of which were dramatically simplified.

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 43 insertions, 66 deletions

diff --git a/arch/powerpc/kvm/timing.c b/arch/powerpc/kvm/timing.c
index f42d2728a6a5..47ee603f558e 100644
--- a/arch/powerpc/kvm/timing.c
+++ b/arch/powerpc/kvm/timing.c
@@ -12,7 +12,7 @@
  * along with this program; if not, write to the Free Software
  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  *
- * Copyright IBM Corp. 2007
+ * Copyright IBM Corp. 2008
  *
  * Authors: Hollis Blanchard <hollisb@us.ibm.com>
  *          Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
@@ -24,10 +24,11 @@
 #include <linux/debugfs.h>
 #include <linux/uaccess.h>
 
-#include "timing.h"
 #include <asm/time.h>
 #include <asm-generic/div64.h>
 
+#include "timing.h"
+
 void kvmppc_init_timing_stats(struct kvm_vcpu *vcpu)
 {
         int i;
@@ -52,8 +53,7 @@ void kvmppc_init_timing_stats(struct kvm_vcpu *vcpu)
         local_irq_enable();
 }
 
-static void add_exit_timing(struct kvm_vcpu *vcpu,
-                                        u64 duration, int type)
+static void add_exit_timing(struct kvm_vcpu *vcpu, u64 duration, int type)
 {
         u64 old;
 
@@ -115,54 +115,46 @@ void kvmppc_update_timing_stats(struct kvm_vcpu *vcpu)
 }
 
 static const char *kvm_exit_names[__NUMBER_OF_KVM_EXIT_TYPES] = {
-        [MMIO_EXITS] =                  "MMIO",
-        [DCR_EXITS] =                   "DCR",
-        [SIGNAL_EXITS] =                "SIGNAL",
-        [ITLB_REAL_MISS_EXITS] =        "ITLBREAL",
-        [ITLB_VIRT_MISS_EXITS] =        "ITLBVIRT",
-        [DTLB_REAL_MISS_EXITS] =        "DTLBREAL",
-        [DTLB_VIRT_MISS_EXITS] =        "DTLBVIRT",
-        [SYSCALL_EXITS] =               "SYSCALL",
-        [ISI_EXITS] =                   "ISI",
-        [DSI_EXITS] =                   "DSI",
-        [EMULATED_INST_EXITS] =         "EMULINST",
-        [EMULATED_MTMSRWE_EXITS] =      "EMUL_WAIT",
-        [EMULATED_WRTEE_EXITS] =        "EMUL_WRTEE",
-        [EMULATED_MTSPR_EXITS] =        "EMUL_MTSPR",
-        [EMULATED_MFSPR_EXITS] =        "EMUL_MFSPR",
-        [EMULATED_MTMSR_EXITS] =        "EMUL_MTMSR",
-        [EMULATED_MFMSR_EXITS] =        "EMUL_MFMSR",
-        [EMULATED_TLBSX_EXITS] =        "EMUL_TLBSX",
-        [EMULATED_TLBWE_EXITS] =        "EMUL_TLBWE",
-        [EMULATED_RFI_EXITS] =          "EMUL_RFI",
-        [DEC_EXITS] =                   "DEC",
-        [EXT_INTR_EXITS] =              "EXTINT",
-        [HALT_WAKEUP] =                 "HALT",
-        [USR_PR_INST] =                 "USR_PR_INST",
-        [FP_UNAVAIL] =                  "FP_UNAVAIL",
-        [DEBUG_EXITS] =                 "DEBUG",
-        [TIMEINGUEST] =                 "TIMEINGUEST"
+        [MMIO_EXITS] =              "MMIO",
+        [DCR_EXITS] =               "DCR",
+        [SIGNAL_EXITS] =            "SIGNAL",
+        [ITLB_REAL_MISS_EXITS] =    "ITLBREAL",
+        [ITLB_VIRT_MISS_EXITS] =    "ITLBVIRT",
+        [DTLB_REAL_MISS_EXITS] =    "DTLBREAL",
+        [DTLB_VIRT_MISS_EXITS] =    "DTLBVIRT",
+        [SYSCALL_EXITS] =           "SYSCALL",
+        [ISI_EXITS] =               "ISI",
+        [DSI_EXITS] =               "DSI",
+        [EMULATED_INST_EXITS] =     "EMULINST",
+        [EMULATED_MTMSRWE_EXITS] =  "EMUL_WAIT",
+        [EMULATED_WRTEE_EXITS] =    "EMUL_WRTEE",
+        [EMULATED_MTSPR_EXITS] =    "EMUL_MTSPR",
+        [EMULATED_MFSPR_EXITS] =    "EMUL_MFSPR",
+        [EMULATED_MTMSR_EXITS] =    "EMUL_MTMSR",
+        [EMULATED_MFMSR_EXITS] =    "EMUL_MFMSR",
+        [EMULATED_TLBSX_EXITS] =    "EMUL_TLBSX",
+        [EMULATED_TLBWE_EXITS] =    "EMUL_TLBWE",
+        [EMULATED_RFI_EXITS] =      "EMUL_RFI",
+        [DEC_EXITS] =               "DEC",
+        [EXT_INTR_EXITS] =          "EXTINT",
+        [HALT_WAKEUP] =             "HALT",
+        [USR_PR_INST] =             "USR_PR_INST",
+        [FP_UNAVAIL] =              "FP_UNAVAIL",
+        [DEBUG_EXITS] =             "DEBUG",
+        [TIMEINGUEST] =             "TIMEINGUEST"
 };
 
 static int kvmppc_exit_timing_show(struct seq_file *m, void *private)
 {
         struct kvm_vcpu *vcpu = m->private;
         int i;
-        u64 min, max;
+
+        seq_printf(m, "%s", "type       count   min     max     sum     sum_squared\n");
 
         for (i = 0; i < __NUMBER_OF_KVM_EXIT_TYPES; i++) {
-                if (vcpu->arch.timing_min_duration[i] == 0xFFFFFFFF)
-                        min = 0;
-                else
-                        min = vcpu->arch.timing_min_duration[i];
-                if (vcpu->arch.timing_max_duration[i] == 0)
-                        max = 0;
-                else
-                        max = vcpu->arch.timing_max_duration[i];
-
-                seq_printf(m, "%12s: count %10d min %10lld "
-                        "max %10lld sum %20lld sum_quad %20lld\n",
-                        kvm_exit_names[i], vcpu->arch.timing_count_type[i],
+                seq_printf(m, "%12s     %10d    %10lld  %10lld  %20lld  %20lld\n",
+                        kvm_exit_names[i],
+                        vcpu->arch.timing_count_type[i],
                         vcpu->arch.timing_min_duration[i],
                         vcpu->arch.timing_max_duration[i],
                         vcpu->arch.timing_sum_duration[i],
@@ -171,31 +163,19 @@ static int kvmppc_exit_timing_show(struct seq_file *m, void *private)
         return 0;
 }
 
+/* Write 'c' to clear the timing statistics. */
 static ssize_t kvmppc_exit_timing_write(struct file *file,
                                        const char __user *user_buf,
                                        size_t count, loff_t *ppos)
 {
-        size_t len;
-        int err;
-        const char __user *p;
+        int err = -EINVAL;
         char c;
 
-        len = 0;
-        p = user_buf;
-        while (len < count) {
-                if (get_user(c, p++))
-                        err = -EFAULT;
-                if (c == 0 || c == '\n')
-                        break;
-                len++;
-        }
-
-        if (len > 1) {
-                err = -EINVAL;
+        if (count > 1) {
                 goto done;
         }
 
-        if (copy_from_user(&c, user_buf, sizeof(c))) {
+        if (get_user(c, user_buf)) {
                 err = -EFAULT;
                 goto done;
         }
@@ -203,16 +183,13 @@ static ssize_t kvmppc_exit_timing_write(struct file *file,
         if (c == 'c') {
                 struct seq_file *seqf = (struct seq_file *)file->private_data;
                 struct kvm_vcpu *vcpu = seqf->private;
-                /* write does not affect out buffers previsously generated with
-                 * show. Seq file is locked here to prevent races of init with
+                /* Write does not affect our buffers previously generated with
+                 * show. seq_file is locked here to prevent races of init with
                  * a show call */
                 mutex_lock(&seqf->lock);
                 kvmppc_init_timing_stats(vcpu);
                 mutex_unlock(&seqf->lock);
                 err = count;
-        } else {
-                err = -EINVAL;
-                goto done;
         }
 
 done:
@@ -238,7 +215,7 @@ void kvmppc_create_vcpu_debugfs(struct kvm_vcpu *vcpu, unsigned int id)
         static char dbg_fname[50];
         struct dentry *debugfs_file;
 
-        snprintf(dbg_fname, sizeof(dbg_fname), "vm%u_vcpu%03u_timing",
+        snprintf(dbg_fname, sizeof(dbg_fname), "vm%u_vcpu%u_timing",
                  current->pid, id);
         debugfs_file = debugfs_create_file(dbg_fname, 0666,
                                         kvm_debugfs_dir, vcpu,