From 8b7b31fc24968fc62be018b9932ea94263e1b586 Mon Sep 17 00:00:00 2001

From: David Hildenbrand <david@redhat.com>

Date: Tue, 17 Oct 2017 19:15:40 +0200

Subject: [PATCH 35/69] tools/kvm_stat: add option '--guest'

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RH-Author: David Hildenbrand <david@redhat.com>

Message-id: <20171017191605.2378-15-david@redhat.com>

Patchwork-id: 77323

O-Subject: [RHEL-7.5 qemu-kvm-rhev PATCH 14/39] tools/kvm_stat: add option '--guest'

Bugzilla: 1497137

RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>

RH-Acked-by: Cornelia Huck <cohuck@redhat.com>

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

RH-Acked-by: Thomas Huth <thuth@redhat.com>

Upstream-status: linux.git f9ff1087354e5e063b96a291360a8de84bea0bed

Convertion of documentation (for man page generation) to texi.

commit f9ff1087354e5e063b96a291360a8de84bea0bed

Author: Stefan Raspl <raspl@linux.vnet.ibm.com>

Date:   Fri Mar 10 13:40:13 2017 +0100

    tools/kvm_stat: add option '--guest'

    Add a new option '-g'/'--guest' to select a particular process by providing

    the QEMU guest name.

    Notes:

    - The logic to figure out the pid corresponding to the guest name might look

      scary, but works pretty reliably in practice; in the unlikely event that it

      returns add'l flukes, it will bail out and hint at using '-p' instead, no

      harm done.

    - Mixing '-g' and '-p' is possible, and the final instance specified on the

      command line is the significant one. This is consistent with current

      behavior for '-p' which, if specified multiple times, also regards the final

      instance as the significant one.

    Signed-off-by: Stefan Raspl <raspl@linux.vnet.ibm.com>

    Reviewed-by: Janosch Frank <frankja@linux.vnet.ibm.com>

    Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

Signed-off-by: David Hildenbrand <david@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 scripts/kvm/kvm_stat      | 101 +++++++++++++++++++++++++++++++++++++++++++++-

 scripts/kvm/kvm_stat.texi |   5 +++

 2 files changed, 104 insertions(+), 2 deletions(-)

diff --git a/scripts/kvm/kvm_stat b/scripts/kvm/kvm_stat

index f2a868b..f263312 100755

--- a/scripts/kvm/kvm_stat

+++ b/scripts/kvm/kvm_stat

@@ -30,6 +30,7 @@ import fcntl

 import resource

 import struct

 import re

+import subprocess

 from collections import defaultdict

 VMX_EXIT_REASONS = {

@@ -320,6 +321,30 @@ def parse_int_list(list_string):

     return integers

+def get_pid_from_gname(gname):

+    """Fuzzy function to convert guest name to QEMU process pid.

+

+    Returns a list of potential pids, can be empty if no match found.

+    Throws an exception on processing errors.

+

+    """

+    pids = []

+    try:

+        child = subprocess.Popen(['ps', '-A', '--format', 'pid,args'],

+                                 stdout=subprocess.PIPE)

+    except:

+        raise Exception

+    for line in child.stdout:

+        line = line.lstrip().split(' ', 1)

+        # perform a sanity check before calling the more expensive

+        # function to possibly extract the guest name

+        if ' -name ' in line[1] and gname == get_gname_from_pid(line[0]):

+            pids.append(int(line[0]))

+    child.stdout.close()

+

+    return pids

+

+

 def get_gname_from_pid(pid):

     """Returns the guest name for a QEMU process pid.

@@ -977,7 +1002,7 @@ class Tui(object):

             except re.error:

                 continue

-    def show_vm_selection(self):

+    def show_vm_selection_by_pid(self):

         """Draws PID selection mask.

         Asks for a pid until a valid pid or 0 has been entered.

@@ -1016,6 +1041,50 @@ class Tui(object):

                 msg = '"' + str(pid) + '": Not a valid pid'

                 continue

+    def show_vm_selection_by_guest_name(self):

+        """Draws guest selection mask.

+

+        Asks for a guest name until a valid guest name or '' is entered.

+

+        """

+        msg = ''

+        while True:

+            self.screen.erase()

+            self.screen.addstr(0, 0,

+                               'Show statistics for specific guest.',

+                               curses.A_BOLD)

+            self.screen.addstr(1, 0,

+                               'This might limit the shown data to the trace '

+                               'statistics.')

+            self.screen.addstr(5, 0, msg)

+            curses.echo()

+            self.screen.addstr(3, 0, "Guest [ENTER or guest]: ")

+            gname = self.screen.getstr()

+            curses.noecho()

+

+            if not gname:

+                self.refresh_header(0)

+                self.update_pid(0)

+                break

+            else:

+                pids = []

+                try:

+                    pids = get_pid_from_gname(gname)

+                except:

+                    msg = '"' + gname + '": Internal error while searching, ' \

+                          'use pid filter instead'

+                    continue

+                if len(pids) == 0:

+                    msg = '"' + gname + '": Not an active guest'

+                    continue

+                if len(pids) > 1:

+                    msg = '"' + gname + '": Multiple matches found, use pid ' \

+                          'filter instead'

+                    continue

+                self.refresh_header(pids[0])

+                self.update_pid(pids[0])

+                break

+

     def show_stats(self):

         """Refreshes the screen and processes user input."""

         sleeptime = DELAY_INITIAL

@@ -1035,8 +1104,11 @@ class Tui(object):

                 if char == 'f':

                     self.show_filter_selection()

                     sleeptime = DELAY_INITIAL

+                if char == 'g':

+                    self.show_vm_selection_by_guest_name()

+                    sleeptime = DELAY_INITIAL

                 if char == 'p':

-                    self.show_vm_selection()

+                    self.show_vm_selection_by_pid()

                     sleeptime = DELAY_INITIAL

             except KeyboardInterrupt:

                 break

@@ -1106,6 +1178,7 @@ Requirements:

 Interactive Commands:

    f     filter by regular expression

+   g     filter by guest name

    p     filter by PID

    q     quit

    x     toggle reporting of stats for individual child trace events

@@ -1119,6 +1192,22 @@ Press any other key to refresh statistics immediately.

             else:

                 return ""

+    def cb_guest_to_pid(option, opt, val, parser):

+        try:

+            pids = get_pid_from_gname(val)

+        except:

+            raise optparse.OptionValueError('Error while searching for guest '

+                                            '"{}", use "-p" to specify a pid '

+                                            'instead'.format(val))

+        if len(pids) == 0:

+            raise optparse.OptionValueError('No guest by the name "{}" '

+                                            'found'.format(val))

+        if len(pids) > 1:

+            raise optparse.OptionValueError('Multiple processes found (pids: '

+                                            '{}) - use "-p" to specify a pid '

+                                            'instead'.format(" ".join(pids)))

+        parser.values.pid = pids[0]

+

     optparser = optparse.OptionParser(description=description_text,

                                       formatter=PlainHelpFormatter())

     optparser.add_option('-1', '--once', '--batch',

@@ -1158,6 +1247,14 @@ Press any other key to refresh statistics immediately.

                          dest='pid',

                          help='restrict statistics to pid',

                          )

+    optparser.add_option('-g', '--guest',

+                         action='callback',

+                         type='string',

+                         dest='pid',

+                         metavar='GUEST',

+                         help='restrict statistics to guest by name',

+                         callback=cb_guest_to_pid,

+                         )

     (options, _) = optparser.parse_args(sys.argv)

     return options

diff --git a/scripts/kvm/kvm_stat.texi b/scripts/kvm/kvm_stat.texi

index 3519cf9..a8c1071 100644

--- a/scripts/kvm/kvm_stat.texi

+++ b/scripts/kvm/kvm_stat.texi

@@ -27,6 +27,9 @@ While running in regular (interactive) mode, use any of the following keys:

 @item f

 @kindex f

 filter by regular expression

+@item g

+@kindex g

+filter by guest name

 @item p

 @kindex p

 filter by PID

@@ -55,6 +58,8 @@ Press any other key to refresh statistics immediately.

   retrieve statistics from debugfs

 @item -p, --pid=@var{pid}

   limit statistics to one virtual machine (pid)

+@item -g, --guest=@var{guest_name}

+  limit statistics to one virtual machine (guest name)

 @item -f, --fields=@var{fields}

   fields to display (regex)

 @item -h, --help

-- 

1.8.3.1