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@xxxxxxxxxxxxxxxxxx>
---
tools/kvm/kvm_stat/kvm_stat | 101 +++++++++++++++++++++++++++++++++++++++-
tools/kvm/kvm_stat/kvm_stat.txt | 6 +++
2 files changed, 105 insertions(+), 2 deletions(-)
diff --git a/tools/kvm/kvm_stat/kvm_stat b/tools/kvm/kvm_stat/kvm_stat
index 17d2eff..ec77aac 100755
--- a/tools/kvm/kvm_stat/kvm_stat
+++ b/tools/kvm/kvm_stat/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.
@@ -976,7 +1001,7 @@ 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.
@@ -1015,6 +1040,50 @@ 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
@@ -1034,8 +1103,11 @@ 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
@@ -1105,6 +1177,7 @@ 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
@@ -1118,6 +1191,22 @@ 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',
@@ -1157,6 +1246,14 @@ 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/tools/kvm/kvm_stat/kvm_stat.txt b/tools/kvm/kvm_stat/kvm_stat.txt
index 077bcc7..35587c3 100644
--- a/tools/kvm/kvm_stat/kvm_stat.txt
+++ b/tools/kvm/kvm_stat/kvm_stat.txt
@@ -31,6 +31,8 @@ INTERACTIVE COMMANDS
[horizontal]
*f*:: filter by regular expression
+*g*:: filter by guest name
+
*p*:: filter by PID
*q*:: quit
@@ -62,6 +64,10 @@ OPTIONS
--pid=<pid>::
limit statistics to one virtual machine (pid)
+-g<guest>::
+--guest=<guest_name>::
+ limit statistics to one virtual machine (guest name)
+
-f<fields>::
--fields=<fields>::
fields to display (regex)
--
2.8.4
