tests/avocado/acpi-bits/bits-tests/smilatency.py2

   1 # Copyright (c) 2015, Intel Corporation
   2 # All rights reserved.
   3 #
   4 # SPDX-License-Identifier: BSD-3-Clause
   5
   6 # Redistribution and use in source and binary forms, with or without
   7 # modification, are permitted provided that the following conditions are met:
   8 #
   9 #     * Redistributions of source code must retain the above copyright notice,
  10 #       this list of conditions and the following disclaimer.
  11 #     * Redistributions in binary form must reproduce the above copyright notice,
  12 #       this list of conditions and the following disclaimer in the documentation
  13 #       and/or other materials provided with the distribution.
  14 #     * Neither the name of Intel Corporation nor the names of its contributors
  15 #       may be used to endorse or promote products derived from this software
  16 #       without specific prior written permission.
  17 #
  18 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
  19 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  20 # WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  21 # DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
  22 # ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  23 # (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  24 # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  25 # ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  27 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28
  29 # This script runs only from the biosbits VM.
  30
  31 """SMI latency test."""
  32
  33 import bits
  34 from collections import namedtuple
  35 import testsuite
  36 import time
  37 import usb
  38
  39 def register_tests():
  40      pass
  41 #    testsuite.add_test("SMI latency test", smi_latency);
  42 #    testsuite.add_test("SMI latency test with USB disabled via BIOS handoff", test_with_usb_disabled, runall=False);
  43
  44 def smi_latency():
  45     MSR_SMI_COUNT = 0x34
  46
  47     print "Warning: touching the keyboard can affect the results of this test."
  48
  49     tsc_per_sec = bits.tsc_per_sec()
  50     tsc_per_usec = tsc_per_sec / (1000 * 1000)
  51     bins = [long(tsc_per_usec * 10**i) for i in range(9)]
  52     bin_descs = [
  53         "0     < t <=   1us",
  54         "1us   < t <=  10us",
  55         "10us  < t <= 100us",
  56         "100us < t <=   1ms",
  57         "1ms   < t <=  10ms",
  58         "10ms  < t <= 100ms",
  59         "100ms < t <=   1s ",
  60         "1s    < t <=  10s ",
  61         "10s   < t <= 100s ",
  62         "100s  < t         ",
  63     ]
  64
  65     print "Starting test. Wait here, I will be back in 15 seconds."
  66     (max_latency, smi_count_delta, bins) = bits.smi_latency(long(15 * tsc_per_sec), bins)
  67     BinType = namedtuple('BinType', ("max", "total", "count", "times"))
  68     bins = [BinType(*b) for b in bins]
  69
  70     testsuite.test("SMI latency < 150us to minimize risk of OS timeouts", max_latency / tsc_per_usec <= 150)
  71     if not testsuite.show_detail():
  72         return
  73
  74     for bin, desc in zip(bins, bin_descs):
  75         if bin.count == 0:
  76             continue
  77         testsuite.print_detail("{}; average = {}; count = {}".format(desc, bits.format_tsc(bin.total/bin.count), bin.count))
  78         deltas = (bits.format_tsc(t2 - t1) for t1,t2 in zip(bin.times, bin.times[1:]))
  79         testsuite.print_detail(" Times between first few observations: {}".format(" ".join("{:>6}".format(delta) for delta in deltas)))
  80
  81     if smi_count_delta is not None:
  82         testsuite.print_detail("{} SMI detected using MSR_SMI_COUNT (MSR {:#x})".format(smi_count_delta, MSR_SMI_COUNT))
  83
  84     testsuite.print_detail("Summary of impact: observed maximum latency = {}".format(bits.format_tsc(max_latency)))
  85
  86 def test_with_usb_disabled():
  87     if usb.handoff_to_os():
  88         smi_latency()
  89
  90 def average_io_smi(port, value, count):
  91     def f():
  92         tsc_start = bits.rdtsc()
  93         bits.outb(port, value)
  94         return bits.rdtsc() - tsc_start
  95     counts = [f() for i in range(count)]
  96     return sum(counts)/len(counts)
  97
  98 def time_io_smi(port=0xb2, value=0, count=1000):
  99     count_for_estimate = 10
 100     start = time.time()
 101     average_io_smi(port, value, count_for_estimate)
 102     avg10 = time.time() - start
 103     estimate = avg10 * count/count_for_estimate
 104     if estimate > 1:
 105         print "Running test, estimated time: {}s".format(int(estimate))
 106     average = average_io_smi(port, value, count)
 107     print "Average of {} SMIs (via outb, port={:#x}, value={:#x}): {}".format(count, port, value, bits.format_tsc(average))