src/cpu/kvm/perfevent.cc - public/gem5 - Git at Google

 /*
  * Copyright (c) 2012 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
  * not be construed as granting a license to any other intellectual
  * property including but not limited to intellectual property relating
  * to a hardware implementation of the functionality of the software
  * licensed hereunder.  You may use the software subject to the license
  * terms below provided that you ensure that this notice is replicated
  * unmodified and in its entirety in all distributions of the software,
  * modified or unmodified, in source code or in binary form.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met: redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer;
  * redistributions in binary form must reproduce the above copyright
  * notice, this list of conditions and the following disclaimer in the
  * documentation and/or other materials provided with the distribution;
  * neither the name of the copyright holders nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include <fcntl.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
 #include <syscall.h>
 #include <unistd.h>

 #include <cassert>
 #include <cerrno>
 #include <csignal>
 #include <cstring>

 #include "base/logging.hh"
 #include "perfevent.hh"

 PerfKvmCounterConfig::PerfKvmCounterConfig(uint32_t type, uint64_t config)
 {
     memset(&attr, 0, sizeof(attr));

     attr.size = PERF_ATTR_SIZE_VER0;
     attr.type = type;
     attr.config = config;
 }

 PerfKvmCounterConfig::~PerfKvmCounterConfig()
 {
 }


 PerfKvmCounter::PerfKvmCounter(PerfKvmCounterConfig &config, pid_t tid)
     : fd(-1), ringBuffer(NULL), pageSize(-1)
 {
     attach(config, tid, -1);
 }

 PerfKvmCounter::PerfKvmCounter(PerfKvmCounterConfig &config,
                          pid_t tid, const PerfKvmCounter &parent)
     : fd(-1), ringBuffer(NULL), pageSize(-1)
 {
     attach(config, tid, parent);
 }

 PerfKvmCounter::PerfKvmCounter()
     : fd(-1), ringBuffer(NULL), pageSize(-1)
 {
 }

 PerfKvmCounter::~PerfKvmCounter()
 {
     if (attached())
         detach();
 }

 void
 PerfKvmCounter::detach()
 {
     assert(attached());

     if (munmap(ringBuffer, ringNumPages * pageSize) == -1)
         warn("PerfKvmCounter: Failed to unmap ring buffer (%i)\n",
              errno);
     close(fd);

     fd = -1;
     ringBuffer = NULL;
 }

 void
 PerfKvmCounter::start()
 {
     if (ioctl(PERF_EVENT_IOC_ENABLE, PERF_IOC_FLAG_GROUP) == -1)
         panic("KVM: Failed to enable performance counters (%i)\n", errno);
 }

 void
 PerfKvmCounter::stop()
 {
     if (ioctl(PERF_EVENT_IOC_DISABLE, PERF_IOC_FLAG_GROUP) == -1)
         panic("KVM: Failed to disable performance counters (%i)\n", errno);
 }

 void
 PerfKvmCounter::period(uint64_t period)
 {
     if (ioctl(PERF_EVENT_IOC_PERIOD, &period) == -1)
         panic("KVM: Failed to set period of performance counter (%i)\n", errno);
 }

 void
 PerfKvmCounter::refresh(int refresh)
 {
     if (ioctl(PERF_EVENT_IOC_REFRESH, refresh) == -1)
         panic("KVM: Failed to refresh performance counter (%i)\n", errno);
 }

 uint64_t
 PerfKvmCounter::read() const
 {
     uint64_t value;

     read(&value, sizeof(uint64_t));
     return value;
 }

 void
 PerfKvmCounter::enableSignals(pid_t tid, int signal)
 {
     struct f_owner_ex sigowner;

     sigowner.type = F_OWNER_TID;
     sigowner.pid = tid;

     if (fcntl(F_SETOWN_EX, &sigowner) == -1 ||
         fcntl(F_SETSIG, signal) == -1 ||
         fcntl(F_SETFL, O_ASYNC) == -1)
         panic("PerfKvmCounter: Failed to enable signals for counter (%i)\n",
               errno);
 }

 void
 PerfKvmCounter::attach(PerfKvmCounterConfig &config,
                     pid_t tid, int group_fd)
 {
     assert(!attached());

     fd = syscall(__NR_perf_event_open,
                  &config.attr, tid,
                  -1, // CPU (-1 => Any CPU that the task happens to run on)
                  group_fd,
                  0); // Flags
     if (fd == -1)
     {
         if (errno == EACCES)
         {
             panic("PerfKvmCounter::attach recieved error EACCESS\n"
             "  This error may be caused by a too restrictive setting\n"
             "  in the file '/proc/sys/kernel/perf_event_paranoid'\n"
             "  The default value was changed to 2 in kernel 4.6\n"
             "  A value greater than 1 prevents gem5 from making\n"
             "  the syscall to perf_event_open");
         }
         panic("PerfKvmCounter::attach failed (%i)\n", errno);
     }

     mmapPerf(1);
 }

 pid_t
 PerfKvmCounter::sysGettid()
 {
     return syscall(__NR_gettid);
 }

 void
 PerfKvmCounter::mmapPerf(int pages)
 {
     assert(attached());
     assert(ringBuffer == NULL);

     if (pageSize == -1) {
         pageSize = sysconf(_SC_PAGE_SIZE);
         if (pageSize == -1)
             panic("PerfKvmCounter: Failed to determine page size (%i)\n",
                   errno);
     }

     ringNumPages = pages + 1;
     ringBuffer = (struct perf_event_mmap_page *)mmap(
         NULL, ringNumPages * 4096,
         PROT_READ | PROT_WRITE, MAP_SHARED,
         fd, 0);
     if (ringBuffer == MAP_FAILED)
         panic("PerfKvmCounter: MMAP failed (%i)\n",
               errno);
 }

 int
 PerfKvmCounter::fcntl(int cmd, long p1)
 {
     assert(attached());
     return ::fcntl(fd, cmd, p1);
 }

 int
 PerfKvmCounter::ioctl(int request, long p1)
 {
     assert(attached());
     return ::ioctl(fd, request, p1);
 }

 void
 PerfKvmCounter::read(void *buf, size_t size) const
 {
     char *_buf = (char *)buf;
     size_t _size = size;

     assert(attached());

     do {
         ssize_t ret;
         ret = ::read(fd, _buf, _size);
         switch (ret) {
           case -1:
             if (errno != EAGAIN)
                 panic("PerfKvmCounter::read failed (%i)\n", errno);
             break;

           case 0:
             panic("PerfKvmCounter::read unexpected EOF.\n");

           default:
             _size -= ret;
             _buf += ret;
             break;
         }
     } while (_size);
 }
	/*
	* Copyright (c) 2012 ARM Limited
	* All rights reserved
	*
	* The license below extends only to copyright in the software and shall
	* not be construed as granting a license to any other intellectual
	* property including but not limited to intellectual property relating
	* to a hardware implementation of the functionality of the software
	* licensed hereunder. You may use the software subject to the license
	* terms below provided that you ensure that this notice is replicated
	* unmodified and in its entirety in all distributions of the software,
	* modified or unmodified, in source code or in binary form.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met: redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer;
	* redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution;
	* neither the name of the copyright holders nor the names of its
	* contributors may be used to endorse or promote products derived from
	* this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include <fcntl.h>
	#include <sys/ioctl.h>
	#include <sys/mman.h>
	#include <sys/syscall.h>
	#include <sys/types.h>
	#include <syscall.h>
	#include <unistd.h>

	#include <cassert>
	#include <cerrno>
	#include <csignal>
	#include <cstring>

	#include "base/logging.hh"
	#include "perfevent.hh"

	PerfKvmCounterConfig::PerfKvmCounterConfig(uint32_t type, uint64_t config)
	{
	memset(&attr, 0, sizeof(attr));

	attr.size = PERF_ATTR_SIZE_VER0;
	attr.type = type;
	attr.config = config;
	}

	PerfKvmCounterConfig::~PerfKvmCounterConfig()
	{
	}


	PerfKvmCounter::PerfKvmCounter(PerfKvmCounterConfig &config, pid_t tid)
	: fd(-1), ringBuffer(NULL), pageSize(-1)
	{
	attach(config, tid, -1);
	}

	PerfKvmCounter::PerfKvmCounter(PerfKvmCounterConfig &config,
	pid_t tid, const PerfKvmCounter &parent)
	: fd(-1), ringBuffer(NULL), pageSize(-1)
	{
	attach(config, tid, parent);
	}

	PerfKvmCounter::PerfKvmCounter()
	: fd(-1), ringBuffer(NULL), pageSize(-1)
	{
	}

	PerfKvmCounter::~PerfKvmCounter()
	{
	if (attached())
	detach();
	}

	void
	PerfKvmCounter::detach()
	{
	assert(attached());

	if (munmap(ringBuffer, ringNumPages * pageSize) == -1)
	warn("PerfKvmCounter: Failed to unmap ring buffer (%i)\n",
	errno);
	close(fd);

	fd = -1;
	ringBuffer = NULL;
	}

	void
	PerfKvmCounter::start()
	{
	if (ioctl(PERF_EVENT_IOC_ENABLE, PERF_IOC_FLAG_GROUP) == -1)
	panic("KVM: Failed to enable performance counters (%i)\n", errno);
	}

	void
	PerfKvmCounter::stop()
	{
	if (ioctl(PERF_EVENT_IOC_DISABLE, PERF_IOC_FLAG_GROUP) == -1)
	panic("KVM: Failed to disable performance counters (%i)\n", errno);
	}

	void
	PerfKvmCounter::period(uint64_t period)
	{
	if (ioctl(PERF_EVENT_IOC_PERIOD, &period) == -1)
	panic("KVM: Failed to set period of performance counter (%i)\n", errno);
	}

	void
	PerfKvmCounter::refresh(int refresh)
	{
	if (ioctl(PERF_EVENT_IOC_REFRESH, refresh) == -1)
	panic("KVM: Failed to refresh performance counter (%i)\n", errno);
	}

	uint64_t
	PerfKvmCounter::read() const
	{
	uint64_t value;

	read(&value, sizeof(uint64_t));
	return value;
	}

	void
	PerfKvmCounter::enableSignals(pid_t tid, int signal)
	{
	struct f_owner_ex sigowner;

	sigowner.type = F_OWNER_TID;
	sigowner.pid = tid;

	if (fcntl(F_SETOWN_EX, &sigowner) == -1 \|\|
	fcntl(F_SETSIG, signal) == -1 \|\|
	fcntl(F_SETFL, O_ASYNC) == -1)
	panic("PerfKvmCounter: Failed to enable signals for counter (%i)\n",
	errno);
	}

	void
	PerfKvmCounter::attach(PerfKvmCounterConfig &config,
	pid_t tid, int group_fd)
	{
	assert(!attached());

	fd = syscall(__NR_perf_event_open,
	&config.attr, tid,
	-1, // CPU (-1 => Any CPU that the task happens to run on)
	group_fd,
	0); // Flags
	if (fd == -1)
	{
	if (errno == EACCES)
	{
	panic("PerfKvmCounter::attach recieved error EACCESS\n"
	" This error may be caused by a too restrictive setting\n"
	" in the file '/proc/sys/kernel/perf_event_paranoid'\n"
	" The default value was changed to 2 in kernel 4.6\n"
	" A value greater than 1 prevents gem5 from making\n"
	" the syscall to perf_event_open");
	}
	panic("PerfKvmCounter::attach failed (%i)\n", errno);
	}

	mmapPerf(1);
	}

	pid_t
	PerfKvmCounter::sysGettid()
	{
	return syscall(__NR_gettid);
	}

	void
	PerfKvmCounter::mmapPerf(int pages)
	{
	assert(attached());
	assert(ringBuffer == NULL);

	if (pageSize == -1) {
	pageSize = sysconf(_SC_PAGE_SIZE);
	if (pageSize == -1)
	panic("PerfKvmCounter: Failed to determine page size (%i)\n",
	errno);
	}

	ringNumPages = pages + 1;
	ringBuffer = (struct perf_event_mmap_page *)mmap(
	NULL, ringNumPages * 4096,
	PROT_READ \| PROT_WRITE, MAP_SHARED,
	fd, 0);
	if (ringBuffer == MAP_FAILED)
	panic("PerfKvmCounter: MMAP failed (%i)\n",
	errno);
	}

	int
	PerfKvmCounter::fcntl(int cmd, long p1)
	{
	assert(attached());
	return ::fcntl(fd, cmd, p1);
	}

	int
	PerfKvmCounter::ioctl(int request, long p1)
	{
	assert(attached());
	return ::ioctl(fd, request, p1);
	}

	void
	PerfKvmCounter::read(void *buf, size_t size) const
	{
	char _buf = (char )buf;
	size_t _size = size;

	assert(attached());

	do {
	ssize_t ret;
	ret = ::read(fd, _buf, _size);
	switch (ret) {
	case -1:
	if (errno != EAGAIN)
	panic("PerfKvmCounter::read failed (%i)\n", errno);
	break;

	case 0:
	panic("PerfKvmCounter::read unexpected EOF.\n");

	default:
	_size -= ret;
	_buf += ret;
	break;
	}
	} while (_size);
	}