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/*
* 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.
*
* Authors: Andreas Sandberg
*/
#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);
}