src/cpu/kvm/perfevent.hh - 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.
  *
  * Authors: Andreas Sandberg
  */

 #ifndef __CPU_KVM_PERFEVENT_HH__
 #define __CPU_KVM_PERFEVENT_HH__

 #include <linux/perf_event.h>
 #include <sys/types.h>

 #include <inttypes.h>

 #include "config/have_perf_attr_exclude_host.hh"

 /**
  * PerfEvent counter configuration.
  */
 class PerfKvmCounterConfig
 {
   public:
     /**
      * Initialize PerfEvent counter configuration structure
      *
      * PerfEvent has the concept of counter types, which is a way to
      * abstract hardware performance counters or access software
      * events. The type field in the configuration specifies what type
      * of counter this is. For hardware performance counters, it's
      * typically PERF_TYPE_HARDWARE, PERF_TYPE_HW_CACHE, or
      * PERF_TYPE_RAW.
      *
      * The 'config' field has different meanings depending on the type
      * of counter. Possible values are listed in perf_event.h in the
      * kernel headers. When using raw counters, the value is the raw
      * value written to the performance counter configuration register
      * (some bits dealing with sampling and similar features are
      * usually masked).
      *
      * @param type Counter type.
      * @param config Counter configuration
      */
     PerfKvmCounterConfig(uint32_t type, uint64_t config);
     ~PerfKvmCounterConfig();

     /**
      * Set the initial sample period (overflow count) of an event. If
      * this is set to 0, the event acts as a normal counting event and
      * does not trigger overflows.
      *
      * @param period Number of counter events before the counter
      * overflows
      */
     PerfKvmCounterConfig &samplePeriod(uint64_t period) {
         attr.freq = 0;
         attr.sample_period = period;
         return *this;
     }

     /**
      * Set the number of samples that need to be triggered before
      * reporting data as being available on the perf event
      * FD. Defaults to 0, which disables overflow reporting.
      *
      * @param events Number of overflows before signaling a wake up
      */
     PerfKvmCounterConfig &wakeupEvents(uint32_t events) {
         attr.watermark = 0;
         attr.wakeup_events = events;
         return *this;
     }

     /**
      * Don't start the performance counter automatically when
      * attaching it.
      *
      * @param val true to disable, false to enable the counter
      */
     PerfKvmCounterConfig &disabled(bool val) {
         attr.disabled = val;
         return *this;
     }

     /**
      * Force the group to be on the active all the time (i.e.,
      * disallow multiplexing).
      *
      * Only applies to group leaders.
      *
      * @param val true to pin the counter
      */
     PerfKvmCounterConfig &pinned(bool val) {
         attr.pinned = val;
         return *this;
     }

     /**
      * Exclude the events from the host (i.e., only include events
      * from the guest system).
      *
      * Intel CPUs seem to support this attribute from Linux 3.2 and
      * onwards. Non-x86 architectures currently ignore this attribute
      * (Linux 3.12-rc5).
      *
      * @warn This attribute is ignored if it isn't present in the
      * kernel headers or if the kernel doesn't support it.
      *
      * @param val true to exclude host events
      */
     PerfKvmCounterConfig &exclude_host(bool val) {
 #if HAVE_PERF_ATTR_EXCLUDE_HOST == 1
         attr.exclude_host = val;
 #endif
         return *this;
     }

     /**
      * Exclude the hyper visor (i.e., only include events from the
      * guest system).
      *
      * @warn This is attribute only seems to be ignored on Intel.
      *
      * @param val true to exclude host events
      */
     PerfKvmCounterConfig &exclude_hv(bool val) {
         attr.exclude_hv = val;
         return *this;
     }

     /** Underlying perf_event_attr structure describing the counter */
     struct perf_event_attr attr;
 };

 /**
  * An instance of a performance counter.
  */
 class PerfKvmCounter
 {
 public:
     /**
      * Create and attach a new counter group.
      *
      * @param config Counter configuration
      * @param tid Thread to sample (0 indicates current thread)
      */
     PerfKvmCounter(PerfKvmCounterConfig &config, pid_t tid);
     /**
      * Create and attach a new counter and make it a member of an
      * exist counter group.
      *
      * @param config Counter configuration
      * @param tid Thread to sample (0 indicates current thread)
      * @param parent Group leader
      */
     PerfKvmCounter(PerfKvmCounterConfig &config,
                 pid_t tid, const PerfKvmCounter &parent);
     /**
      * Create a new counter, but don't attach it.
      */
     PerfKvmCounter();
     ~PerfKvmCounter();


     /**
      * Attach a counter.
      *
      * @note This operation is only supported if the counter isn't
      * already attached.
      *
      * @param config Counter configuration
      * @param tid Thread to sample (0 indicates current thread)
      */
     void attach(PerfKvmCounterConfig &config, pid_t tid) {
         attach(config, tid, -1);
     }

     /**
      * Attach a counter and make it a member of an existing counter
      * group.
      *
      * @note This operation is only supported if the counter isn't
      * already attached.
      *
      * @param config Counter configuration
      * @param tid Thread to sample (0 indicates current thread)
      * @param parent Group leader
      */
     void attach(PerfKvmCounterConfig &config,
                 pid_t tid, const PerfKvmCounter &parent) {
         attach(config, tid, parent.fd);
     }

     /** Detach a counter from PerfEvent. */
     void detach();

     /** Check if a counter is attached. */
     bool attached() const { return fd != -1; }

     /**
      * Start counting.
      *
      * @note If this counter is a group leader, it will start the
      * entire group.
      */
     void start();

     /**
      * Stop counting.
      *
      * @note If this counter is a group leader, it will stop the
      * entire group.
      */
     void stop();

     /**
      * Update the period of an overflow counter.
      *
      * @warning This ioctl has some pretty bizarre semantics. It seems
      * like the new period isn't effective until after the next
      * counter overflow. If you use this method to change the sample
      * period, you will see one sample with the old period and then
      * start sampling with the new period. This problem was fixed for
      * ARM in version 3.7 of the kernel.
      *
      * @warning This method doesn't work at all on some 2.6.3x kernels
      * since it has inverted check for the return value when copying
      * parameters from userspace.
      *
      * @param period Overflow period in events
      */
     void period(uint64_t period);

     /**
      * Enable a counter for a fixed number of events.
      *
      * When this method is called, perf event enables the counter if
      * it was disabled. It then leaves the counter enabled until it
      * has overflowed a refresh times.
      *
      * @note This does not update the period of the counter.
      *
      * @param refresh Number of overflows before disabling the
      * counter.
      */
     void refresh(int refresh);

     /**
      * Read the current value of a counter.
      */
     uint64_t read() const;

     /**
      * Enable signal delivery to a thread on counter overflow.
      *
      * @param tid Thread to deliver signal to
      * @param signal Signal to send upon overflow
      */
     void enableSignals(pid_t tid, int signal);

     /**
      * Enable signal delivery on counter overflow. Identical to
      * enableSignals(pid_t) when called with the current TID as its
      * parameter.
      *
      * @param signal Signal to send upon overflow
      */
     void enableSignals(int signal) { enableSignals(sysGettid(), signal); }

 private:
     // Disallow copying
     PerfKvmCounter(const PerfKvmCounter &that);
     // Disallow assignment
     PerfKvmCounter &operator=(const PerfKvmCounter &that);

     void attach(PerfKvmCounterConfig &config, pid_t tid, int group_fd);

     /**
      * Get the TID of the current thread.
      *
      * @return Current thread's TID
      */
     pid_t sysGettid();

     /**
      * MMAP the PerfEvent file descriptor.
      *
      * @note We currently don't use the ring buffer, but PerfEvent
      * requires this to be mapped for overflow handling to work.
      *
      * @note Overflow handling requires at least one buf_page to be
      * mapped.
      *
      * @param pages number of pages in circular sample buffer. Must be
      * an even power of 2.
      */
     void mmapPerf(int pages);

     /** @{ */
     /**
      * PerfEvent fnctl interface.
      *
      * @param cmd fcntl command
      * @param p1 Request parameter
      *
      * @return -1 on error (error number in errno), ioctl dependent
      * value otherwise.
      */
     int fcntl(int cmd, long p1);
     int fcntl(int cmd, void *p1) { return fcntl(cmd, (long)p1); }
     /** @} */

     /** @{ */
     /**
      * PerfEvent ioctl interface.
      *
      * @param request PerfEvent request
      * @param p1 Optional request parameter
      *
      * @return -1 on error (error number in errno), ioctl dependent
      * value otherwise.
      */
     int ioctl(int request, long p1);
     int ioctl(int request, void *p1) { return ioctl(request, (long)p1); }
     int ioctl(int request) { return ioctl(request, 0L); }
     /** @} */

     /**
      * Perform a read from the counter file descriptor.
      *
      * @param buf Destination buffer
      * @param size Amount of data to read
      */
     void read(void *buf, size_t size) const;

     /**
      * PerfEvent file descriptor associated with counter. -1 if not
      * attached to PerfEvent.
      */
     int fd;

     /** Memory mapped PerfEvent sample ring buffer */
     struct perf_event_mmap_page *ringBuffer;
     /** Total number of pages in ring buffer */
     int ringNumPages;

     /** Cached host page size */
     long pageSize;
 };

 #endif
	/*
	* 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
	*/

	#ifndef __CPU_KVM_PERFEVENT_HH__
	#define __CPU_KVM_PERFEVENT_HH__

	#include <linux/perf_event.h>
	#include <sys/types.h>

	#include <inttypes.h>

	#include "config/have_perf_attr_exclude_host.hh"

	/**
	* PerfEvent counter configuration.
	*/
	class PerfKvmCounterConfig
	{
	public:
	/**
	* Initialize PerfEvent counter configuration structure
	*
	* PerfEvent has the concept of counter types, which is a way to
	* abstract hardware performance counters or access software
	* events. The type field in the configuration specifies what type
	* of counter this is. For hardware performance counters, it's
	* typically PERF_TYPE_HARDWARE, PERF_TYPE_HW_CACHE, or
	* PERF_TYPE_RAW.
	*
	* The 'config' field has different meanings depending on the type
	* of counter. Possible values are listed in perf_event.h in the
	* kernel headers. When using raw counters, the value is the raw
	* value written to the performance counter configuration register
	* (some bits dealing with sampling and similar features are
	* usually masked).
	*
	* @param type Counter type.
	* @param config Counter configuration
	*/
	PerfKvmCounterConfig(uint32_t type, uint64_t config);
	~PerfKvmCounterConfig();

	/**
	* Set the initial sample period (overflow count) of an event. If
	* this is set to 0, the event acts as a normal counting event and
	* does not trigger overflows.
	*
	* @param period Number of counter events before the counter
	* overflows
	*/
	PerfKvmCounterConfig &samplePeriod(uint64_t period) {
	attr.freq = 0;
	attr.sample_period = period;
	return *this;
	}

	/**
	* Set the number of samples that need to be triggered before
	* reporting data as being available on the perf event
	* FD. Defaults to 0, which disables overflow reporting.
	*
	* @param events Number of overflows before signaling a wake up
	*/
	PerfKvmCounterConfig &wakeupEvents(uint32_t events) {
	attr.watermark = 0;
	attr.wakeup_events = events;
	return *this;
	}

	/**
	* Don't start the performance counter automatically when
	* attaching it.
	*
	* @param val true to disable, false to enable the counter
	*/
	PerfKvmCounterConfig &disabled(bool val) {
	attr.disabled = val;
	return *this;
	}

	/**
	* Force the group to be on the active all the time (i.e.,
	* disallow multiplexing).
	*
	* Only applies to group leaders.
	*
	* @param val true to pin the counter
	*/
	PerfKvmCounterConfig &pinned(bool val) {
	attr.pinned = val;
	return *this;
	}

	/**
	* Exclude the events from the host (i.e., only include events
	* from the guest system).
	*
	* Intel CPUs seem to support this attribute from Linux 3.2 and
	* onwards. Non-x86 architectures currently ignore this attribute
	* (Linux 3.12-rc5).
	*
	* @warn This attribute is ignored if it isn't present in the
	* kernel headers or if the kernel doesn't support it.
	*
	* @param val true to exclude host events
	*/
	PerfKvmCounterConfig &exclude_host(bool val) {
	#if HAVE_PERF_ATTR_EXCLUDE_HOST == 1
	attr.exclude_host = val;
	#endif
	return *this;
	}

	/**
	* Exclude the hyper visor (i.e., only include events from the
	* guest system).
	*
	* @warn This is attribute only seems to be ignored on Intel.
	*
	* @param val true to exclude host events
	*/
	PerfKvmCounterConfig &exclude_hv(bool val) {
	attr.exclude_hv = val;
	return *this;
	}

	/** Underlying perf_event_attr structure describing the counter */
	struct perf_event_attr attr;
	};

	/**
	* An instance of a performance counter.
	*/
	class PerfKvmCounter
	{
	public:
	/**
	* Create and attach a new counter group.
	*
	* @param config Counter configuration
	* @param tid Thread to sample (0 indicates current thread)
	*/
	PerfKvmCounter(PerfKvmCounterConfig &config, pid_t tid);
	/**
	* Create and attach a new counter and make it a member of an
	* exist counter group.
	*
	* @param config Counter configuration
	* @param tid Thread to sample (0 indicates current thread)
	* @param parent Group leader
	*/
	PerfKvmCounter(PerfKvmCounterConfig &config,
	pid_t tid, const PerfKvmCounter &parent);
	/**
	* Create a new counter, but don't attach it.
	*/
	PerfKvmCounter();
	~PerfKvmCounter();


	/**
	* Attach a counter.
	*
	* @note This operation is only supported if the counter isn't
	* already attached.
	*
	* @param config Counter configuration
	* @param tid Thread to sample (0 indicates current thread)
	*/
	void attach(PerfKvmCounterConfig &config, pid_t tid) {
	attach(config, tid, -1);
	}

	/**
	* Attach a counter and make it a member of an existing counter
	* group.
	*
	* @note This operation is only supported if the counter isn't
	* already attached.
	*
	* @param config Counter configuration
	* @param tid Thread to sample (0 indicates current thread)
	* @param parent Group leader
	*/
	void attach(PerfKvmCounterConfig &config,
	pid_t tid, const PerfKvmCounter &parent) {
	attach(config, tid, parent.fd);
	}

	/** Detach a counter from PerfEvent. */
	void detach();

	/** Check if a counter is attached. */
	bool attached() const { return fd != -1; }

	/**
	* Start counting.
	*
	* @note If this counter is a group leader, it will start the
	* entire group.
	*/
	void start();

	/**
	* Stop counting.
	*
	* @note If this counter is a group leader, it will stop the
	* entire group.
	*/
	void stop();

	/**
	* Update the period of an overflow counter.
	*
	* @warning This ioctl has some pretty bizarre semantics. It seems
	* like the new period isn't effective until after the next
	* counter overflow. If you use this method to change the sample
	* period, you will see one sample with the old period and then
	* start sampling with the new period. This problem was fixed for
	* ARM in version 3.7 of the kernel.
	*
	* @warning This method doesn't work at all on some 2.6.3x kernels
	* since it has inverted check for the return value when copying
	* parameters from userspace.
	*
	* @param period Overflow period in events
	*/
	void period(uint64_t period);

	/**
	* Enable a counter for a fixed number of events.
	*
	* When this method is called, perf event enables the counter if
	* it was disabled. It then leaves the counter enabled until it
	* has overflowed a refresh times.
	*
	* @note This does not update the period of the counter.
	*
	* @param refresh Number of overflows before disabling the
	* counter.
	*/
	void refresh(int refresh);

	/**
	* Read the current value of a counter.
	*/
	uint64_t read() const;

	/**
	* Enable signal delivery to a thread on counter overflow.
	*
	* @param tid Thread to deliver signal to
	* @param signal Signal to send upon overflow
	*/
	void enableSignals(pid_t tid, int signal);

	/**
	* Enable signal delivery on counter overflow. Identical to
	* enableSignals(pid_t) when called with the current TID as its
	* parameter.
	*
	* @param signal Signal to send upon overflow
	*/
	void enableSignals(int signal) { enableSignals(sysGettid(), signal); }

	private:
	// Disallow copying
	PerfKvmCounter(const PerfKvmCounter &that);
	// Disallow assignment
	PerfKvmCounter &operator=(const PerfKvmCounter &that);

	void attach(PerfKvmCounterConfig &config, pid_t tid, int group_fd);

	/**
	* Get the TID of the current thread.
	*
	* @return Current thread's TID
	*/
	pid_t sysGettid();

	/**
	* MMAP the PerfEvent file descriptor.
	*
	* @note We currently don't use the ring buffer, but PerfEvent
	* requires this to be mapped for overflow handling to work.
	*
	* @note Overflow handling requires at least one buf_page to be
	* mapped.
	*
	* @param pages number of pages in circular sample buffer. Must be
	* an even power of 2.
	*/
	void mmapPerf(int pages);

	/** @{ */
	/**
	* PerfEvent fnctl interface.
	*
	* @param cmd fcntl command
	* @param p1 Request parameter
	*
	* @return -1 on error (error number in errno), ioctl dependent
	* value otherwise.
	*/
	int fcntl(int cmd, long p1);
	int fcntl(int cmd, void *p1) { return fcntl(cmd, (long)p1); }
	/** @} */

	/** @{ */
	/**
	* PerfEvent ioctl interface.
	*
	* @param request PerfEvent request
	* @param p1 Optional request parameter
	*
	* @return -1 on error (error number in errno), ioctl dependent
	* value otherwise.
	*/
	int ioctl(int request, long p1);
	int ioctl(int request, void *p1) { return ioctl(request, (long)p1); }
	int ioctl(int request) { return ioctl(request, 0L); }
	/** @} */

	/**
	* Perform a read from the counter file descriptor.
	*
	* @param buf Destination buffer
	* @param size Amount of data to read
	*/
	void read(void *buf, size_t size) const;

	/**
	* PerfEvent file descriptor associated with counter. -1 if not
	* attached to PerfEvent.
	*/
	int fd;

	/** Memory mapped PerfEvent sample ring buffer */
	struct perf_event_mmap_page *ringBuffer;
	/** Total number of pages in ring buffer */
	int ringNumPages;

	/** Cached host page size */
	long pageSize;
	};

	#endif