qemu-e2k/include/qemu/timer.h

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#ifndef QEMU_TIMER_H
#define QEMU_TIMER_H
#include "qemu/bitops.h"
#include "qemu/notify.h"
#include "qemu/host-utils.h"
#define NANOSECONDS_PER_SECOND 1000000000LL
/* timers */
#define SCALE_MS 1000000
#define SCALE_US 1000
#define SCALE_NS 1
/**
* QEMUClockType:
*
* The following clock types are available:
*
* @QEMU_CLOCK_REALTIME: Real time clock
*
* The real time clock should be used only for stuff which does not
* change the virtual machine state, as it runs even if the virtual
* machine is stopped.
*
* @QEMU_CLOCK_VIRTUAL: virtual clock
*
* The virtual clock only runs during the emulation. It stops
* when the virtual machine is stopped.
*
* @QEMU_CLOCK_HOST: host clock
*
* The host clock should be used for device models that emulate accurate
* real time sources. It will continue to run when the virtual machine
* is suspended, and it will reflect system time changes the host may
* undergo (e.g. due to NTP).
*
* @QEMU_CLOCK_VIRTUAL_RT: realtime clock used for icount warp
*
* Outside icount mode, this clock is the same as @QEMU_CLOCK_VIRTUAL.
* In icount mode, this clock counts nanoseconds while the virtual
* machine is running. It is used to increase @QEMU_CLOCK_VIRTUAL
* while the CPUs are sleeping and thus not executing instructions.
*/
typedef enum {
QEMU_CLOCK_REALTIME = 0,
QEMU_CLOCK_VIRTUAL = 1,
QEMU_CLOCK_HOST = 2,
QEMU_CLOCK_VIRTUAL_RT = 3,
QEMU_CLOCK_MAX
} QEMUClockType;
/**
* QEMU Timer attributes:
*
* An individual timer may be given one or multiple attributes when initialized.
* Each attribute corresponds to one bit. Attributes modify the processing
* of timers when they fire.
*
* The following attributes are available:
*
* QEMU_TIMER_ATTR_EXTERNAL: drives external subsystem
* QEMU_TIMER_ATTR_ALL: mask for all existing attributes
*
* Timers with this attribute do not recorded in rr mode, therefore it could be
* used for the subsystems that operate outside the guest core. Applicable only
* with virtual clock type.
*/
#define QEMU_TIMER_ATTR_EXTERNAL ((int)BIT(0))
#define QEMU_TIMER_ATTR_ALL 0xffffffff
typedef struct QEMUTimerList QEMUTimerList;
struct QEMUTimerListGroup {
QEMUTimerList *tl[QEMU_CLOCK_MAX];
};
typedef void QEMUTimerCB(void *opaque);
typedef void QEMUTimerListNotifyCB(void *opaque, QEMUClockType type);
struct QEMUTimer {
int64_t expire_time; /* in nanoseconds */
QEMUTimerList *timer_list;
QEMUTimerCB *cb;
void *opaque;
QEMUTimer *next;
int attributes;
int scale;
};
extern QEMUTimerListGroup main_loop_tlg;
/*
* qemu_clock_get_ns;
* @type: the clock type
*
* Get the nanosecond value of a clock with
* type @type
*
* Returns: the clock value in nanoseconds
*/
int64_t qemu_clock_get_ns(QEMUClockType type);
/**
* qemu_clock_get_ms;
* @type: the clock type
*
* Get the millisecond value of a clock with
* type @type
*
* Returns: the clock value in milliseconds
*/
static inline int64_t qemu_clock_get_ms(QEMUClockType type)
{
return qemu_clock_get_ns(type) / SCALE_MS;
}
/**
* qemu_clock_get_us;
* @type: the clock type
*
* Get the microsecond value of a clock with
* type @type
*
* Returns: the clock value in microseconds
*/
static inline int64_t qemu_clock_get_us(QEMUClockType type)
{
return qemu_clock_get_ns(type) / SCALE_US;
}
/**
* qemu_clock_has_timers:
* @type: the clock type
*
* Determines whether a clock's default timer list
* has timers attached
*
* Note that this function should not be used when other threads also access
* the timer list. The return value may be outdated by the time it is acted
* upon.
*
* Returns: true if the clock's default timer list
* has timers attached
*/
bool qemu_clock_has_timers(QEMUClockType type);
/**
* qemu_clock_expired:
* @type: the clock type
*
* Determines whether a clock's default timer list
* has an expired timer.
*
* Returns: true if the clock's default timer list has
* an expired timer
*/
bool qemu_clock_expired(QEMUClockType type);
/**
* qemu_clock_use_for_deadline:
* @type: the clock type
*
* Determine whether a clock should be used for deadline
* calculations. Some clocks, for instance vm_clock with
* use_icount set, do not count in nanoseconds. Such clocks
* are not used for deadline calculations, and are presumed
* to interrupt any poll using qemu_notify/aio_notify
* etc.
*
* Returns: true if the clock runs in nanoseconds and
* should be used for a deadline.
*/
bool qemu_clock_use_for_deadline(QEMUClockType type);
/**
* qemu_clock_deadline_ns_all:
* @type: the clock type
* @attr_mask: mask for the timer attributes that are included
* in deadline calculation
*
* Calculate the deadline across all timer lists associated
* with a clock (as opposed to just the default one)
* in nanoseconds, or -1 if no timer is set to expire.
*
* Returns: time until expiry in nanoseconds or -1
*/
int64_t qemu_clock_deadline_ns_all(QEMUClockType type, int attr_mask);
/**
* qemu_clock_get_main_loop_timerlist:
* @type: the clock type
*
* Return the default timer list associated with a clock.
*
* Returns: the default timer list
*/
QEMUTimerList *qemu_clock_get_main_loop_timerlist(QEMUClockType type);
/**
* qemu_clock_nofify:
* @type: the clock type
*
* Call the notifier callback connected with the default timer
* list linked to the clock, or qemu_notify() if none.
*/
void qemu_clock_notify(QEMUClockType type);
/**
* qemu_clock_enable:
* @type: the clock type
* @enabled: true to enable, false to disable
*
* Enable or disable a clock
* Disabling the clock will wait for related timerlists to stop
* executing qemu_run_timers. Thus, this functions should not
* be used from the callback of a timer that is based on @clock.
* Doing so would cause a deadlock.
*
* Caller should hold BQL.
*/
void qemu_clock_enable(QEMUClockType type, bool enabled);
/**
* qemu_start_warp_timer:
*
* Starts a timer for virtual clock update
*/
void qemu_start_warp_timer(void);
/**
* qemu_clock_run_timers:
* @type: clock on which to operate
*
* Run all the timers associated with the default timer list
* of a clock.
*
* Returns: true if any timer ran.
*/
bool qemu_clock_run_timers(QEMUClockType type);
/**
* qemu_clock_run_all_timers:
*
* Run all the timers associated with the default timer list
* of every clock.
*
* Returns: true if any timer ran.
*/
bool qemu_clock_run_all_timers(void);
/*
* QEMUTimerList
*/
/**
* timerlist_new:
* @type: the clock type to associate with the timerlist
* @cb: the callback to call on notification
* @opaque: the opaque pointer to pass to the callback
*
* Create a new timerlist associated with the clock of
* type @type.
*
* Returns: a pointer to the QEMUTimerList created
*/
QEMUTimerList *timerlist_new(QEMUClockType type,
QEMUTimerListNotifyCB *cb, void *opaque);
/**
* timerlist_free:
* @timer_list: the timer list to free
*
* Frees a timer_list. It must have no active timers.
*/
void timerlist_free(QEMUTimerList *timer_list);
/**
* timerlist_has_timers:
* @timer_list: the timer list to operate on
*
* Determine whether a timer list has active timers
*
* Note that this function should not be used when other threads also access
* the timer list. The return value may be outdated by the time it is acted
* upon.
*
* Returns: true if the timer list has timers.
*/
bool timerlist_has_timers(QEMUTimerList *timer_list);
/**
* timerlist_expired:
* @timer_list: the timer list to operate on
*
* Determine whether a timer list has any timers which
* are expired.
*
* Returns: true if the timer list has timers which
* have expired.
*/
bool timerlist_expired(QEMUTimerList *timer_list);
/**
* timerlist_deadline_ns:
* @timer_list: the timer list to operate on
*
* Determine the deadline for a timer_list, i.e.
* the number of nanoseconds until the first timer
* expires. Return -1 if there are no timers.
*
* Returns: the number of nanoseconds until the earliest
* timer expires -1 if none
*/
int64_t timerlist_deadline_ns(QEMUTimerList *timer_list);
/**
* timerlist_get_clock:
* @timer_list: the timer list to operate on
*
* Determine the clock type associated with a timer list.
*
* Returns: the clock type associated with the
* timer list.
*/
QEMUClockType timerlist_get_clock(QEMUTimerList *timer_list);
/**
* timerlist_run_timers:
* @timer_list: the timer list to use
*
* Call all expired timers associated with the timer list.
*
* Returns: true if any timer expired
*/
bool timerlist_run_timers(QEMUTimerList *timer_list);
/**
* timerlist_notify:
* @timer_list: the timer list to use
*
* call the notifier callback associated with the timer list.
*/
void timerlist_notify(QEMUTimerList *timer_list);
/*
* QEMUTimerListGroup
*/
/**
* timerlistgroup_init:
* @tlg: the timer list group
* @cb: the callback to call when a notify is required
* @opaque: the opaque pointer to be passed to the callback.
*
* Initialise a timer list group. This must already be
* allocated in memory and zeroed. The notifier callback is
* called whenever a clock in the timer list group is
* reenabled or whenever a timer associated with any timer
* list is modified. If @cb is specified as null, qemu_notify()
* is used instead.
*/
void timerlistgroup_init(QEMUTimerListGroup *tlg,
QEMUTimerListNotifyCB *cb, void *opaque);
/**
* timerlistgroup_deinit:
* @tlg: the timer list group
*
* Deinitialise a timer list group. This must already be
* initialised. Note the memory is not freed.
*/
void timerlistgroup_deinit(QEMUTimerListGroup *tlg);
/**
* timerlistgroup_run_timers:
* @tlg: the timer list group
*
* Run the timers associated with a timer list group.
* This will run timers on multiple clocks.
*
* Returns: true if any timer callback ran
*/
bool timerlistgroup_run_timers(QEMUTimerListGroup *tlg);
/**
* timerlistgroup_deadline_ns:
* @tlg: the timer list group
*
* Determine the deadline of the soonest timer to
* expire associated with any timer list linked to
* the timer list group. Only clocks suitable for
* deadline calculation are included.
*
* Returns: the deadline in nanoseconds or -1 if no
* timers are to expire.
*/
int64_t timerlistgroup_deadline_ns(QEMUTimerListGroup *tlg);
/*
* QEMUTimer
*/
/**
* timer_init_full:
* @ts: the timer to be initialised
* @timer_list_group: (optional) the timer list group to attach the timer to
* @type: the clock type to use
* @scale: the scale value for the timer
* @attributes: 0, or one or more OR'ed QEMU_TIMER_ATTR_<id> values
* @cb: the callback to be called when the timer expires
* @opaque: the opaque pointer to be passed to the callback
*
* Initialise a timer with the given scale and attributes,
* and associate it with timer list for given clock @type in @timer_list_group
* (or default timer list group, if NULL).
* The caller is responsible for allocating the memory.
*
* You need not call an explicit deinit call. Simply make
* sure it is not on a list with timer_del.
*/
void timer_init_full(QEMUTimer *ts,
QEMUTimerListGroup *timer_list_group, QEMUClockType type,
int scale, int attributes,
QEMUTimerCB *cb, void *opaque);
/**
* timer_init:
* @ts: the timer to be initialised
* @type: the clock to associate with the timer
* @scale: the scale value for the timer
* @cb: the callback to call when the timer expires
* @opaque: the opaque pointer to pass to the callback
*
* Initialize a timer with the given scale on the default timer list
* associated with the clock.
* See timer_init_full for details.
*/
static inline void timer_init(QEMUTimer *ts, QEMUClockType type, int scale,
QEMUTimerCB *cb, void *opaque)
{
timer_init_full(ts, NULL, type, scale, 0, cb, opaque);
}
/**
* timer_init_ns:
* @ts: the timer to be initialised
* @type: the clock to associate with the timer
* @cb: the callback to call when the timer expires
* @opaque: the opaque pointer to pass to the callback
*
* Initialize a timer with nanosecond scale on the default timer list
* associated with the clock.
* See timer_init_full for details.
*/
static inline void timer_init_ns(QEMUTimer *ts, QEMUClockType type,
QEMUTimerCB *cb, void *opaque)
{
timer_init(ts, type, SCALE_NS, cb, opaque);
}
/**
* timer_init_us:
* @ts: the timer to be initialised
* @type: the clock to associate with the timer
* @cb: the callback to call when the timer expires
* @opaque: the opaque pointer to pass to the callback
*
* Initialize a timer with microsecond scale on the default timer list
* associated with the clock.
* See timer_init_full for details.
*/
static inline void timer_init_us(QEMUTimer *ts, QEMUClockType type,
QEMUTimerCB *cb, void *opaque)
{
timer_init(ts, type, SCALE_US, cb, opaque);
}
/**
* timer_init_ms:
* @ts: the timer to be initialised
* @type: the clock to associate with the timer
* @cb: the callback to call when the timer expires
* @opaque: the opaque pointer to pass to the callback
*
* Initialize a timer with millisecond scale on the default timer list
* associated with the clock.
* See timer_init_full for details.
*/
static inline void timer_init_ms(QEMUTimer *ts, QEMUClockType type,
QEMUTimerCB *cb, void *opaque)
{
timer_init(ts, type, SCALE_MS, cb, opaque);
}
/**
* timer_new_full:
* @timer_list_group: (optional) the timer list group to attach the timer to
* @type: the clock type to use
* @scale: the scale value for the timer
* @attributes: 0, or one or more OR'ed QEMU_TIMER_ATTR_<id> values
* @cb: the callback to be called when the timer expires
* @opaque: the opaque pointer to be passed to the callback
*
* Create a new timer with the given scale and attributes,
* and associate it with timer list for given clock @type in @timer_list_group
* (or default timer list group, if NULL).
* The memory is allocated by the function.
*
* This is not the preferred interface unless you know you
* are going to call timer_free. Use timer_init or timer_init_full instead.
*
* The default timer list has one special feature: in icount mode,
* %QEMU_CLOCK_VIRTUAL timers are run in the vCPU thread. This is
* not true of other timer lists, which are typically associated
* with an AioContext---each of them runs its timer callbacks in its own
* AioContext thread.
*
* Returns: a pointer to the timer
*/
static inline QEMUTimer *timer_new_full(QEMUTimerListGroup *timer_list_group,
QEMUClockType type,
int scale, int attributes,
QEMUTimerCB *cb, void *opaque)
{
QEMUTimer *ts = g_malloc0(sizeof(QEMUTimer));
timer_init_full(ts, timer_list_group, type, scale, attributes, cb, opaque);
return ts;
}
/**
* timer_new:
* @type: the clock type to use
* @scale: the scale value for the timer
* @cb: the callback to be called when the timer expires
* @opaque: the opaque pointer to be passed to the callback
*
* Create a new timer with the given scale,
* and associate it with the default timer list for the clock type @type.
* See timer_new_full for details.
icount: process QEMU_CLOCK_VIRTUAL timers in vCPU thread icount has become much slower after tcg_cpu_exec has stopped using the BQL. There is also a latent bug that is masked by the slowness. The slowness happens because every occurrence of a QEMU_CLOCK_VIRTUAL timer now has to wake up the I/O thread and wait for it. The rendez-vous is mediated by the BQL QemuMutex: - handle_icount_deadline wakes up the I/O thread with BQL taken - the I/O thread wakes up and waits on the BQL - the VCPU thread releases the BQL a little later - the I/O thread raises an interrupt, which calls qemu_cpu_kick - the VCPU thread notices the interrupt, takes the BQL to process it and waits on it All this back and forth is extremely expensive, causing a 6 to 8-fold slowdown when icount is turned on. One may think that the issue is that the VCPU thread is too dependent on the BQL, but then the latent bug comes in. I first tried removing the BQL completely from the x86 cpu_exec, only to see everything break. The only way to fix it (and make everything slow again) was to add a dummy BQL lock/unlock pair. This is because in -icount mode you really have to process the events before the CPU restarts executing the next instruction. Therefore, this series moves the processing of QEMU_CLOCK_VIRTUAL timers straight in the vCPU thread when running in icount mode. The required changes include: - make the timer notification callback wake up TCG's single vCPU thread when run from another thread. By using async_run_on_cpu, the callback can override all_cpu_threads_idle() when the CPU is halted. - move handle_icount_deadline after qemu_tcg_wait_io_event, so that the timer notification callback is invoked after the dummy work item wakes up the vCPU thread - make handle_icount_deadline run the timers instead of just waking the I/O thread. - stop processing the timers in the main loop Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-02 19:56:40 +01:00
*
* Returns: a pointer to the timer
*/
static inline QEMUTimer *timer_new(QEMUClockType type, int scale,
QEMUTimerCB *cb, void *opaque)
{
return timer_new_full(NULL, type, scale, 0, cb, opaque);
}
/**
* timer_new_ns:
* @type: the clock type to associate with the timer
* @cb: the callback to call when the timer expires
* @opaque: the opaque pointer to pass to the callback
*
* Create a new timer with nanosecond scale on the default timer list
* associated with the clock.
* See timer_new_full for details.
icount: process QEMU_CLOCK_VIRTUAL timers in vCPU thread icount has become much slower after tcg_cpu_exec has stopped using the BQL. There is also a latent bug that is masked by the slowness. The slowness happens because every occurrence of a QEMU_CLOCK_VIRTUAL timer now has to wake up the I/O thread and wait for it. The rendez-vous is mediated by the BQL QemuMutex: - handle_icount_deadline wakes up the I/O thread with BQL taken - the I/O thread wakes up and waits on the BQL - the VCPU thread releases the BQL a little later - the I/O thread raises an interrupt, which calls qemu_cpu_kick - the VCPU thread notices the interrupt, takes the BQL to process it and waits on it All this back and forth is extremely expensive, causing a 6 to 8-fold slowdown when icount is turned on. One may think that the issue is that the VCPU thread is too dependent on the BQL, but then the latent bug comes in. I first tried removing the BQL completely from the x86 cpu_exec, only to see everything break. The only way to fix it (and make everything slow again) was to add a dummy BQL lock/unlock pair. This is because in -icount mode you really have to process the events before the CPU restarts executing the next instruction. Therefore, this series moves the processing of QEMU_CLOCK_VIRTUAL timers straight in the vCPU thread when running in icount mode. The required changes include: - make the timer notification callback wake up TCG's single vCPU thread when run from another thread. By using async_run_on_cpu, the callback can override all_cpu_threads_idle() when the CPU is halted. - move handle_icount_deadline after qemu_tcg_wait_io_event, so that the timer notification callback is invoked after the dummy work item wakes up the vCPU thread - make handle_icount_deadline run the timers instead of just waking the I/O thread. - stop processing the timers in the main loop Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-02 19:56:40 +01:00
*
* Returns: a pointer to the newly created timer
*/
static inline QEMUTimer *timer_new_ns(QEMUClockType type, QEMUTimerCB *cb,
void *opaque)
{
return timer_new(type, SCALE_NS, cb, opaque);
}
/**
* timer_new_us:
* @type: the clock type to associate with the timer
* @cb: the callback to call when the timer expires
* @opaque: the opaque pointer to pass to the callback
*
* Create a new timer with microsecond scale on the default timer list
* associated with the clock.
* See timer_new_full for details.
*
* Returns: a pointer to the newly created timer
*/
static inline QEMUTimer *timer_new_us(QEMUClockType type, QEMUTimerCB *cb,
void *opaque)
{
return timer_new(type, SCALE_US, cb, opaque);
}
/**
* timer_new_ms:
* @type: the clock type to associate with the timer
* @cb: the callback to call when the timer expires
* @opaque: the opaque pointer to pass to the callback
*
* Create a new timer with millisecond scale on the default timer list
* associated with the clock.
* See timer_new_full for details.
*
* Returns: a pointer to the newly created timer
*/
static inline QEMUTimer *timer_new_ms(QEMUClockType type, QEMUTimerCB *cb,
void *opaque)
{
return timer_new(type, SCALE_MS, cb, opaque);
}
/**
* timer_deinit:
* @ts: the timer to be de-initialised
*
* Deassociate the timer from any timerlist. You should
* call timer_del before. After this call, any further
* timer_del call cannot cause dangling pointer accesses
* even if the previously used timerlist is freed.
*/
void timer_deinit(QEMUTimer *ts);
/**
* timer_free:
* @ts: the timer
*
* Free a timer (it must not be on the active list)
*/
static inline void timer_free(QEMUTimer *ts)
{
g_free(ts);
}
/**
* timer_del:
* @ts: the timer
*
* Delete a timer from the active list.
*
* This function is thread-safe but the timer and its timer list must not be
* freed while this function is running.
*/
void timer_del(QEMUTimer *ts);
/**
* timer_mod_ns:
* @ts: the timer
* @expire_time: the expiry time in nanoseconds
*
* Modify a timer to expire at @expire_time
*
* This function is thread-safe but the timer and its timer list must not be
* freed while this function is running.
*/
void timer_mod_ns(QEMUTimer *ts, int64_t expire_time);
/**
* timer_mod_anticipate_ns:
* @ts: the timer
* @expire_time: the expiry time in nanoseconds
*
* Modify a timer to expire at @expire_time or the current time,
* whichever comes earlier.
*
* This function is thread-safe but the timer and its timer list must not be
* freed while this function is running.
*/
void timer_mod_anticipate_ns(QEMUTimer *ts, int64_t expire_time);
/**
* timer_mod:
* @ts: the timer
* @expire_time: the expire time in the units associated with the timer
*
* Modify a timer to expiry at @expire_time, taking into
* account the scale associated with the timer.
*
* This function is thread-safe but the timer and its timer list must not be
* freed while this function is running.
*/
void timer_mod(QEMUTimer *ts, int64_t expire_timer);
/**
* timer_mod_anticipate:
* @ts: the timer
* @expire_time: the expiry time in nanoseconds
*
* Modify a timer to expire at @expire_time or the current time, whichever
* comes earlier, taking into account the scale associated with the timer.
*
* This function is thread-safe but the timer and its timer list must not be
* freed while this function is running.
*/
void timer_mod_anticipate(QEMUTimer *ts, int64_t expire_time);
/**
* timer_pending:
* @ts: the timer
*
* Determines whether a timer is pending (i.e. is on the
* active list of timers, whether or not it has not yet expired).
*
* Returns: true if the timer is pending
*/
bool timer_pending(QEMUTimer *ts);
/**
* timer_expired:
* @ts: the timer
* @current_time: the current time
*
* Determines whether a timer has expired.
*
* Returns: true if the timer has expired
*/
bool timer_expired(QEMUTimer *timer_head, int64_t current_time);
/**
* timer_expire_time_ns:
* @ts: the timer
*
* Determine the expiry time of a timer
*
* Returns: the expiry time in nanoseconds
*/
uint64_t timer_expire_time_ns(QEMUTimer *ts);
/**
* timer_get:
* @f: the file
* @ts: the timer
*
* Read a timer @ts from a file @f
*/
void timer_get(QEMUFile *f, QEMUTimer *ts);
/**
* timer_put:
* @f: the file
* @ts: the timer
*/
void timer_put(QEMUFile *f, QEMUTimer *ts);
/*
* General utility functions
*/
/**
* qemu_timeout_ns_to_ms:
* @ns: nanosecond timeout value
*
* Convert a nanosecond timeout value (or -1) to
* a millisecond value (or -1), always rounding up.
*
* Returns: millisecond timeout value
*/
int qemu_timeout_ns_to_ms(int64_t ns);
/**
* qemu_poll_ns:
* @fds: Array of file descriptors
* @nfds: number of file descriptors
* @timeout: timeout in nanoseconds
*
* Perform a poll like g_poll but with a timeout in nanoseconds.
* See g_poll documentation for further details.
*
* Returns: number of fds ready
*/
int qemu_poll_ns(GPollFD *fds, guint nfds, int64_t timeout);
/**
* qemu_soonest_timeout:
* @timeout1: first timeout in nanoseconds (or -1 for infinite)
* @timeout2: second timeout in nanoseconds (or -1 for infinite)
*
* Calculates the soonest of two timeout values. -1 means infinite, which
* is later than any other value.
*
* Returns: soonest timeout value in nanoseconds (or -1 for infinite)
*/
static inline int64_t qemu_soonest_timeout(int64_t timeout1, int64_t timeout2)
{
/* we can abuse the fact that -1 (which means infinite) is a maximal
* value when cast to unsigned. As this is disgusting, it's kept in
* one inline function.
*/
return ((uint64_t) timeout1 < (uint64_t) timeout2) ? timeout1 : timeout2;
}
/**
* initclocks:
*
* Initialise the clock & timer infrastructure
*/
void init_clocks(QEMUTimerListNotifyCB *notify_cb);
int64_t cpu_get_ticks(void);
/* Caller must hold BQL */
void cpu_enable_ticks(void);
/* Caller must hold BQL */
void cpu_disable_ticks(void);
static inline int64_t get_max_clock_jump(void)
{
/* This should be small enough to prevent excessive interrupts from being
* generated by the RTC on clock jumps, but large enough to avoid frequent
* unnecessary resets in idle VMs.
*/
return 60 * NANOSECONDS_PER_SECOND;
}
/*
* Low level clock functions
*/
/* get host real time in nanosecond */
static inline int64_t get_clock_realtime(void)
{
struct timeval tv;
gettimeofday(&tv, NULL);
return tv.tv_sec * 1000000000LL + (tv.tv_usec * 1000);
}
/* Warning: don't insert tracepoints into these functions, they are
also used by simpletrace backend and tracepoints would cause
an infinite recursion! */
#ifdef _WIN32
extern int64_t clock_freq;
static inline int64_t get_clock(void)
{
LARGE_INTEGER ti;
QueryPerformanceCounter(&ti);
return muldiv64(ti.QuadPart, NANOSECONDS_PER_SECOND, clock_freq);
}
#else
extern int use_rt_clock;
static inline int64_t get_clock(void)
{
if (use_rt_clock) {
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
return ts.tv_sec * 1000000000LL + ts.tv_nsec;
} else {
/* XXX: using gettimeofday leads to problems if the date
changes, so it should be avoided. */
return get_clock_realtime();
}
}
#endif
/* icount */
int64_t cpu_get_icount_raw(void);
int64_t cpu_get_icount(void);
int64_t cpu_get_clock(void);
int64_t cpu_icount_to_ns(int64_t icount);
void cpu_update_icount(CPUState *cpu);
/*******************************************/
/* host CPU ticks (if available) */
#if defined(_ARCH_PPC)
static inline int64_t cpu_get_host_ticks(void)
{
int64_t retval;
#ifdef _ARCH_PPC64
/* This reads timebase in one 64bit go and includes Cell workaround from:
http://ozlabs.org/pipermail/linuxppc-dev/2006-October/027052.html
*/
__asm__ __volatile__ ("mftb %0\n\t"
"cmpwi %0,0\n\t"
"beq- $-8"
: "=r" (retval));
#else
/* http://ozlabs.org/pipermail/linuxppc-dev/1999-October/003889.html */
unsigned long junk;
__asm__ __volatile__ ("mfspr %1,269\n\t" /* mftbu */
"mfspr %L0,268\n\t" /* mftb */
"mfspr %0,269\n\t" /* mftbu */
"cmpw %0,%1\n\t"
"bne $-16"
: "=r" (retval), "=r" (junk));
#endif
return retval;
}
#elif defined(__i386__)
static inline int64_t cpu_get_host_ticks(void)
{
int64_t val;
asm volatile ("rdtsc" : "=A" (val));
return val;
}
#elif defined(__x86_64__)
static inline int64_t cpu_get_host_ticks(void)
{
uint32_t low,high;
int64_t val;
asm volatile("rdtsc" : "=a" (low), "=d" (high));
val = high;
val <<= 32;
val |= low;
return val;
}
#elif defined(__hppa__)
static inline int64_t cpu_get_host_ticks(void)
{
int val;
asm volatile ("mfctl %%cr16, %0" : "=r"(val));
return val;
}
#elif defined(__s390__)
static inline int64_t cpu_get_host_ticks(void)
{
int64_t val;
asm volatile("stck 0(%1)" : "=m" (val) : "a" (&val) : "cc");
return val;
}
#elif defined(__sparc__)
static inline int64_t cpu_get_host_ticks (void)
{
#if defined(_LP64)
uint64_t rval;
asm volatile("rd %%tick,%0" : "=r"(rval));
return rval;
#else
/* We need an %o or %g register for this. For recent enough gcc
there is an "h" constraint for that. Don't bother with that. */
union {
uint64_t i64;
struct {
uint32_t high;
uint32_t low;
} i32;
} rval;
asm volatile("rd %%tick,%%g1; srlx %%g1,32,%0; mov %%g1,%1"
: "=r"(rval.i32.high), "=r"(rval.i32.low) : : "g1");
return rval.i64;
#endif
}
#elif defined(__mips__) && \
((defined(__mips_isa_rev) && __mips_isa_rev >= 2) || defined(__linux__))
/*
* binutils wants to use rdhwr only on mips32r2
* but as linux kernel emulate it, it's fine
* to use it.
*
*/
#define MIPS_RDHWR(rd, value) { \
__asm__ __volatile__ (".set push\n\t" \
".set mips32r2\n\t" \
"rdhwr %0, "rd"\n\t" \
".set pop" \
: "=r" (value)); \
}
static inline int64_t cpu_get_host_ticks(void)
{
/* On kernels >= 2.6.25 rdhwr <reg>, $2 and $3 are emulated */
uint32_t count;
static uint32_t cyc_per_count = 0;
if (!cyc_per_count) {
MIPS_RDHWR("$3", cyc_per_count);
}
MIPS_RDHWR("$2", count);
return (int64_t)(count * cyc_per_count);
}
#elif defined(__alpha__)
static inline int64_t cpu_get_host_ticks(void)
{
uint64_t cc;
uint32_t cur, ofs;
asm volatile("rpcc %0" : "=r"(cc));
cur = cc;
ofs = cc >> 32;
return cur - ofs;
}
#else
/* The host CPU doesn't have an easily accessible cycle counter.
Just return a monotonically increasing value. This will be
totally wrong, but hopefully better than nothing. */
static inline int64_t cpu_get_host_ticks(void)
{
return get_clock();
}
#endif
#ifdef CONFIG_PROFILER
static inline int64_t profile_getclock(void)
{
return get_clock();
}
extern int64_t dev_time;
#endif
#endif