accel/tcg: Make icount.o a target agnostic unit

Remove the unused "exec/exec-all.h" header. There is
no more target specific code in it: make it target
agnostic (rename using the '-common' suffix). Since
it is TCG specific, move it to accel/tcg, updating
MAINTAINERS.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Anton Johansson <anjo@rev.ng>
Message-Id: <20230914185718.76241-11-philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

2 files changed, 0 insertions, 507 deletions

diff --git a/softmmu/icount.c b/softmmu/icount.c
deleted file mode 100644
index 4527bfbd6e..0000000000
--- a/softmmu/icount.c
+++ /dev/null
@@ -1,503 +0,0 @@
-/*
- * QEMU System Emulator
- *
- * Copyright (c) 2003-2008 Fabrice Bellard
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-#include "qemu/osdep.h"
-#include "qemu/cutils.h"
-#include "migration/vmstate.h"
-#include "qapi/error.h"
-#include "qemu/error-report.h"
-#include "exec/exec-all.h"
-#include "sysemu/cpus.h"
-#include "sysemu/qtest.h"
-#include "qemu/main-loop.h"
-#include "qemu/option.h"
-#include "qemu/seqlock.h"
-#include "sysemu/replay.h"
-#include "sysemu/runstate.h"
-#include "hw/core/cpu.h"
-#include "sysemu/cpu-timers.h"
-#include "sysemu/cpu-throttle.h"
-#include "timers-state.h"
-
-/*
- * ICOUNT: Instruction Counter
- *
- * this module is split off from cpu-timers because the icount part
- * is TCG-specific, and does not need to be built for other accels.
- */
-static bool icount_sleep = true;
-/* Arbitrarily pick 1MIPS as the minimum allowable speed.  */
-#define MAX_ICOUNT_SHIFT 10
-
-/*
- * 0 = Do not count executed instructions.
- * 1 = Fixed conversion of insn to ns via "shift" option
- * 2 = Runtime adaptive algorithm to compute shift
- */
-int use_icount;
-
-static void icount_enable_precise(void)
-{
-    use_icount = 1;
-}
-
-static void icount_enable_adaptive(void)
-{
-    use_icount = 2;
-}
-
-/*
- * The current number of executed instructions is based on what we
- * originally budgeted minus the current state of the decrementing
- * icount counters in extra/u16.low.
- */
-static int64_t icount_get_executed(CPUState *cpu)
-{
-    return (cpu->icount_budget -
-            (cpu->neg.icount_decr.u16.low + cpu->icount_extra));
-}
-
-/*
- * Update the global shared timer_state.qemu_icount to take into
- * account executed instructions. This is done by the TCG vCPU
- * thread so the main-loop can see time has moved forward.
- */
-static void icount_update_locked(CPUState *cpu)
-{
-    int64_t executed = icount_get_executed(cpu);
-    cpu->icount_budget -= executed;
-
-    qatomic_set_i64(&timers_state.qemu_icount,
-                    timers_state.qemu_icount + executed);
-}
-
-/*
- * Update the global shared timer_state.qemu_icount to take into
- * account executed instructions. This is done by the TCG vCPU
- * thread so the main-loop can see time has moved forward.
- */
-void icount_update(CPUState *cpu)
-{
-    seqlock_write_lock(&timers_state.vm_clock_seqlock,
-                       &timers_state.vm_clock_lock);
-    icount_update_locked(cpu);
-    seqlock_write_unlock(&timers_state.vm_clock_seqlock,
-                         &timers_state.vm_clock_lock);
-}
-
-static int64_t icount_get_raw_locked(void)
-{
-    CPUState *cpu = current_cpu;
-
-    if (cpu && cpu->running) {
-        if (!cpu->neg.can_do_io) {
-            error_report("Bad icount read");
-            exit(1);
-        }
-        /* Take into account what has run */
-        icount_update_locked(cpu);
-    }
-    /* The read is protected by the seqlock, but needs atomic64 to avoid UB */
-    return qatomic_read_i64(&timers_state.qemu_icount);
-}
-
-static int64_t icount_get_locked(void)
-{
-    int64_t icount = icount_get_raw_locked();
-    return qatomic_read_i64(&timers_state.qemu_icount_bias) +
-        icount_to_ns(icount);
-}
-
-int64_t icount_get_raw(void)
-{
-    int64_t icount;
-    unsigned start;
-
-    do {
-        start = seqlock_read_begin(&timers_state.vm_clock_seqlock);
-        icount = icount_get_raw_locked();
-    } while (seqlock_read_retry(&timers_state.vm_clock_seqlock, start));
-
-    return icount;
-}
-
-/* Return the virtual CPU time, based on the instruction counter.  */
-int64_t icount_get(void)
-{
-    int64_t icount;
-    unsigned start;
-
-    do {
-        start = seqlock_read_begin(&timers_state.vm_clock_seqlock);
-        icount = icount_get_locked();
-    } while (seqlock_read_retry(&timers_state.vm_clock_seqlock, start));
-
-    return icount;
-}
-
-int64_t icount_to_ns(int64_t icount)
-{
-    return icount << qatomic_read(&timers_state.icount_time_shift);
-}
-
-/*
- * Correlation between real and virtual time is always going to be
- * fairly approximate, so ignore small variation.
- * When the guest is idle real and virtual time will be aligned in
- * the IO wait loop.
- */
-#define ICOUNT_WOBBLE (NANOSECONDS_PER_SECOND / 10)
-
-static void icount_adjust(void)
-{
-    int64_t cur_time;
-    int64_t cur_icount;
-    int64_t delta;
-
-    /* If the VM is not running, then do nothing.  */
-    if (!runstate_is_running()) {
-        return;
-    }
-
-    seqlock_write_lock(&timers_state.vm_clock_seqlock,
-                       &timers_state.vm_clock_lock);
-    cur_time = REPLAY_CLOCK_LOCKED(REPLAY_CLOCK_VIRTUAL_RT,
-                                   cpu_get_clock_locked());
-    cur_icount = icount_get_locked();
-
-    delta = cur_icount - cur_time;
-    /* FIXME: This is a very crude algorithm, somewhat prone to oscillation.  */
-    if (delta > 0
-        && timers_state.last_delta + ICOUNT_WOBBLE < delta * 2
-        && timers_state.icount_time_shift > 0) {
-        /* The guest is getting too far ahead.  Slow time down.  */
-        qatomic_set(&timers_state.icount_time_shift,
-                    timers_state.icount_time_shift - 1);
-    }
-    if (delta < 0
-        && timers_state.last_delta - ICOUNT_WOBBLE > delta * 2
-        && timers_state.icount_time_shift < MAX_ICOUNT_SHIFT) {
-        /* The guest is getting too far behind.  Speed time up.  */
-        qatomic_set(&timers_state.icount_time_shift,
-                    timers_state.icount_time_shift + 1);
-    }
-    timers_state.last_delta = delta;
-    qatomic_set_i64(&timers_state.qemu_icount_bias,
-                    cur_icount - (timers_state.qemu_icount
-                                  << timers_state.icount_time_shift));
-    seqlock_write_unlock(&timers_state.vm_clock_seqlock,
-                         &timers_state.vm_clock_lock);
-}
-
-static void icount_adjust_rt(void *opaque)
-{
-    timer_mod(timers_state.icount_rt_timer,
-              qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL_RT) + 1000);
-    icount_adjust();
-}
-
-static void icount_adjust_vm(void *opaque)
-{
-    timer_mod(timers_state.icount_vm_timer,
-                   qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
-                   NANOSECONDS_PER_SECOND / 10);
-    icount_adjust();
-}
-
-int64_t icount_round(int64_t count)
-{
-    int shift = qatomic_read(&timers_state.icount_time_shift);
-    return (count + (1 << shift) - 1) >> shift;
-}
-
-static void icount_warp_rt(void)
-{
-    unsigned seq;
-    int64_t warp_start;
-
-    /*
-     * The icount_warp_timer is rescheduled soon after vm_clock_warp_start
-     * changes from -1 to another value, so the race here is okay.
-     */
-    do {
-        seq = seqlock_read_begin(&timers_state.vm_clock_seqlock);
-        warp_start = timers_state.vm_clock_warp_start;
-    } while (seqlock_read_retry(&timers_state.vm_clock_seqlock, seq));
-
-    if (warp_start == -1) {
-        return;
-    }
-
-    seqlock_write_lock(&timers_state.vm_clock_seqlock,
-                       &timers_state.vm_clock_lock);
-    if (runstate_is_running()) {
-        int64_t clock = REPLAY_CLOCK_LOCKED(REPLAY_CLOCK_VIRTUAL_RT,
-                                            cpu_get_clock_locked());
-        int64_t warp_delta;
-
-        warp_delta = clock - timers_state.vm_clock_warp_start;
-        if (icount_enabled() == 2) {
-            /*
-             * In adaptive mode, do not let QEMU_CLOCK_VIRTUAL run too far
-             * ahead of real time (it might already be ahead so careful not
-             * to go backwards).
-             */
-            int64_t cur_icount = icount_get_locked();
-            int64_t delta = clock - cur_icount;
-
-            if (delta < 0) {
-                delta = 0;
-            }
-            warp_delta = MIN(warp_delta, delta);
-        }
-        qatomic_set_i64(&timers_state.qemu_icount_bias,
-                        timers_state.qemu_icount_bias + warp_delta);
-    }
-    timers_state.vm_clock_warp_start = -1;
-    seqlock_write_unlock(&timers_state.vm_clock_seqlock,
-                       &timers_state.vm_clock_lock);
-
-    if (qemu_clock_expired(QEMU_CLOCK_VIRTUAL)) {
-        qemu_clock_notify(QEMU_CLOCK_VIRTUAL);
-    }
-}
-
-static void icount_timer_cb(void *opaque)
-{
-    /*
-     * No need for a checkpoint because the timer already synchronizes
-     * with CHECKPOINT_CLOCK_VIRTUAL_RT.
-     */
-    icount_warp_rt();
-}
-
-void icount_start_warp_timer(void)
-{
-    int64_t clock;
-    int64_t deadline;
-
-    assert(icount_enabled());
-
-    /*
-     * Nothing to do if the VM is stopped: QEMU_CLOCK_VIRTUAL timers
-     * do not fire, so computing the deadline does not make sense.
-     */
-    if (!runstate_is_running()) {
-        return;
-    }
-
-    if (replay_mode != REPLAY_MODE_PLAY) {
-        if (!all_cpu_threads_idle()) {
-            return;
-        }
-
-        if (qtest_enabled()) {
-            /* When testing, qtest commands advance icount.  */
-            return;
-        }
-
-        replay_checkpoint(CHECKPOINT_CLOCK_WARP_START);
-    } else {
-        /* warp clock deterministically in record/replay mode */
-        if (!replay_checkpoint(CHECKPOINT_CLOCK_WARP_START)) {
-            /*
-             * vCPU is sleeping and warp can't be started.
-             * It is probably a race condition: notification sent
-             * to vCPU was processed in advance and vCPU went to sleep.
-             * Therefore we have to wake it up for doing something.
-             */
-            if (replay_has_event()) {
-                qemu_clock_notify(QEMU_CLOCK_VIRTUAL);
-            }
-            return;
-        }
-    }
-
-    /* We want to use the earliest deadline from ALL vm_clocks */
-    clock = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL_RT);
-    deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL,
-                                          ~QEMU_TIMER_ATTR_EXTERNAL);
-    if (deadline < 0) {
-        static bool notified;
-        if (!icount_sleep && !notified) {
-            warn_report("icount sleep disabled and no active timers");
-            notified = true;
-        }
-        return;
-    }
-
-    if (deadline > 0) {
-        /*
-         * Ensure QEMU_CLOCK_VIRTUAL proceeds even when the virtual CPU goes to
-         * sleep.  Otherwise, the CPU might be waiting for a future timer
-         * interrupt to wake it up, but the interrupt never comes because
-         * the vCPU isn't running any insns and thus doesn't advance the
-         * QEMU_CLOCK_VIRTUAL.
-         */
-        if (!icount_sleep) {
-            /*
-             * We never let VCPUs sleep in no sleep icount mode.
-             * If there is a pending QEMU_CLOCK_VIRTUAL timer we just advance
-             * to the next QEMU_CLOCK_VIRTUAL event and notify it.
-             * It is useful when we want a deterministic execution time,
-             * isolated from host latencies.
-             */
-            seqlock_write_lock(&timers_state.vm_clock_seqlock,
-                               &timers_state.vm_clock_lock);
-            qatomic_set_i64(&timers_state.qemu_icount_bias,
-                            timers_state.qemu_icount_bias + deadline);
-            seqlock_write_unlock(&timers_state.vm_clock_seqlock,
-                                 &timers_state.vm_clock_lock);
-            qemu_clock_notify(QEMU_CLOCK_VIRTUAL);
-        } else {
-            /*
-             * We do stop VCPUs and only advance QEMU_CLOCK_VIRTUAL after some
-             * "real" time, (related to the time left until the next event) has
-             * passed. The QEMU_CLOCK_VIRTUAL_RT clock will do this.
-             * This avoids that the warps are visible externally; for example,
-             * you will not be sending network packets continuously instead of
-             * every 100ms.
-             */
-            seqlock_write_lock(&timers_state.vm_clock_seqlock,
-                               &timers_state.vm_clock_lock);
-            if (timers_state.vm_clock_warp_start == -1
-                || timers_state.vm_clock_warp_start > clock) {
-                timers_state.vm_clock_warp_start = clock;
-            }
-            seqlock_write_unlock(&timers_state.vm_clock_seqlock,
-                                 &timers_state.vm_clock_lock);
-            timer_mod_anticipate(timers_state.icount_warp_timer,
-                                 clock + deadline);
-        }
-    } else if (deadline == 0) {
-        qemu_clock_notify(QEMU_CLOCK_VIRTUAL);
-    }
-}
-
-void icount_account_warp_timer(void)
-{
-    if (!icount_sleep) {
-        return;
-    }
-
-    /*
-     * Nothing to do if the VM is stopped: QEMU_CLOCK_VIRTUAL timers
-     * do not fire, so computing the deadline does not make sense.
-     */
-    if (!runstate_is_running()) {
-        return;
-    }
-
-    replay_async_events();
-
-    /* warp clock deterministically in record/replay mode */
-    if (!replay_checkpoint(CHECKPOINT_CLOCK_WARP_ACCOUNT)) {
-        return;
-    }
-
-    timer_del(timers_state.icount_warp_timer);
-    icount_warp_rt();
-}
-
-void icount_configure(QemuOpts *opts, Error **errp)
-{
-    const char *option = qemu_opt_get(opts, "shift");
-    bool sleep = qemu_opt_get_bool(opts, "sleep", true);
-    bool align = qemu_opt_get_bool(opts, "align", false);
-    long time_shift = -1;
-
-    if (!option) {
-        if (qemu_opt_get(opts, "align") != NULL) {
-            error_setg(errp, "Please specify shift option when using align");
-        }
-        return;
-    }
-
-    if (align && !sleep) {
-        error_setg(errp, "align=on and sleep=off are incompatible");
-        return;
-    }
-
-    if (strcmp(option, "auto") != 0) {
-        if (qemu_strtol(option, NULL, 0, &time_shift) < 0
-            || time_shift < 0 || time_shift > MAX_ICOUNT_SHIFT) {
-            error_setg(errp, "icount: Invalid shift value");
-            return;
-        }
-    } else if (icount_align_option) {
-        error_setg(errp, "shift=auto and align=on are incompatible");
-        return;
-    } else if (!icount_sleep) {
-        error_setg(errp, "shift=auto and sleep=off are incompatible");
-        return;
-    }
-
-    icount_sleep = sleep;
-    if (icount_sleep) {
-        timers_state.icount_warp_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL_RT,
-                                         icount_timer_cb, NULL);
-    }
-
-    icount_align_option = align;
-
-    if (time_shift >= 0) {
-        timers_state.icount_time_shift = time_shift;
-        icount_enable_precise();
-        return;
-    }
-
-    icount_enable_adaptive();
-
-    /*
-     * 125MIPS seems a reasonable initial guess at the guest speed.
-     * It will be corrected fairly quickly anyway.
-     */
-    timers_state.icount_time_shift = 3;
-
-    /*
-     * Have both realtime and virtual time triggers for speed adjustment.
-     * The realtime trigger catches emulated time passing too slowly,
-     * the virtual time trigger catches emulated time passing too fast.
-     * Realtime triggers occur even when idle, so use them less frequently
-     * than VM triggers.
-     */
-    timers_state.vm_clock_warp_start = -1;
-    timers_state.icount_rt_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL_RT,
-                                   icount_adjust_rt, NULL);
-    timer_mod(timers_state.icount_rt_timer,
-                   qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL_RT) + 1000);
-    timers_state.icount_vm_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
-                                        icount_adjust_vm, NULL);
-    timer_mod(timers_state.icount_vm_timer,
-                   qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
-                   NANOSECONDS_PER_SECOND / 10);
-}
-
-void icount_notify_exit(void)
-{
-    if (icount_enabled() && current_cpu) {
-        qemu_cpu_kick(current_cpu);
-        qemu_clock_notify(QEMU_CLOCK_VIRTUAL);
-    }
-}
diff --git a/softmmu/meson.build b/softmmu/meson.build
index c18b7ad738..3a64dd89de 100644
--- a/softmmu/meson.build
+++ b/softmmu/meson.build
@@ -6,10 +6,6 @@ specific_ss.add(when: 'CONFIG_SYSTEM_ONLY', if_true: [files(
   'watchpoint.c',
 )])
 
-specific_ss.add(when: ['CONFIG_SYSTEM_ONLY', 'CONFIG_TCG'], if_true: [files(
-  'icount.c',
-)])
-
 system_ss.add(files(
   'balloon.c',
   'bootdevice.c',