diff options
37 files changed, 1128 insertions, 843 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index b76fb31861..a59be84de6 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2321,6 +2321,8 @@ F: softmmu/vl.c F: softmmu/main.c F: softmmu/cpus.c F: softmmu/cpu-throttle.c +F: softmmu/cpu-timers.c +F: softmmu/icount.c F: qapi/run-state.json Read, Copy, Update (RCU) diff --git a/accel/qtest.c b/accel/qtest.c index 5b88f55921..119d0f16a4 100644 --- a/accel/qtest.c +++ b/accel/qtest.c @@ -19,14 +19,10 @@ #include "sysemu/accel.h" #include "sysemu/qtest.h" #include "sysemu/cpus.h" +#include "sysemu/cpu-timers.h" static int qtest_init_accel(MachineState *ms) { - QemuOpts *opts = qemu_opts_create(qemu_find_opts("icount"), NULL, 0, - &error_abort); - qemu_opt_set(opts, "shift", "0", &error_abort); - configure_icount(opts, &error_abort); - qemu_opts_del(opts); return 0; } diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c index e10b46283c..35bfe2ca92 100644 --- a/accel/tcg/cpu-exec.c +++ b/accel/tcg/cpu-exec.c @@ -19,6 +19,7 @@ #include "qemu/osdep.h" #include "qemu-common.h" +#include "qemu/qemu-print.h" #include "cpu.h" #include "trace.h" #include "disas/disas.h" @@ -36,6 +37,8 @@ #include "hw/i386/apic.h" #endif #include "sysemu/cpus.h" +#include "exec/cpu-all.h" +#include "sysemu/cpu-timers.h" #include "sysemu/replay.h" /* -icount align implementation. */ @@ -56,6 +59,9 @@ typedef struct SyncClocks { #define MAX_DELAY_PRINT_RATE 2000000000LL #define MAX_NB_PRINTS 100 +static int64_t max_delay; +static int64_t max_advance; + static void align_clocks(SyncClocks *sc, CPUState *cpu) { int64_t cpu_icount; @@ -98,9 +104,9 @@ static void print_delay(const SyncClocks *sc) (-sc->diff_clk / (float)1000000000LL < (threshold_delay - THRESHOLD_REDUCE))) { threshold_delay = (-sc->diff_clk / 1000000000LL) + 1; - printf("Warning: The guest is now late by %.1f to %.1f seconds\n", - threshold_delay - 1, - threshold_delay); + qemu_printf("Warning: The guest is now late by %.1f to %.1f seconds\n", + threshold_delay - 1, + threshold_delay); nb_prints++; last_realtime_clock = sc->realtime_clock; } @@ -615,7 +621,7 @@ static inline bool cpu_handle_interrupt(CPUState *cpu, /* Finally, check if we need to exit to the main loop. */ if (unlikely(qatomic_read(&cpu->exit_request)) - || (use_icount + || (icount_enabled() && cpu_neg(cpu)->icount_decr.u16.low + cpu->icount_extra == 0)) { qatomic_set(&cpu->exit_request, 0); if (cpu->exception_index == -1) { @@ -656,7 +662,7 @@ static inline void cpu_loop_exec_tb(CPUState *cpu, TranslationBlock *tb, } /* Instruction counter expired. */ - assert(use_icount); + assert(icount_enabled()); #ifndef CONFIG_USER_ONLY /* Ensure global icount has gone forward */ cpu_update_icount(cpu); @@ -759,3 +765,26 @@ int cpu_exec(CPUState *cpu) return ret; } + +#ifndef CONFIG_USER_ONLY + +void dump_drift_info(void) +{ + if (!icount_enabled()) { + return; + } + + qemu_printf("Host - Guest clock %"PRIi64" ms\n", + (cpu_get_clock() - cpu_get_icount()) / SCALE_MS); + if (icount_align_option) { + qemu_printf("Max guest delay %"PRIi64" ms\n", + -max_delay / SCALE_MS); + qemu_printf("Max guest advance %"PRIi64" ms\n", + max_advance / SCALE_MS); + } else { + qemu_printf("Max guest delay NA\n"); + qemu_printf("Max guest advance NA\n"); + } +} + +#endif /* !CONFIG_USER_ONLY */ diff --git a/accel/tcg/tcg-all.c b/accel/tcg/tcg-all.c index 1c664924d7..2d13df3f72 100644 --- a/accel/tcg/tcg-all.c +++ b/accel/tcg/tcg-all.c @@ -29,6 +29,7 @@ #include "qom/object.h" #include "cpu.h" #include "sysemu/cpus.h" +#include "sysemu/cpu-timers.h" #include "qemu/main-loop.h" #include "tcg/tcg.h" #include "qapi/error.h" @@ -66,7 +67,7 @@ static void tcg_handle_interrupt(CPUState *cpu, int mask) qemu_cpu_kick(cpu); } else { qatomic_set(&cpu_neg(cpu)->icount_decr.u16.high, -1); - if (use_icount && + if (icount_enabled() && !cpu->can_do_io && (mask & ~old_mask) != 0) { cpu_abort(cpu, "Raised interrupt while not in I/O function"); @@ -105,7 +106,7 @@ static bool check_tcg_memory_orders_compatible(void) static bool default_mttcg_enabled(void) { - if (use_icount || TCG_OVERSIZED_GUEST) { + if (icount_enabled() || TCG_OVERSIZED_GUEST) { return false; } else { #ifdef TARGET_SUPPORTS_MTTCG @@ -147,7 +148,7 @@ static void tcg_set_thread(Object *obj, const char *value, Error **errp) if (strcmp(value, "multi") == 0) { if (TCG_OVERSIZED_GUEST) { error_setg(errp, "No MTTCG when guest word size > hosts"); - } else if (use_icount) { + } else if (icount_enabled()) { error_setg(errp, "No MTTCG when icount is enabled"); } else { #ifndef TARGET_SUPPORTS_MTTCG diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index e82fc35b32..d76097296d 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -57,6 +57,7 @@ #include "qemu/main-loop.h" #include "exec/log.h" #include "sysemu/cpus.h" +#include "sysemu/cpu-timers.h" #include "sysemu/tcg.h" /* #define DEBUG_TB_INVALIDATE */ @@ -369,7 +370,7 @@ static int cpu_restore_state_from_tb(CPUState *cpu, TranslationBlock *tb, found: if (reset_icount && (tb_cflags(tb) & CF_USE_ICOUNT)) { - assert(use_icount); + assert(icount_enabled()); /* Reset the cycle counter to the start of the block and shift if to the number of actually executed instructions */ cpu_neg(cpu)->icount_decr.u16.low += num_insns - i; diff --git a/dma-helpers.c b/dma-helpers.c index 41ef24a63b..03c92e0cc6 100644 --- a/dma-helpers.c +++ b/dma-helpers.c @@ -13,7 +13,7 @@ #include "trace/trace-root.h" #include "qemu/thread.h" #include "qemu/main-loop.h" -#include "sysemu/cpus.h" +#include "sysemu/cpu-timers.h" #include "qemu/range.h" /* #define DEBUG_IOMMU */ @@ -151,7 +151,7 @@ static void dma_blk_cb(void *opaque, int ret) * from several sectors. This code splits all SGs into several * groups. SGs in every group do not overlap. */ - if (mem && use_icount && dbs->dir == DMA_DIRECTION_FROM_DEVICE) { + if (mem && icount_enabled() && dbs->dir == DMA_DIRECTION_FROM_DEVICE) { int i; for (i = 0 ; i < dbs->iov.niov ; ++i) { if (ranges_overlap((intptr_t)dbs->iov.iov[i].iov_base, @@ -102,10 +102,6 @@ uintptr_t qemu_host_page_size; intptr_t qemu_host_page_mask; #if !defined(CONFIG_USER_ONLY) -/* 0 = Do not count executed instructions. - 1 = Precise instruction counting. - 2 = Adaptive rate instruction counting. */ -int use_icount; typedef struct PhysPageEntry PhysPageEntry; diff --git a/hw/core/ptimer.c b/hw/core/ptimer.c index b5a54e2536..c6d2beb1da 100644 --- a/hw/core/ptimer.c +++ b/hw/core/ptimer.c @@ -7,11 +7,11 @@ */ #include "qemu/osdep.h" -#include "qemu/timer.h" #include "hw/ptimer.h" #include "migration/vmstate.h" #include "qemu/host-utils.h" #include "sysemu/replay.h" +#include "sysemu/cpu-timers.h" #include "sysemu/qtest.h" #include "block/aio.h" #include "sysemu/cpus.h" @@ -134,7 +134,8 @@ static void ptimer_reload(ptimer_state *s, int delta_adjust) * on the current generation of host machines. */ - if (s->enabled == 1 && (delta * period < 10000) && !use_icount) { + if (s->enabled == 1 && (delta * period < 10000) && + !icount_enabled() && !qtest_enabled()) { period = 10000 / delta; period_frac = 0; } @@ -217,7 +218,8 @@ uint64_t ptimer_get_count(ptimer_state *s) uint32_t period_frac = s->period_frac; uint64_t period = s->period; - if (!oneshot && (s->delta * period < 10000) && !use_icount) { + if (!oneshot && (s->delta * period < 10000) && + !icount_enabled() && !qtest_enabled()) { period = 10000 / s->delta; period_frac = 0; } diff --git a/hw/i386/x86.c b/hw/i386/x86.c index 403c2b1dad..953083e063 100644 --- a/hw/i386/x86.c +++ b/hw/i386/x86.c @@ -34,6 +34,7 @@ #include "sysemu/numa.h" #include "sysemu/replay.h" #include "sysemu/sysemu.h" +#include "sysemu/cpu-timers.h" #include "trace.h" #include "hw/i386/x86.h" diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h index f6439c4705..61e13b5038 100644 --- a/include/exec/cpu-all.h +++ b/include/exec/cpu-all.h @@ -407,8 +407,12 @@ static inline bool tlb_hit(target_ulong tlb_addr, target_ulong addr) return tlb_hit_page(tlb_addr, addr & TARGET_PAGE_MASK); } +#ifdef CONFIG_TCG +void dump_drift_info(void); void dump_exec_info(void); void dump_opcount_info(void); +#endif /* CONFIG_TCG */ + #endif /* !CONFIG_USER_ONLY */ /* Returns: 0 on success, -1 on error */ diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index 1fe28d574f..66f9b4cca6 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -25,7 +25,7 @@ #ifdef CONFIG_TCG #include "exec/cpu_ldst.h" #endif -#include "sysemu/cpus.h" +#include "sysemu/cpu-timers.h" /* allow to see translation results - the slowdown should be negligible, so we leave it */ #define DEBUG_DISAS @@ -497,7 +497,7 @@ static inline uint32_t tb_cflags(const TranslationBlock *tb) static inline uint32_t curr_cflags(void) { return (parallel_cpus ? CF_PARALLEL : 0) - | (use_icount ? CF_USE_ICOUNT : 0); + | (icount_enabled() ? CF_USE_ICOUNT : 0); } /* TranslationBlock invalidate API */ diff --git a/include/qemu/timer.h b/include/qemu/timer.h index 1dc880e94e..bdecc5b41f 100644 --- a/include/qemu/timer.h +++ b/include/qemu/timer.h @@ -166,8 +166,8 @@ bool qemu_clock_expired(QEMUClockType 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 + * icount_enabled() 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. * @@ -225,13 +225,6 @@ void qemu_clock_notify(QEMUClockType type); 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 * @@ -791,12 +784,6 @@ static inline int64_t qemu_soonest_timeout(int64_t timeout1, int64_t timeout2) */ 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 @@ -850,13 +837,6 @@ static inline int64_t get_clock(void) } #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) */ diff --git a/include/sysemu/cpu-timers.h b/include/sysemu/cpu-timers.h new file mode 100644 index 0000000000..4b621fea51 --- /dev/null +++ b/include/sysemu/cpu-timers.h @@ -0,0 +1,87 @@ +/* + * CPU timers state API + * + * Copyright 2020 SUSE LLC + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + */ +#ifndef SYSEMU_CPU_TIMERS_H +#define SYSEMU_CPU_TIMERS_H + +#include "qemu/timer.h" + +/* init the whole cpu timers API, including icount, ticks, and cpu_throttle */ +void cpu_timers_init(void); + +/* icount - Instruction Counter API */ + +/* + * icount enablement state: + * + * 0 = Disabled - Do not count executed instructions. + * 1 = Enabled - Fixed conversion of insn to ns via "shift" option + * 2 = Enabled - Runtime adaptive algorithm to compute shift + */ +#ifdef CONFIG_TCG +extern int use_icount; +#define icount_enabled() (use_icount) +#else +#define icount_enabled() 0 +#endif + +/* + * Update the icount with the executed instructions. Called by + * cpus-tcg vCPU thread so the main-loop can see time has moved forward. + */ +void cpu_update_icount(CPUState *cpu); + +/* get raw icount value */ +int64_t cpu_get_icount_raw(void); + +/* return the virtual CPU time in ns, based on the instruction counter. */ +int64_t cpu_get_icount(void); +/* + * convert an instruction counter value to ns, based on the icount shift. + * This shift is set as a fixed value with the icount "shift" option + * (precise mode), or it is constantly approximated and corrected at + * runtime in adaptive mode. + */ +int64_t cpu_icount_to_ns(int64_t icount); + +/* configure the icount options, including "shift" */ +void configure_icount(QemuOpts *opts, Error **errp); + +/* used by tcg vcpu thread to calc icount budget */ +int64_t qemu_icount_round(int64_t count); + +/* if the CPUs are idle, start accounting real time to virtual clock. */ +void qemu_start_warp_timer(void); +void qemu_account_warp_timer(void); + +/* + * CPU Ticks and Clock + */ + +/* Caller must hold BQL */ +void cpu_enable_ticks(void); +/* Caller must hold BQL */ +void cpu_disable_ticks(void); + +/* + * return the time elapsed in VM between vm_start and vm_stop. Unless + * icount is active, cpu_get_ticks() uses units of the host CPU cycle + * counter. + */ +int64_t cpu_get_ticks(void); + +/* + * Returns the monotonic time elapsed in VM, i.e., + * the time between vm_start and vm_stop + */ +int64_t cpu_get_clock(void); + +void qemu_timer_notify_cb(void *opaque, QEMUClockType type); + +#endif /* SYSEMU_CPU_TIMERS_H */ diff --git a/include/sysemu/cpus.h b/include/sysemu/cpus.h index 3c1da6a018..149de000a0 100644 --- a/include/sysemu/cpus.h +++ b/include/sysemu/cpus.h @@ -4,33 +4,23 @@ #include "qemu/timer.h" /* cpus.c */ +bool all_cpu_threads_idle(void); bool qemu_in_vcpu_thread(void); void qemu_init_cpu_loop(void); void resume_all_vcpus(void); void pause_all_vcpus(void); void cpu_stop_current(void); -void cpu_ticks_init(void); -void configure_icount(QemuOpts *opts, Error **errp); -extern int use_icount; extern int icount_align_option; -/* drift information for info jit command */ -extern int64_t max_delay; -extern int64_t max_advance; -void dump_drift_info(void); - /* Unblock cpu */ void qemu_cpu_kick_self(void); -void qemu_timer_notify_cb(void *opaque, QEMUClockType type); void cpu_synchronize_all_states(void); void cpu_synchronize_all_post_reset(void); void cpu_synchronize_all_post_init(void); void cpu_synchronize_all_pre_loadvm(void); -void qtest_clock_warp(int64_t dest); - #ifndef CONFIG_USER_ONLY /* vl.c */ /* *-user doesn't have configurable SMP topology */ diff --git a/include/sysemu/qtest.h b/include/sysemu/qtest.h index eedd3664f0..4c53537ef3 100644 --- a/include/sysemu/qtest.h +++ b/include/sysemu/qtest.h @@ -30,4 +30,6 @@ void qtest_server_set_send_handler(void (*send)(void *, const char *), void *opaque); void qtest_server_inproc_recv(void *opaque, const char *buf); +int64_t qtest_get_virtual_clock(void); + #endif diff --git a/replay/replay.c b/replay/replay.c index 83ed9e0e24..7e4a1ba78e 100644 --- a/replay/replay.c +++ b/replay/replay.c @@ -11,10 +11,10 @@ #include "qemu/osdep.h" #include "qapi/error.h" +#include "sysemu/cpu-timers.h" #include "sysemu/replay.h" #include "sysemu/runstate.h" #include "replay-internal.h" -#include "qemu/timer.h" #include "qemu/main-loop.h" #include "qemu/option.h" #include "sysemu/cpus.h" @@ -345,7 +345,7 @@ void replay_start(void) error_reportf_err(replay_blockers->data, "Record/replay: "); exit(1); } - if (!use_icount) { + if (!icount_enabled()) { error_report("Please enable icount to use record/replay"); exit(1); } diff --git a/softmmu/cpu-timers.c b/softmmu/cpu-timers.c new file mode 100644 index 0000000000..6c6c56090f --- /dev/null +++ b/softmmu/cpu-timers.c @@ -0,0 +1,284 @@ +/* + * 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-common.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" + +/* clock and ticks */ + +static int64_t cpu_get_ticks_locked(void) +{ + int64_t ticks = timers_state.cpu_ticks_offset; + if (timers_state.cpu_ticks_enabled) { + ticks += cpu_get_host_ticks(); + } + + if (timers_state.cpu_ticks_prev > ticks) { + /* Non increasing ticks may happen if the host uses software suspend. */ + timers_state.cpu_ticks_offset += timers_state.cpu_ticks_prev - ticks; + ticks = timers_state.cpu_ticks_prev; + } + + timers_state.cpu_ticks_prev = ticks; + return ticks; +} + +/* + * return the time elapsed in VM between vm_start and vm_stop. Unless + * icount is active, cpu_get_ticks() uses units of the host CPU cycle + * counter. + */ +int64_t cpu_get_ticks(void) +{ + int64_t ticks; + + if (icount_enabled()) { + return cpu_get_icount(); + } + + qemu_spin_lock(&timers_state.vm_clock_lock); + ticks = cpu_get_ticks_locked(); + qemu_spin_unlock(&timers_state.vm_clock_lock); + return ticks; +} + +int64_t cpu_get_clock_locked(void) +{ + int64_t time; + + time = timers_state.cpu_clock_offset; + if (timers_state.cpu_ticks_enabled) { + time += get_clock(); + } + + return time; +} + +/* + * Return the monotonic time elapsed in VM, i.e., + * the time between vm_start and vm_stop + */ +int64_t cpu_get_clock(void) +{ + int64_t ti; + unsigned start; + + do { + start = seqlock_read_begin(&timers_state.vm_clock_seqlock); + ti = cpu_get_clock_locked(); + } while (seqlock_read_retry(&timers_state.vm_clock_seqlock, start)); + + return ti; +} + +/* + * enable cpu_get_ticks() + * Caller must hold BQL which serves as mutex for vm_clock_seqlock. + */ +void cpu_enable_ticks(void) +{ + seqlock_write_lock(&timers_state.vm_clock_seqlock, + &timers_state.vm_clock_lock); + if (!timers_state.cpu_ticks_enabled) { + timers_state.cpu_ticks_offset -= cpu_get_host_ticks(); + timers_state.cpu_clock_offset -= get_clock(); + timers_state.cpu_ticks_enabled = 1; + } + seqlock_write_unlock(&timers_state.vm_clock_seqlock, + &timers_state.vm_clock_lock); +} + +/* + * disable cpu_get_ticks() : the clock is stopped. You must not call + * cpu_get_ticks() after that. + * Caller must hold BQL which serves as mutex for vm_clock_seqlock. + */ +void cpu_disable_ticks(void) +{ + seqlock_write_lock(&timers_state.vm_clock_seqlock, + &timers_state.vm_clock_lock); + if (timers_state.cpu_ticks_enabled) { + timers_state.cpu_ticks_offset += cpu_get_host_ticks(); + timers_state.cpu_clock_offset = cpu_get_clock_locked(); + timers_state.cpu_ticks_enabled = 0; + } + seqlock_write_unlock(&timers_state.vm_clock_seqlock, + &timers_state.vm_clock_lock); +} + +static bool icount_state_needed(void *opaque) +{ + return icount_enabled(); +} + +static bool warp_timer_state_needed(void *opaque) +{ + TimersState *s = opaque; + return s->icount_warp_timer != NULL; +} + +static bool adjust_timers_state_needed(void *opaque) +{ + TimersState *s = opaque; + return s->icount_rt_timer != NULL; +} + +static bool shift_state_needed(void *opaque) +{ + return icount_enabled() == 2; +} + +/* + * Subsection for warp timer migration is optional, because may not be created + */ +static const VMStateDescription icount_vmstate_warp_timer = { + .name = "timer/icount/warp_timer", + .version_id = 1, + .minimum_version_id = 1, + .needed = warp_timer_state_needed, + .fields = (VMStateField[]) { + VMSTATE_INT64(vm_clock_warp_start, TimersState), + VMSTATE_TIMER_PTR(icount_warp_timer, TimersState), + VMSTATE_END_OF_LIST() + } +}; + +static const VMStateDescription icount_vmstate_adjust_timers = { + .name = "timer/icount/timers", + .version_id = 1, + .minimum_version_id = 1, + .needed = adjust_timers_state_needed, + .fields = (VMStateField[]) { + VMSTATE_TIMER_PTR(icount_rt_timer, TimersState), + VMSTATE_TIMER_PTR(icount_vm_timer, TimersState), + VMSTATE_END_OF_LIST() + } +}; + +static const VMStateDescription icount_vmstate_shift = { + .name = "timer/icount/shift", + .version_id = 1, + .minimum_version_id = 1, + .needed = shift_state_needed, + .fields = (VMStateField[]) { + VMSTATE_INT16(icount_time_shift, TimersState), + VMSTATE_END_OF_LIST() + } +}; + +/* + * This is a subsection for icount migration. + */ +static const VMStateDescription icount_vmstate_timers = { + .name = "timer/icount", + .version_id = 1, + .minimum_version_id = 1, + .needed = icount_state_needed, + .fields = (VMStateField[]) { + VMSTATE_INT64(qemu_icount_bias, TimersState), + VMSTATE_INT64(qemu_icount, TimersState), + VMSTATE_END_OF_LIST() + }, + .subsections = (const VMStateDescription * []) { + &icount_vmstate_warp_timer, + &icount_vmstate_adjust_timers, + &icount_vmstate_shift, + NULL + } +}; + +static const VMStateDescription vmstate_timers = { + .name = "timer", + .version_id = 2, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_INT64(cpu_ticks_offset, TimersState), + VMSTATE_UNUSED(8), + VMSTATE_INT64_V(cpu_clock_offset, TimersState, 2), + VMSTATE_END_OF_LIST() + }, + .subsections = (const VMStateDescription * []) { + &icount_vmstate_timers, + NULL + } +}; + +static void do_nothing(CPUState *cpu, run_on_cpu_data unused) +{ +} + +void qemu_timer_notify_cb(void *opaque, QEMUClockType type) +{ + if (!icount_enabled() || type != QEMU_CLOCK_VIRTUAL) { + qemu_notify_event(); + return; + } + + if (qemu_in_vcpu_thread()) { + /* + * A CPU is currently running; kick it back out to the + * tcg_cpu_exec() loop so it will recalculate its + * icount deadline immediately. + */ + qemu_cpu_kick(current_cpu); + } else if (first_cpu) { + /* + * qemu_cpu_kick is not enough to kick a halted CPU out of + * qemu_tcg_wait_io_event. async_run_on_cpu, instead, + * causes cpu_thread_is_idle to return false. This way, + * handle_icount_deadline can run. + * If we have no CPUs at all for some reason, we don't + * need to do anything. + */ + async_run_on_cpu(first_cpu, do_nothing, RUN_ON_CPU_NULL); + } +} + +TimersState timers_state; + +/* initialize timers state and the cpu throttle for convenience */ +void cpu_timers_init(void) +{ + seqlock_init(&timers_state.vm_clock_seqlock); + qemu_spin_init(&timers_state.vm_clock_lock); + vmstate_register(NULL, 0, &vmstate_timers, &timers_state); + + cpu_throttle_init(); +} diff --git a/softmmu/cpus.c b/softmmu/cpus.c index ac8940d52e..4f2777a738 100644 --- a/softmmu/cpus.c +++ b/softmmu/cpus.c @@ -58,11 +58,10 @@ #include "hw/nmi.h" #include "sysemu/replay.h" #include "sysemu/runstate.h" +#include "sysemu/cpu-timers.h" #include "hw/boards.h" #include "hw/hw.h" -#include "sysemu/cpu-throttle.h" - #ifdef CONFIG_LINUX #include <sys/prctl.h> @@ -83,9 +82,6 @@ static QemuMutex qemu_global_mutex; -int64_t max_delay; -int64_t max_advance; - bool cpu_is_stopped(CPUState *cpu) { return cpu->stopped || !runstate_is_running(); @@ -116,7 +112,7 @@ static bool cpu_thread_is_idle(CPUState *cpu) return true; } -static bool all_cpu_threads_idle(void) +bool all_cpu_threads_idle(void) { CPUState *cpu; @@ -128,688 +124,9 @@ static bool all_cpu_threads_idle(void) return true; } -/***********************************************************/ -/* guest cycle counter */ - -/* Protected by TimersState seqlock */ - -static bool icount_sleep = true; -/* Arbitrarily pick 1MIPS as the minimum allowable speed. */ -#define MAX_ICOUNT_SHIFT 10 - -typedef struct TimersState { - /* Protected by BQL. */ - int64_t cpu_ticks_prev; - int64_t cpu_ticks_offset; - - /* Protect fields that can be respectively read outside the - * BQL, and written from multiple threads. - */ - QemuSeqLock vm_clock_seqlock; - QemuSpin vm_clock_lock; - - int16_t cpu_ticks_enabled; - - /* Conversion factor from emulated instructions to virtual clock ticks. */ - int16_t icount_time_shift; - - /* Compensate for varying guest execution speed. */ - int64_t qemu_icount_bias; - - int64_t vm_clock_warp_start; - int64_t cpu_clock_offset; - - /* Only written by TCG thread */ - int64_t qemu_icount; - - /* for adjusting icount */ - QEMUTimer *icount_rt_timer; - QEMUTimer *icount_vm_timer; - QEMUTimer *icount_warp_timer; -} TimersState; - -static TimersState timers_state; bool mttcg_enabled; -/* 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 cpu_get_icount_executed(CPUState *cpu) -{ - return (cpu->icount_budget - - (cpu_neg(cpu)->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 cpu_update_icount_locked(CPUState *cpu) -{ - int64_t executed = cpu_get_icount_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 cpu_update_icount(CPUState *cpu) -{ - seqlock_write_lock(&timers_state.vm_clock_seqlock, - &timers_state.vm_clock_lock); - cpu_update_icount_locked(cpu); - seqlock_write_unlock(&timers_state.vm_clock_seqlock, - &timers_state.vm_clock_lock); -} - -static int64_t cpu_get_icount_raw_locked(void) -{ - CPUState *cpu = current_cpu; - - if (cpu && cpu->running) { - if (!cpu->can_do_io) { - error_report("Bad icount read"); - exit(1); - } - /* Take into account what has run */ - cpu_update_icount_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 cpu_get_icount_locked(void) -{ - int64_t icount = cpu_get_icount_raw_locked(); - return qatomic_read_i64(&timers_state.qemu_icount_bias) + - cpu_icount_to_ns(icount); -} - -int64_t cpu_get_icount_raw(void) -{ - int64_t icount; - unsigned start; - - do { - start = seqlock_read_begin(&timers_state.vm_clock_seqlock); - icount = cpu_get_icount_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 cpu_get_icount(void) -{ - int64_t icount; - unsigned start; - - do { - start = seqlock_read_begin(&timers_state.vm_clock_seqlock); - icount = cpu_get_icount_locked(); - } while (seqlock_read_retry(&timers_state.vm_clock_seqlock, start)); - - return icount; -} - -int64_t cpu_icount_to_ns(int64_t icount) -{ - return icount << qatomic_read(&timers_state.icount_time_shift); -} - -static int64_t cpu_get_ticks_locked(void) -{ - int64_t ticks = timers_state.cpu_ticks_offset; - if (timers_state.cpu_ticks_enabled) { - ticks += cpu_get_host_ticks(); - } - - if (timers_state.cpu_ticks_prev > ticks) { - /* Non increasing ticks may happen if the host uses software suspend. */ - timers_state.cpu_ticks_offset += timers_state.cpu_ticks_prev - ticks; - ticks = timers_state.cpu_ticks_prev; - } - - timers_state.cpu_ticks_prev = ticks; - return ticks; -} - -/* return the time elapsed in VM between vm_start and vm_stop. Unless - * icount is active, cpu_get_ticks() uses units of the host CPU cycle - * counter. - */ -int64_t cpu_get_ticks(void) -{ - int64_t ticks; - - if (use_icount) { - return cpu_get_icount(); - } - - qemu_spin_lock(&timers_state.vm_clock_lock); - ticks = cpu_get_ticks_locked(); - qemu_spin_unlock(&timers_state.vm_clock_lock); - return ticks; -} - -static int64_t cpu_get_clock_locked(void) -{ - int64_t time; - - time = timers_state.cpu_clock_offset; - if (timers_state.cpu_ticks_enabled) { - time += get_clock(); - } - - return time; -} - -/* Return the monotonic time elapsed in VM, i.e., - * the time between vm_start and vm_stop - */ -int64_t cpu_get_clock(void) -{ - int64_t ti; - unsigned start; - - do { - start = seqlock_read_begin(&timers_state.vm_clock_seqlock); - ti = cpu_get_clock_locked(); - } while (seqlock_read_retry(&timers_state.vm_clock_seqlock, start)); - - return ti; -} - -/* enable cpu_get_ticks() - * Caller must hold BQL which serves as mutex for vm_clock_seqlock. - */ -void cpu_enable_ticks(void) -{ - seqlock_write_lock(&timers_state.vm_clock_seqlock, - &timers_state.vm_clock_lock); - if (!timers_state.cpu_ticks_enabled) { - timers_state.cpu_ticks_offset -= cpu_get_host_ticks(); - timers_state.cpu_clock_offset -= get_clock(); - timers_state.cpu_ticks_enabled = 1; - } - seqlock_write_unlock(&timers_state.vm_clock_seqlock, - &timers_state.vm_clock_lock); -} - -/* disable cpu_get_ticks() : the clock is stopped. You must not call - * cpu_get_ticks() after that. - * Caller must hold BQL which serves as mutex for vm_clock_seqlock. - */ -void cpu_disable_ticks(void) -{ - seqlock_write_lock(&timers_state.vm_clock_seqlock, - &timers_state.vm_clock_lock); - if (timers_state.cpu_ticks_enabled) { - timers_state.cpu_ticks_offset += cpu_get_host_ticks(); - timers_state.cpu_clock_offset = cpu_get_clock_locked(); - timers_state.cpu_ticks_enabled = 0; - } - seqlock_write_unlock(&timers_state.vm_clock_seqlock, - &timers_state.vm_clock_lock); -} - -/* 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; - - /* Protected by TimersState mutex. */ - static int64_t last_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 = cpu_get_icount_locked(); - - delta = cur_icount - cur_time; - /* FIXME: This is a very crude algorithm, somewhat prone to oscillation. */ - if (delta > 0 - && 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 - && 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); - } - 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(); -} - -static int64_t qemu_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 (use_icount == 2) { - /* - * In adaptive mode, do not let QEMU_CLOCK_VIRTUAL run too - * far ahead of real time. - */ - int64_t cur_icount = cpu_get_icount_locked(); - int64_t delta = clock - cur_icount; - 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 qtest_clock_warp(int64_t dest) -{ - int64_t clock = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); - AioContext *aio_context; - assert(qtest_enabled()); - aio_context = qemu_get_aio_context(); - while (clock < dest) { - int64_t deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL, - QEMU_TIMER_ATTR_ALL); - int64_t warp = qemu_soonest_timeout(dest - clock, deadline); - - 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 + warp); - seqlock_write_unlock(&timers_state.vm_clock_seqlock, - &timers_state.vm_clock_lock); - - qemu_clock_run_timers(QEMU_CLOCK_VIRTUAL); - timerlist_run_timers(aio_context->tlg.tl[QEMU_CLOCK_VIRTUAL]); - clock = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); - } - qemu_clock_notify(QEMU_CLOCK_VIRTUAL); -} - -void qemu_start_warp_timer(void) -{ - int64_t clock; - int64_t deadline; - - if (!use_icount) { - 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; - } - - 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 someting. */ - if (replay_has_checkpoint()) { - 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); - } -} - -static void qemu_account_warp_timer(void) -{ - if (!use_icount || !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; - } - - /* 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(); -} - -static bool icount_state_needed(void *opaque) -{ - return use_icount; -} - -static bool warp_timer_state_needed(void *opaque) -{ - TimersState *s = opaque; - return s->icount_warp_timer != NULL; -} - -static bool adjust_timers_state_needed(void *opaque) -{ - TimersState *s = opaque; - return s->icount_rt_timer != NULL; -} - -static bool shift_state_needed(void *opaque) -{ - return use_icount == 2; -} - -/* - * Subsection for warp timer migration is optional, because may not be created - */ -static const VMStateDescription icount_vmstate_warp_timer = { - .name = "timer/icount/warp_timer", - .version_id = 1, - .minimum_version_id = 1, - .needed = warp_timer_state_needed, - .fields = (VMStateField[]) { - VMSTATE_INT64(vm_clock_warp_start, TimersState), - VMSTATE_TIMER_PTR(icount_warp_timer, TimersState), - VMSTATE_END_OF_LIST() - } -}; - -static const VMStateDescription icount_vmstate_adjust_timers = { - .name = "timer/icount/timers", - .version_id = 1, - .minimum_version_id = 1, - .needed = adjust_timers_state_needed, - .fields = (VMStateField[]) { - VMSTATE_TIMER_PTR(icount_rt_timer, TimersState), - VMSTATE_TIMER_PTR(icount_vm_timer, TimersState), - VMSTATE_END_OF_LIST() - } -}; - -static const VMStateDescription icount_vmstate_shift = { - .name = "timer/icount/shift", - .version_id = 1, - .minimum_version_id = 1, - .needed = shift_state_needed, - .fields = (VMStateField[]) { - VMSTATE_INT16(icount_time_shift, TimersState), - VMSTATE_END_OF_LIST() - } -}; - -/* - * This is a subsection for icount migration. - */ -static const VMStateDescription icount_vmstate_timers = { - .name = "timer/icount", - .version_id = 1, - .minimum_version_id = 1, - .needed = icount_state_needed, - .fields = (VMStateField[]) { - VMSTATE_INT64(qemu_icount_bias, TimersState), - VMSTATE_INT64(qemu_icount, TimersState), - VMSTATE_END_OF_LIST() - }, - .subsections = (const VMStateDescription*[]) { - &icount_vmstate_warp_timer, - &icount_vmstate_adjust_timers, - &icount_vmstate_shift, - NULL - } -}; - -static const VMStateDescription vmstate_timers = { - .name = "timer", - .version_id = 2, - .minimum_version_id = 1, - .fields = (VMStateField[]) { - VMSTATE_INT64(cpu_ticks_offset, TimersState), - VMSTATE_UNUSED(8), - VMSTATE_INT64_V(cpu_clock_offset, TimersState, 2), - VMSTATE_END_OF_LIST() - }, - .subsections = (const VMStateDescription*[]) { - &icount_vmstate_timers, - NULL - } -}; - -void cpu_ticks_init(void) -{ - seqlock_init(&timers_state.vm_clock_seqlock); - qemu_spin_init(&timers_state.vm_clock_lock); - vmstate_register(NULL, 0, &vmstate_timers, &timers_state); - cpu_throttle_init(); -} - -void configure_icount(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; - use_icount = 1; - return; - } - - use_icount = 2; - - /* 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); -} - /***********************************************************/ /* TCG vCPU kick timer * @@ -854,35 +171,6 @@ static void qemu_cpu_kick_rr_cpus(void) }; } -static void do_nothing(CPUState *cpu, run_on_cpu_data unused) -{ -} - -void qemu_timer_notify_cb(void *opaque, QEMUClockType type) -{ - if (!use_icount || type != QEMU_CLOCK_VIRTUAL) { - qemu_notify_event(); - return; - } - - if (qemu_in_vcpu_thread()) { - /* A CPU is currently running; kick it back out to the - * tcg_cpu_exec() loop so it will recalculate its - * icount deadline immediately. - */ - qemu_cpu_kick(current_cpu); - } else if (first_cpu) { - /* qemu_cpu_kick is not enough to kick a halted CPU out of - * qemu_tcg_wait_io_event. async_run_on_cpu, instead, - * causes cpu_thread_is_idle to return false. This way, - * handle_icount_deadline can run. - * If we have no CPUs at all for some reason, we don't - * need to do anything. - */ - async_run_on_cpu(first_cpu, do_nothing, RUN_ON_CPU_NULL); - } -} - static void kick_tcg_thread(void *opaque) { timer_mod(tcg_kick_vcpu_timer, qemu_tcg_next_kick()); @@ -1288,7 +576,7 @@ static void notify_aio_contexts(void) static void handle_icount_deadline(void) { assert(qemu_in_vcpu_thread()); - if (use_icount) { + if (icount_enabled()) { int64_t deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL, QEMU_TIMER_ATTR_ALL); @@ -1300,7 +588,7 @@ static void handle_icount_deadline(void) static void prepare_icount_for_run(CPUState *cpu) { - if (use_icount) { + if (icount_enabled()) { int insns_left; /* These should always be cleared by process_icount_data after @@ -1325,7 +613,7 @@ static void prepare_icount_for_run(CPUState *cpu) static void process_icount_data(CPUState *cpu) { - if (use_icount) { + if (icount_enabled()) { /* Account for executed instructions */ cpu_update_icount(cpu); @@ -1486,7 +774,7 @@ static void *qemu_tcg_rr_cpu_thread_fn(void *arg) qatomic_mb_set(&cpu->exit_request, 0); } - if (use_icount && all_cpu_threads_idle()) { + if (icount_enabled() && all_cpu_threads_idle()) { /* * When all cpus are sleeping (e.g in WFI), to avoid a deadlock * in the main_loop, wake it up in order to start the warp timer. @@ -1639,7 +927,7 @@ static void *qemu_tcg_cpu_thread_fn(void *arg) CPUState *cpu = arg; assert(tcg_enabled()); - g_assert(!use_icount); + g_assert(!icount_enabled()); rcu_register_thread(); tcg_register_thread(); @@ -2227,21 +1515,3 @@ void qmp_inject_nmi(Error **errp) nmi_monitor_handle(monitor_get_cpu_index(), errp); } -void dump_drift_info(void) -{ - if (!use_icount) { - return; - } - - qemu_printf("Host - Guest clock %"PRIi64" ms\n", - (cpu_get_clock() - cpu_get_icount())/SCALE_MS); - if (icount_align_option) { - qemu_printf("Max guest delay %"PRIi64" ms\n", - -max_delay / SCALE_MS); - qemu_printf("Max guest advance %"PRIi64" ms\n", - max_advance / SCALE_MS); - } else { - qemu_printf("Max guest delay NA\n"); - qemu_printf("Max guest advance NA\n"); - } -} diff --git a/softmmu/icount.c b/softmmu/icount.c new file mode 100644 index 0000000000..0b815fe88f --- /dev/null +++ b/softmmu/icount.c @@ -0,0 +1,492 @@ +/* + * 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-common.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 cpu_get_icount_executed(CPUState *cpu) +{ + return (cpu->icount_budget - + (cpu_neg(cpu)->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 cpu_update_icount_locked(CPUState *cpu) +{ + int64_t executed = cpu_get_icount_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 cpu_update_icount(CPUState *cpu) +{ + seqlock_write_lock(&timers_state.vm_clock_seqlock, + &timers_state.vm_clock_lock); + cpu_update_icount_locked(cpu); + seqlock_write_unlock(&timers_state.vm_clock_seqlock, + &timers_state.vm_clock_lock); +} + +static int64_t cpu_get_icount_raw_locked(void) +{ + CPUState *cpu = current_cpu; + + if (cpu && cpu->running) { + if (!cpu->can_do_io) { + error_report("Bad icount read"); + exit(1); + } + /* Take into account what has run */ + cpu_update_icount_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 cpu_get_icount_locked(void) +{ + int64_t icount = cpu_get_icount_raw_locked(); + return qatomic_read_i64(&timers_state.qemu_icount_bias) + + cpu_icount_to_ns(icount); +} + +int64_t cpu_get_icount_raw(void) +{ + int64_t icount; + unsigned start; + + do { + start = seqlock_read_begin(&timers_state.vm_clock_seqlock); + icount = cpu_get_icount_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 cpu_get_icount(void) +{ + int64_t icount; + unsigned start; + + do { + start = seqlock_read_begin(&timers_state.vm_clock_seqlock); + icount = cpu_get_icount_locked(); + } while (seqlock_read_retry(&timers_state.vm_clock_seqlock, start)); + + return icount; +} + +int64_t cpu_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; + + /* Protected by TimersState mutex. */ + static int64_t last_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 = cpu_get_icount_locked(); + + delta = cur_icount - cur_time; + /* FIXME: This is a very crude algorithm, somewhat prone to oscillation. */ + if (delta > 0 + && 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 + && 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); + } + 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 qemu_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. + */ + int64_t cur_icount = cpu_get_icount_locked(); + int64_t delta = clock - cur_icount; + 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 qemu_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 someting. + */ + if (replay_has_checkpoint()) { + 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 qemu_account_warp_timer(void) +{ + if (!icount_enabled() || !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; + } + + /* 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 configure_icount(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); +} diff --git a/softmmu/meson.build b/softmmu/meson.build index 95d38df259..36c96e7b15 100644 --- a/softmmu/meson.build +++ b/softmmu/meson.build @@ -1,4 +1,4 @@ -specific_ss.add(when: 'CONFIG_SOFTMMU', if_true: files( +specific_ss.add(when: 'CONFIG_SOFTMMU', if_true: [files( 'arch_init.c', 'balloon.c', 'cpus.c', @@ -7,4 +7,10 @@ specific_ss.add(when: 'CONFIG_SOFTMMU', if_true: files( 'memory.c', 'memory_mapping.c', 'qtest.c', - 'vl.c')) + 'vl.c', + 'cpu-timers.c', +)]) + +specific_ss.add(when: ['CONFIG_SOFTMMU', 'CONFIG_TCG'], if_true: [files( + 'icount.c' +)]) diff --git a/softmmu/qtest.c b/softmmu/qtest.c index 4e439caec7..0d43cf8883 100644 --- a/softmmu/qtest.c +++ b/softmmu/qtest.c @@ -21,7 +21,7 @@ #include "exec/memory.h" #include "hw/irq.h" #include "sysemu/accel.h" -#include "sysemu/cpus.h" +#include "sysemu/cpu-timers.h" #include "qemu/config-file.h" #include "qemu/option.h" #include "qemu/error-report.h" @@ -273,6 +273,38 @@ static void qtest_irq_handler(void *opaque, int n, int level) } } +static int64_t qtest_clock_counter; + +int64_t qtest_get_virtual_clock(void) +{ + return qatomic_read_i64(&qtest_clock_counter); +} + +static void qtest_set_virtual_clock(int64_t count) +{ + qatomic_set_i64(&qtest_clock_counter, count); +} + +static void qtest_clock_warp(int64_t dest) +{ + int64_t clock = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); + AioContext *aio_context; + assert(qtest_enabled()); + aio_context = qemu_get_aio_context(); + while (clock < dest) { + int64_t deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL, + QEMU_TIMER_ATTR_ALL); + int64_t warp = qemu_soonest_timeout(dest - clock, deadline); + + qtest_set_virtual_clock(qtest_get_virtual_clock() + warp); + + qemu_clock_run_timers(QEMU_CLOCK_VIRTUAL); + timerlist_run_timers(aio_context->tlg.tl[QEMU_CLOCK_VIRTUAL]); + clock = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); + } + qemu_clock_notify(QEMU_CLOCK_VIRTUAL); +} + static void qtest_process_command(CharBackend *chr, gchar **words) { const gchar *command; diff --git a/softmmu/timers-state.h b/softmmu/timers-state.h new file mode 100644 index 0000000000..db4e60f18f --- /dev/null +++ b/softmmu/timers-state.h @@ -0,0 +1,69 @@ +/* + * 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. + */ + +#ifndef TIMERS_STATE_H +#define TIMERS_STATE_H + +/* timers state, for sharing between icount and cpu-timers */ + +typedef struct TimersState { + /* Protected by BQL. */ + int64_t cpu_ticks_prev; + int64_t cpu_ticks_offset; + + /* + * Protect fields that can be respectively read outside the + * BQL, and written from multiple threads. + */ + QemuSeqLock vm_clock_seqlock; + QemuSpin vm_clock_lock; + + int16_t cpu_ticks_enabled; + + /* Conversion factor from emulated instructions to virtual clock ticks. */ + int16_t icount_time_shift; + + /* Compensate for varying guest execution speed. */ + int64_t qemu_icount_bias; + + int64_t vm_clock_warp_start; + int64_t cpu_clock_offset; + + /* Only written by TCG thread */ + int64_t qemu_icount; + + /* for adjusting icount */ + QEMUTimer *icount_rt_timer; + QEMUTimer *icount_vm_timer; + QEMUTimer *icount_warp_timer; +} TimersState; + +extern TimersState timers_state; + +/* + * icount needs this internal from cpu-timers when adjusting the icount shift. + */ +int64_t cpu_get_clock_locked(void); + +#endif /* TIMERS_STATE_H */ diff --git a/softmmu/vl.c b/softmmu/vl.c index 22bc570df4..6a1ee531db 100644 --- a/softmmu/vl.c +++ b/softmmu/vl.c @@ -74,6 +74,7 @@ #include "hw/audio/soundhw.h" #include "audio/audio.h" #include "sysemu/cpus.h" +#include "sysemu/cpu-timers.h" #include "migration/colo.h" #include "migration/postcopy-ram.h" #include "sysemu/kvm.h" @@ -2804,7 +2805,7 @@ static void configure_accelerators(const char *progname) error_report("falling back to %s", ac->name); } - if (use_icount && !(tcg_enabled() || qtest_enabled())) { + if (icount_enabled() && !tcg_enabled()) { error_report("-icount is not allowed with hardware virtualization"); exit(1); } @@ -4254,7 +4255,8 @@ void qemu_init(int argc, char **argv, char **envp) semihosting_arg_fallback(kernel_filename, kernel_cmdline); } - cpu_ticks_init(); + /* initialize cpu timers and VCPU throttle modules */ + cpu_timers_init(); if (default_net) { QemuOptsList *net = qemu_find_opts("net"); diff --git a/stubs/clock-warp.c b/stubs/clock-warp.c deleted file mode 100644 index b53e5dd94c..0000000000 --- a/stubs/clock-warp.c +++ /dev/null @@ -1,7 +0,0 @@ -#include "qemu/osdep.h" -#include "qemu/timer.h" - -void qemu_start_warp_timer(void) -{ -} - diff --git a/stubs/cpu-get-clock.c b/stubs/cpu-get-clock.c index 5a92810e87..9e92404816 100644 --- a/stubs/cpu-get-clock.c +++ b/stubs/cpu-get-clock.c @@ -1,5 +1,6 @@ #include "qemu/osdep.h" -#include "qemu/timer.h" +#include "sysemu/cpu-timers.h" +#include "qemu/main-loop.h" int64_t cpu_get_clock(void) { diff --git a/stubs/cpu-get-icount.c b/stubs/cpu-get-icount.c deleted file mode 100644 index 4001613240..0000000000 --- a/stubs/cpu-get-icount.c +++ /dev/null @@ -1,16 +0,0 @@ -#include "qemu/osdep.h" -#include "qemu/timer.h" -#include "sysemu/cpus.h" -#include "qemu/main-loop.h" - -int use_icount; - -int64_t cpu_get_icount(void) -{ - abort(); -} - -int64_t cpu_get_icount_raw(void) -{ - abort(); -} diff --git a/stubs/icount.c b/stubs/icount.c new file mode 100644 index 0000000000..61e28cbaf9 --- /dev/null +++ b/stubs/icount.c @@ -0,0 +1,45 @@ +#include "qemu/osdep.h" +#include "qapi/error.h" +#include "sysemu/cpu-timers.h" + +/* icount - Instruction Counter API */ + +int use_icount; + +void cpu_update_icount(CPUState *cpu) +{ + abort(); +} +void configure_icount(QemuOpts *opts, Error **errp) +{ + /* signal error */ + error_setg(errp, "cannot configure icount, TCG support not available"); +} +int64_t cpu_get_icount_raw(void) +{ + abort(); + return 0; +} +int64_t cpu_get_icount(void) +{ + abort(); + return 0; +} +int64_t cpu_icount_to_ns(int64_t icount) +{ + abort(); + return 0; +} +int64_t qemu_icount_round(int64_t count) +{ + abort(); + return 0; +} +void qemu_start_warp_timer(void) +{ + abort(); +} +void qemu_account_warp_timer(void) +{ + abort(); +} diff --git a/stubs/meson.build b/stubs/meson.build index 5730f1d967..cbd955a7cd 100644 --- a/stubs/meson.build +++ b/stubs/meson.build @@ -3,10 +3,10 @@ stub_ss.add(files('bdrv-next-monitor-owned.c')) stub_ss.add(files('blk-commit-all.c')) stub_ss.add(files('blockdev-close-all-bdrv-states.c')) stub_ss.add(files('change-state-handler.c')) -stub_ss.add(files('clock-warp.c')) stub_ss.add(files('cmos.c')) stub_ss.add(files('cpu-get-clock.c')) -stub_ss.add(files('cpu-get-icount.c')) +stub_ss.add(files('qemu-timer-notify-cb.c')) +stub_ss.add(files('icount.c')) stub_ss.add(files('dump.c')) stub_ss.add(files('error-printf.c')) stub_ss.add(files('fdset.c')) diff --git a/stubs/qemu-timer-notify-cb.c b/stubs/qemu-timer-notify-cb.c index 054b408b1c..845e46f8e0 100644 --- a/stubs/qemu-timer-notify-cb.c +++ b/stubs/qemu-timer-notify-cb.c @@ -1,5 +1,5 @@ #include "qemu/osdep.h" -#include "sysemu/cpus.h" +#include "sysemu/cpu-timers.h" #include "qemu/main-loop.h" void qemu_timer_notify_cb(void *opaque, QEMUClockType type) diff --git a/stubs/qtest.c b/stubs/qtest.c index 891eb954fb..4666a49d7d 100644 --- a/stubs/qtest.c +++ b/stubs/qtest.c @@ -18,3 +18,8 @@ bool qtest_driver(void) { return false; } + +int64_t qtest_get_virtual_clock(void) +{ + return 0; +} diff --git a/target/alpha/translate.c b/target/alpha/translate.c index 8870284f57..36be602179 100644 --- a/target/alpha/translate.c +++ b/target/alpha/translate.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "cpu.h" #include "sysemu/cpus.h" +#include "sysemu/cpu-timers.h" #include "disas/disas.h" #include "qemu/host-utils.h" #include "exec/exec-all.h" @@ -1329,7 +1330,7 @@ static DisasJumpType gen_mfpr(DisasContext *ctx, TCGv va, int regno) case 249: /* VMTIME */ helper = gen_helper_get_vmtime; do_helper: - if (use_icount) { + if (icount_enabled()) { gen_io_start(); helper(va); return DISAS_PC_STALE; diff --git a/target/arm/helper.c b/target/arm/helper.c index b394db394a..b0bc4aa534 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -24,6 +24,7 @@ #include "hw/irq.h" #include "hw/semihosting/semihost.h" #include "sysemu/cpus.h" +#include "sysemu/cpu-timers.h" #include "sysemu/kvm.h" #include "sysemu/tcg.h" #include "qemu/range.h" @@ -1206,7 +1207,7 @@ static int64_t cycles_ns_per(uint64_t cycles) static bool instructions_supported(CPUARMState *env) { - return use_icount == 1 /* Precise instruction counting */; + return icount_enabled() == 1; /* Precise instruction counting */ } static uint64_t instructions_get_count(CPUARMState *env) diff --git a/target/riscv/csr.c b/target/riscv/csr.c index 26ae347b4a..e51ed7b9ca 100644 --- a/target/riscv/csr.c +++ b/target/riscv/csr.c @@ -299,7 +299,7 @@ static int write_vstart(CPURISCVState *env, int csrno, target_ulong val) static int read_instret(CPURISCVState *env, int csrno, target_ulong *val) { #if !defined(CONFIG_USER_ONLY) - if (use_icount) { + if (icount_enabled()) { *val = cpu_get_icount(); } else { *val = cpu_get_host_ticks(); @@ -314,7 +314,7 @@ static int read_instret(CPURISCVState *env, int csrno, target_ulong *val) static int read_instreth(CPURISCVState *env, int csrno, target_ulong *val) { #if !defined(CONFIG_USER_ONLY) - if (use_icount) { + if (icount_enabled()) { *val = cpu_get_icount() >> 32; } else { *val = cpu_get_host_ticks() >> 32; diff --git a/tests/ptimer-test-stubs.c b/tests/ptimer-test-stubs.c index ed393d9082..e935a1395e 100644 --- a/tests/ptimer-test-stubs.c +++ b/tests/ptimer-test-stubs.c @@ -12,6 +12,7 @@ #include "qemu/main-loop.h" #include "sysemu/replay.h" #include "migration/vmstate.h" +#include "sysemu/cpu-timers.h" #include "ptimer-test.h" @@ -30,8 +31,8 @@ QEMUTimerListGroup main_loop_tlg; int64_t ptimer_test_time_ns; -/* Do not artificially limit period - see hw/core/ptimer.c. */ -int use_icount = 1; +/* under qtest_enabled(), will not artificially limit period - see hw/core/ptimer.c. */ +int use_icount; bool qtest_allowed; void timer_init_full(QEMUTimer *ts, diff --git a/tests/test-timed-average.c b/tests/test-timed-average.c index e2bcf5fe13..82c92500df 100644 --- a/tests/test-timed-average.c +++ b/tests/test-timed-average.c @@ -11,7 +11,7 @@ */ #include "qemu/osdep.h" - +#include "sysemu/cpu-timers.h" #include "qemu/timed-average.h" /* This is the clock for QEMU_CLOCK_VIRTUAL */ diff --git a/util/main-loop.c b/util/main-loop.c index 217c8d6056..0c5fe0107e 100644 --- a/util/main-loop.c +++ b/util/main-loop.c @@ -27,7 +27,7 @@ #include "qemu/cutils.h" #include "qemu/timer.h" #include "sysemu/qtest.h" -#include "sysemu/cpus.h" +#include "sysemu/cpu-timers.h" #include "sysemu/replay.h" #include "qemu/main-loop.h" #include "block/aio.h" @@ -521,9 +521,13 @@ void main_loop_wait(int nonblocking) mlpoll.state = ret < 0 ? MAIN_LOOP_POLL_ERR : MAIN_LOOP_POLL_OK; notifier_list_notify(&main_loop_poll_notifiers, &mlpoll); - /* CPU thread can infinitely wait for event after - missing the warp */ - qemu_start_warp_timer(); + if (icount_enabled()) { + /* + * CPU thread can infinitely wait for event after + * missing the warp + */ + qemu_start_warp_timer(); + } qemu_clock_run_all_timers(); } diff --git a/util/qemu-timer.c b/util/qemu-timer.c index ca677836cb..0674046b09 100644 --- a/util/qemu-timer.c +++ b/util/qemu-timer.c @@ -26,8 +26,10 @@ #include "qemu/main-loop.h" #include "qemu/timer.h" #include "qemu/lockable.h" +#include "sysemu/cpu-timers.h" #include "sysemu/replay.h" #include "sysemu/cpus.h" +#include "sysemu/qtest.h" #ifdef CONFIG_POSIX #include <pthread.h> @@ -134,7 +136,7 @@ static void qemu_clock_init(QEMUClockType type, QEMUTimerListNotifyCB *notify_cb bool qemu_clock_use_for_deadline(QEMUClockType type) { - return !(use_icount && (type == QEMU_CLOCK_VIRTUAL)); + return !(icount_enabled() && (type == QEMU_CLOCK_VIRTUAL)); } void qemu_clock_notify(QEMUClockType type) @@ -416,7 +418,7 @@ static bool timer_mod_ns_locked(QEMUTimerList *timer_list, static void timerlist_rearm(QEMUTimerList *timer_list) { /* Interrupt execution to force deadline recalculation. */ - if (timer_list->clock->type == QEMU_CLOCK_VIRTUAL) { + if (icount_enabled() && timer_list->clock->type == QEMU_CLOCK_VIRTUAL) { qemu_start_warp_timer(); } timerlist_notify(timer_list); @@ -633,8 +635,10 @@ int64_t qemu_clock_get_ns(QEMUClockType type) return get_clock(); default: case QEMU_CLOCK_VIRTUAL: - if (use_icount) { + if (icount_enabled()) { return cpu_get_icount(); + } else if (qtest_enabled()) { /* for qtest_clock_warp */ + return qtest_get_virtual_clock(); } else { return cpu_get_clock(); } |