diff options
Diffstat (limited to 'cpus.c')
| -rw-r--r-- | cpus.c | 118 |
1 files changed, 101 insertions, 17 deletions
@@ -64,6 +64,8 @@ #endif /* CONFIG_LINUX */ static CPUState *next_cpu; +int64_t max_delay; +int64_t max_advance; bool cpu_is_stopped(CPUState *cpu) { @@ -102,17 +104,12 @@ static bool all_cpu_threads_idle(void) /* Protected by TimersState seqlock */ -/* Compensate for varying guest execution speed. */ -static int64_t qemu_icount_bias; -static int64_t vm_clock_warp_start; +static int64_t vm_clock_warp_start = -1; /* Conversion factor from emulated instructions to virtual clock ticks. */ static int icount_time_shift; /* Arbitrarily pick 1MIPS as the minimum allowable speed. */ #define MAX_ICOUNT_SHIFT 10 -/* Only written by TCG thread */ -static int64_t qemu_icount; - static QEMUTimer *icount_rt_timer; static QEMUTimer *icount_vm_timer; static QEMUTimer *icount_warp_timer; @@ -129,6 +126,11 @@ typedef struct TimersState { int64_t cpu_clock_offset; int32_t cpu_ticks_enabled; int64_t dummy; + + /* Compensate for varying guest execution speed. */ + int64_t qemu_icount_bias; + /* Only written by TCG thread */ + int64_t qemu_icount; } TimersState; static TimersState timers_state; @@ -139,14 +141,14 @@ static int64_t cpu_get_icount_locked(void) int64_t icount; CPUState *cpu = current_cpu; - icount = qemu_icount; + icount = timers_state.qemu_icount; if (cpu) { if (!cpu_can_do_io(cpu)) { fprintf(stderr, "Bad clock read\n"); } icount -= (cpu->icount_decr.u16.low + cpu->icount_extra); } - return qemu_icount_bias + (icount << icount_time_shift); + return timers_state.qemu_icount_bias + cpu_icount_to_ns(icount); } int64_t cpu_get_icount(void) @@ -162,6 +164,11 @@ int64_t cpu_get_icount(void) return icount; } +int64_t cpu_icount_to_ns(int64_t icount) +{ + return icount << icount_time_shift; +} + /* return the host CPU cycle counter and handle stop/restart */ /* Caller must hold the BQL */ int64_t cpu_get_ticks(void) @@ -214,6 +221,23 @@ int64_t cpu_get_clock(void) return ti; } +/* return the offset between the host clock and virtual CPU clock */ +int64_t cpu_get_clock_offset(void) +{ + int64_t ti; + unsigned start; + + do { + start = seqlock_read_begin(&timers_state.vm_clock_seqlock); + ti = timers_state.cpu_clock_offset; + if (!timers_state.cpu_ticks_enabled) { + ti -= get_clock(); + } + } while (seqlock_read_retry(&timers_state.vm_clock_seqlock, start)); + + return -ti; +} + /* enable cpu_get_ticks() * Caller must hold BQL which server as mutex for vm_clock_seqlock. */ @@ -284,7 +308,8 @@ static void icount_adjust(void) icount_time_shift++; } last_delta = delta; - qemu_icount_bias = cur_icount - (qemu_icount << icount_time_shift); + timers_state.qemu_icount_bias = cur_icount + - (timers_state.qemu_icount << icount_time_shift); seqlock_write_unlock(&timers_state.vm_clock_seqlock); } @@ -333,7 +358,7 @@ static void icount_warp_rt(void *opaque) int64_t delta = cur_time - cur_icount; warp_delta = MIN(warp_delta, delta); } - qemu_icount_bias += warp_delta; + timers_state.qemu_icount_bias += warp_delta; } vm_clock_warp_start = -1; seqlock_write_unlock(&timers_state.vm_clock_seqlock); @@ -351,7 +376,7 @@ void qtest_clock_warp(int64_t dest) int64_t deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL); int64_t warp = qemu_soonest_timeout(dest - clock, deadline); seqlock_write_lock(&timers_state.vm_clock_seqlock); - qemu_icount_bias += warp; + timers_state.qemu_icount_bias += warp; seqlock_write_unlock(&timers_state.vm_clock_seqlock); qemu_clock_run_timers(QEMU_CLOCK_VIRTUAL); @@ -428,6 +453,25 @@ void qemu_clock_warp(QEMUClockType type) } } +static bool icount_state_needed(void *opaque) +{ + return use_icount; +} + +/* + * This is a subsection for icount migration. + */ +static const VMStateDescription icount_vmstate_timers = { + .name = "timer/icount", + .version_id = 1, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_INT64(qemu_icount_bias, TimersState), + VMSTATE_INT64(qemu_icount, TimersState), + VMSTATE_END_OF_LIST() + } +}; + static const VMStateDescription vmstate_timers = { .name = "timer", .version_id = 2, @@ -437,23 +481,44 @@ static const VMStateDescription vmstate_timers = { VMSTATE_INT64(dummy, TimersState), VMSTATE_INT64_V(cpu_clock_offset, TimersState, 2), VMSTATE_END_OF_LIST() + }, + .subsections = (VMStateSubsection[]) { + { + .vmsd = &icount_vmstate_timers, + .needed = icount_state_needed, + }, { + /* empty */ + } } }; -void configure_icount(const char *option) +void configure_icount(QemuOpts *opts, Error **errp) { + const char *option; + char *rem_str = NULL; + seqlock_init(&timers_state.vm_clock_seqlock, NULL); vmstate_register(NULL, 0, &vmstate_timers, &timers_state); + option = qemu_opt_get(opts, "shift"); if (!option) { + if (qemu_opt_get(opts, "align") != NULL) { + error_setg(errp, "Please specify shift option when using align"); + } return; } - + icount_align_option = qemu_opt_get_bool(opts, "align", false); icount_warp_timer = timer_new_ns(QEMU_CLOCK_REALTIME, icount_warp_rt, NULL); if (strcmp(option, "auto") != 0) { - icount_time_shift = strtol(option, NULL, 0); + errno = 0; + icount_time_shift = strtol(option, &rem_str, 0); + if (errno != 0 || *rem_str != '\0' || !strlen(option)) { + error_setg(errp, "icount: Invalid shift value"); + } use_icount = 1; return; + } else if (icount_align_option) { + error_setg(errp, "shift=auto and align=on are incompatible"); } use_icount = 2; @@ -1250,7 +1315,8 @@ static int tcg_cpu_exec(CPUArchState *env) int64_t count; int64_t deadline; int decr; - qemu_icount -= (cpu->icount_decr.u16.low + cpu->icount_extra); + timers_state.qemu_icount -= (cpu->icount_decr.u16.low + + cpu->icount_extra); cpu->icount_decr.u16.low = 0; cpu->icount_extra = 0; deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL); @@ -1265,7 +1331,7 @@ static int tcg_cpu_exec(CPUArchState *env) } count = qemu_icount_round(deadline); - qemu_icount += count; + timers_state.qemu_icount += count; decr = (count > 0xffff) ? 0xffff : count; count -= decr; cpu->icount_decr.u16.low = decr; @@ -1278,7 +1344,8 @@ static int tcg_cpu_exec(CPUArchState *env) if (use_icount) { /* Fold pending instructions back into the instruction counter, and clear the interrupt flag. */ - qemu_icount -= (cpu->icount_decr.u16.low + cpu->icount_extra); + timers_state.qemu_icount -= (cpu->icount_decr.u16.low + + cpu->icount_extra); cpu->icount_decr.u32 = 0; cpu->icount_extra = 0; } @@ -1487,3 +1554,20 @@ void qmp_inject_nmi(Error **errp) error_set(errp, QERR_UNSUPPORTED); #endif } + +void dump_drift_info(FILE *f, fprintf_function cpu_fprintf) +{ + if (!use_icount) { + return; + } + + cpu_fprintf(f, "Host - Guest clock %"PRIi64" ms\n", + (cpu_get_clock() - cpu_get_icount())/SCALE_MS); + if (icount_align_option) { + cpu_fprintf(f, "Max guest delay %"PRIi64" ms\n", -max_delay/SCALE_MS); + cpu_fprintf(f, "Max guest advance %"PRIi64" ms\n", max_advance/SCALE_MS); + } else { + cpu_fprintf(f, "Max guest delay NA\n"); + cpu_fprintf(f, "Max guest advance NA\n"); + } +} |