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author | Alex Bennée <alex.bennee@linaro.org> | 2017-03-29 16:46:59 +0100 |
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committer | Alex Bennée <alex.bennee@linaro.org> | 2017-04-10 10:23:33 +0100 |
commit | 05248382251a58a14da60a640d29f570524174d3 (patch) | |
tree | 598d5843875bd5db0572094293f955bab9ef148d /cpus.c | |
parent | 243c5f77f6734776a45d50612b0f3ca2f2f6448e (diff) | |
download | qemu-05248382251a58a14da60a640d29f570524174d3.zip qemu-05248382251a58a14da60a640d29f570524174d3.tar.gz qemu-05248382251a58a14da60a640d29f570524174d3.tar.bz2 |
cpus: move icount preparation out of tcg_exec_cpu
As icount is only supported for single-threaded execution due to the
requirement for determinism let's remove it from the common
tcg_exec_cpu path.
Also remove the additional fiddling which shouldn't be required as the
icount counters should all be rectified as you enter the loop.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Diffstat (limited to 'cpus.c')
-rw-r--r-- | cpus.c | 67 |
1 files changed, 45 insertions, 22 deletions
@@ -1179,47 +1179,64 @@ static void handle_icount_deadline(void) } } -static int tcg_cpu_exec(CPUState *cpu) +static void prepare_icount_for_run(CPUState *cpu) { - int ret; -#ifdef CONFIG_PROFILER - int64_t ti; -#endif - -#ifdef CONFIG_PROFILER - ti = profile_getclock(); -#endif if (use_icount) { int64_t count; int decr; - timers_state.qemu_icount -= (cpu->icount_decr.u16.low - + cpu->icount_extra); - cpu->icount_decr.u16.low = 0; - cpu->icount_extra = 0; + + /* These should always be cleared by process_icount_data after + * each vCPU execution. However u16.high can be raised + * asynchronously by cpu_exit/cpu_interrupt/tcg_handle_interrupt + */ + g_assert(cpu->icount_decr.u16.low == 0); + g_assert(cpu->icount_extra == 0); + + count = tcg_get_icount_limit(); + timers_state.qemu_icount += count; decr = (count > 0xffff) ? 0xffff : count; count -= decr; cpu->icount_decr.u16.low = decr; cpu->icount_extra = count; } - qemu_mutex_unlock_iothread(); - cpu_exec_start(cpu); - ret = cpu_exec(cpu); - cpu_exec_end(cpu); - qemu_mutex_lock_iothread(); -#ifdef CONFIG_PROFILER - tcg_time += profile_getclock() - ti; -#endif +} + +static void process_icount_data(CPUState *cpu) +{ if (use_icount) { /* Fold pending instructions back into the instruction counter, and clear the interrupt flag. */ timers_state.qemu_icount -= (cpu->icount_decr.u16.low + cpu->icount_extra); - cpu->icount_decr.u32 = 0; + + /* Reset the counters */ + cpu->icount_decr.u16.low = 0; cpu->icount_extra = 0; replay_account_executed_instructions(); } +} + + +static int tcg_cpu_exec(CPUState *cpu) +{ + int ret; +#ifdef CONFIG_PROFILER + int64_t ti; +#endif + +#ifdef CONFIG_PROFILER + ti = profile_getclock(); +#endif + qemu_mutex_unlock_iothread(); + cpu_exec_start(cpu); + ret = cpu_exec(cpu); + cpu_exec_end(cpu); + qemu_mutex_lock_iothread(); +#ifdef CONFIG_PROFILER + tcg_time += profile_getclock() - ti; +#endif return ret; } @@ -1306,7 +1323,13 @@ static void *qemu_tcg_rr_cpu_thread_fn(void *arg) if (cpu_can_run(cpu)) { int r; + + prepare_icount_for_run(cpu); + r = tcg_cpu_exec(cpu); + + process_icount_data(cpu); + if (r == EXCP_DEBUG) { cpu_handle_guest_debug(cpu); break; |