QEMU running with options "-icount,sleep=off -rtc clock=vm" doesn't
execute emulation at maximum possible speed.
Target virtual clock may run faster or slower than realtime clock by N
times, where N value depends on various unrelated conditions (i.e. random
from the user point of view), or possibly the target hangs completely.
Bisection shows commit 281b2201e4 ("icount: remove obsolete warp call",
2016-03-15) to be the culprit, revert it.
Suggested-by: Artem Pisarenko <artem.k.pisare...@gmail.com>
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
cpus.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/cpus.c b/cpus.c
index 361678e459..2872e7e37c 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1224,6 +1224,10 @@ static void qemu_tcg_rr_wait_io_event(CPUState *cpu)
{
while (all_cpu_threads_idle()) {
stop_tcg_kick_timer();
+
+ /* Start accounting real time to the virtual clock if the CPUs
+ are idle. */
+ qemu_clock_warp(QEMU_CLOCK_VIRTUAL);
qemu_cond_wait(cpu->halt_cond, &qemu_global_mutex);
}
--
2.17.1
