From 013aabdc665e4256b38d8875a1a7b5e030ba98f1 Mon Sep 17 00:00:00 2001 From: Clement Deschamps Date: Sun, 21 Oct 2018 16:21:03 +0200 Subject: [PATCH] icount: fix deadlock when all cpus are sleeping 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. Signed-off-by: Clement Deschamps Message-Id: <20181021142103.19014-1-clement.deschamps@greensocs.com> Signed-off-by: Paolo Bonzini --- cpus.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/cpus.c b/cpus.c index 3978f63d8f..a2b33ccb29 100644 --- a/cpus.c +++ b/cpus.c @@ -1554,6 +1554,14 @@ static void *qemu_tcg_rr_cpu_thread_fn(void *arg) atomic_mb_set(&cpu->exit_request, 0); } + if (use_icount && 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. + */ + qemu_notify_event(); + } + qemu_tcg_rr_wait_io_event(cpu ? cpu : first_cpu); deal_with_unplugged_cpus(); }