use qemu_cpu_kick instead of cpu_exit or qemu_cpu_kick_thread

Use the same API to trigger interruption of a CPU, no matter if
under TCG or KVM.  There is no difference: these calls come from
the CPU thread, so the qemu_cpu_kick calls will send a signal
to the running thread and it will be processed synchronously,
just like a call to cpu_exit.  The only difference is in the
overhead, but neither call to cpu_exit (now qemu_cpu_kick)
is in a hot path.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2015-08-18 06:52:09 -07:00
parent aed807c8e2
commit 9102dedaa1
3 changed files with 10 additions and 11 deletions

17
cpus.c
View File

@ -1090,6 +1090,12 @@ static void qemu_cpu_kick_thread(CPUState *cpu)
#ifndef _WIN32
int err;
if (!tcg_enabled()) {
if (cpu->thread_kicked) {
return;
}
cpu->thread_kicked = true;
}
err = pthread_kill(cpu->thread->thread, SIG_IPI);
if (err) {
fprintf(stderr, "qemu:%s: %s", __func__, strerror(err));
@ -1127,21 +1133,14 @@ static void qemu_cpu_kick_thread(CPUState *cpu)
void qemu_cpu_kick(CPUState *cpu)
{
qemu_cond_broadcast(cpu->halt_cond);
if (!tcg_enabled() && !cpu->thread_kicked) {
qemu_cpu_kick_thread(cpu);
cpu->thread_kicked = true;
}
qemu_cpu_kick_thread(cpu);
}
void qemu_cpu_kick_self(void)
{
#ifndef _WIN32
assert(current_cpu);
if (!current_cpu->thread_kicked) {
qemu_cpu_kick_thread(current_cpu);
current_cpu->thread_kicked = true;
}
qemu_cpu_kick_thread(current_cpu);
#else
abort();
#endif

View File

@ -1362,7 +1362,7 @@ void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...)
is still in the running state, which can cause packets to be dropped
and state transition 'T' packets to be sent while the syscall is still
being processed. */
cpu_exit(s->c_cpu);
qemu_cpu_kick(s->c_cpu);
#endif
}

View File

@ -214,7 +214,7 @@ static void rtas_stop_self(PowerPCCPU *cpu, sPAPRMachineState *spapr,
CPUPPCState *env = &cpu->env;
cs->halted = 1;
cpu_exit(cs);
qemu_cpu_kick(cs);
/*
* While stopping a CPU, the guest calls H_CPPR which
* effectively disables interrupts on XICS level.