[PULL 17/29] plugins: fix order of init/idle/resume callback

Alex Bennée posted 29 patches 9 months ago
Maintainers: Richard Henderson <richard.henderson@linaro.org>, Paolo Bonzini <pbonzini@redhat.com>, "Alex Bennée" <alex.bennee@linaro.org>, Alexandre Iooss <erdnaxe@crans.org>, Mahmoud Mandour <ma.mandourr@gmail.com>, Pierrick Bouvier <pierrick.bouvier@linaro.org>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Eduardo Habkost <eduardo@habkost.net>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Yanan Wang <wangyanan55@huawei.com>, Laurent Vivier <laurent@vivier.eu>, John Snow <jsnow@redhat.com>, Cleber Rosa <crosa@redhat.com>, Peter Maydell <peter.maydell@linaro.org>, Michael Rolnik <mrolnik@gmail.com>, Brian Cain <bcain@quicinc.com>, Song Gao <gaosong@loongson.cn>, "Edgar E. Iglesias" <edgar.iglesias@gmail.com>, Nicholas Piggin <npiggin@gmail.com>, Daniel Henrique Barboza <danielhb413@gmail.com>, "Cédric Le Goater" <clg@kaod.org>, Palmer Dabbelt <palmer@dabbelt.com>, Alistair Francis <alistair.francis@wdc.com>, Bin Meng <bin.meng@windriver.com>, Weiwei Li <liwei1518@gmail.com>, Liu Zhiwei <zhiwei_liu@linux.alibaba.com>, Yoshinori Sato <ysato@users.sourceforge.jp>, David Hildenbrand <david@redhat.com>, Ilya Leoshkevich <iii@linux.ibm.com>, Thomas Huth <thuth@redhat.com>, Wainer dos Santos Moschetta <wainersm@redhat.com>, Beraldo Leal <bleal@redhat.com>, Warner Losh <imp@bsdimp.com>, Kyle Evans <kevans@freebsd.org>
There is a newer version of this series
[PULL 17/29] plugins: fix order of init/idle/resume callback
Posted by Alex Bennée 9 months ago
From: Pierrick Bouvier <pierrick.bouvier@linaro.org>

We found that vcpu_init_hook was called *after* idle callback.
vcpu_init is called from cpu_realize_fn, while idle/resume cb are called
from qemu_wait_io_event (in vcpu thread).

This change ensures we only call idle and resume cb only once a plugin
was init for a given vcpu.

Next change in the series will run vcpu_init asynchronously, which will
make it run *after* resume callback as well. So we fix this now.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Message-Id: <20240213094009.150349-4-pierrick.bouvier@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240227144335.1196131-18-alex.bennee@linaro.org>

diff --git a/plugins/core.c b/plugins/core.c
index caa66311351..2392bbb8889 100644
--- a/plugins/core.c
+++ b/plugins/core.c
@@ -391,12 +391,17 @@ void qemu_plugin_vcpu_syscall_ret(CPUState *cpu, int64_t num, int64_t ret)
 
 void qemu_plugin_vcpu_idle_cb(CPUState *cpu)
 {
-    plugin_vcpu_cb__simple(cpu, QEMU_PLUGIN_EV_VCPU_IDLE);
+    /* idle and resume cb may be called before init, ignore in this case */
+    if (cpu->cpu_index < plugin.num_vcpus) {
+        plugin_vcpu_cb__simple(cpu, QEMU_PLUGIN_EV_VCPU_IDLE);
+    }
 }
 
 void qemu_plugin_vcpu_resume_cb(CPUState *cpu)
 {
-    plugin_vcpu_cb__simple(cpu, QEMU_PLUGIN_EV_VCPU_RESUME);
+    if (cpu->cpu_index < plugin.num_vcpus) {
+        plugin_vcpu_cb__simple(cpu, QEMU_PLUGIN_EV_VCPU_RESUME);
+    }
 }
 
 void qemu_plugin_register_vcpu_idle_cb(qemu_plugin_id_t id,
-- 
2.39.2