[v4,03/18] plugins: fix order of init/idle/resume callback

Commit Message

Pierrick Bouvier Feb. 13, 2024, 9:39 a.m. UTC

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 <[e-mail]>
Signed-off-by: Pierrick Bouvier <[e-mail]>
---
 plugins/core.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

Patch

diff --git a/plugins/core.c b/plugins/core.c
index 9e64820ad02..609d9d5c184 100644
--- a/plugins/core.c
+++ b/plugins/core.c
@@ -392,12 +392,17 @@  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,