Implement signal handling for MSHV vCPUs to support asynchronous
interrupts from the main thread.
Signed-off-by: Magnus Kulke <magnusku...@linux.microsoft.com>
---
accel/mshv/mshv-all.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/accel/mshv/mshv-all.c b/accel/mshv/mshv-all.c
index 71fedc9137..97212c54f1 100644
--- a/accel/mshv/mshv-all.c
+++ b/accel/mshv/mshv-all.c
@@ -531,6 +531,33 @@ static int mshv_cpu_exec(CPUState *cpu)
return ret;
}
+/*
+ * The signal handler is triggered when QEMU's main thread receives a SIG_IPI
+ * (SIGUSR1). This signal causes the current CPU thread to be kicked, forcing a
+ * VM exit on the CPU. The VM exit generates an exit reason that breaks the
loop
+ * (see mshv_cpu_exec). If the exit is due to a Ctrl+A+x command, the system
+ * will shut down. For other cases, the system will continue running.
+ */
+static void sa_ipi_handler(int sig)
+{
+ qemu_cpu_kick_self();
+}
+
+static void init_signal(CPUState *cpu)
+{
+ /* init cpu signals */
+ struct sigaction sigact;
+ sigset_t set;
+
+ memset(&sigact, 0, sizeof(sigact));
+ sigact.sa_handler = sa_ipi_handler;
+ sigaction(SIG_IPI, &sigact, NULL);
+
+ pthread_sigmask(SIG_BLOCK, NULL, &set);
+ sigdelset(&set, SIG_IPI);
+ pthread_sigmask(SIG_SETMASK, &set, NULL);
+}
+
static void *mshv_vcpu_thread(void *arg)
{
CPUState *cpu = arg;
@@ -547,6 +574,7 @@ static void *mshv_vcpu_thread(void *arg)
error_report("Failed to init vcpu %d", cpu->cpu_index);
goto cleanup;
}
+ init_signal(cpu);
/* signal CPU creation */
cpu_thread_signal_created(cpu);
--
2.34.1
