Right now, cpu_exit() is not usable from all accelerators because it
includes a TCG-specific thread kick. In fact, cpu_exit() doubles as
the TCG thread-kick via tcg_kick_vcpu_thread().
In preparation for changing that, inline cpu_exit() into
tcg_kick_vcpu_thread(). The direction of the calls can then be
reversed, with an accelerator-independent cpu_exit() calling into
qemu_vcpu_kick() rather than the opposite.
Reviewed-by: Igor Mammedov <imamm...@redhat.com>
Reviewed-by: Richard Henderson <richard.hender...@linaro.org>
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
accel/tcg/cpu-exec.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index 9241bcadb5f..3ae545e888f 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -751,7 +751,16 @@ static inline bool cpu_handle_exception(CPUState *cpu, int
*ret)
void tcg_kick_vcpu_thread(CPUState *cpu)
{
- cpu_exit(cpu);
+ /*
+ * Ensure cpu_exec will see the reason why the exit request was set.
+ * FIXME: this is not always needed. Other accelerators instead
+ * read interrupt_request and set exit_request on demand from the
+ * CPU thread; see kvm_arch_pre_run() for example.
+ */
+ qatomic_store_release(&cpu->exit_request, true);
+
+ /* Ensure cpu_exec will see the exit request after TCG has exited. */
+ qatomic_store_release(&cpu->neg.icount_decr.u16.high, -1);
}
static inline bool icount_exit_request(CPUState *cpu)
@@ -780,7 +789,8 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
/* Clear the interrupt flag now since we're processing
* cpu->interrupt_request and cpu->exit_request.
* Ensure zeroing happens before reading cpu->exit_request or
- * cpu->interrupt_request (see also smp_wmb in cpu_exit())
+ * cpu->interrupt_request (see also store-release in
+ * tcg_kick_vcpu_thread())
*/
qatomic_set_mb(&cpu->neg.icount_decr.u16.high, 0);
--
2.51.0
