[Qemu-devel] [PATCH v5 30/73] cpu-exec: convert to cpu_halted

[Emilio G. Cota]

Reviewed-by: Richard Henderson <richard.hender...@linaro.org>
Signed-off-by: Emilio G. Cota <c...@braap.org>
---
 accel/tcg/cpu-exec.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index 870027d435..b4f46134d3 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -422,14 +422,21 @@ static inline TranslationBlock *tb_find(CPUState *cpu,
     return tb;
 }
 
-static inline bool cpu_handle_halt(CPUState *cpu)
+static inline bool cpu_handle_halt_locked(CPUState *cpu)
 {
-    if (cpu->halted) {
+    g_assert(cpu_mutex_locked(cpu));
+
+    if (cpu_halted(cpu)) {
 #if defined(TARGET_I386) && !defined(CONFIG_USER_ONLY)
         if ((cpu->interrupt_request & CPU_INTERRUPT_POLL)
             && replay_interrupt()) {
             X86CPU *x86_cpu = X86_CPU(cpu);
+
+            /* prevent deadlock; cpu_mutex must be acquired _after_ the BQL */
+            cpu_mutex_unlock(cpu);
             qemu_mutex_lock_iothread();
+            cpu_mutex_lock(cpu);
+
             apic_poll_irq(x86_cpu->apic_state);
             cpu_reset_interrupt(cpu, CPU_INTERRUPT_POLL);
             qemu_mutex_unlock_iothread();
@@ -439,12 +446,22 @@ static inline bool cpu_handle_halt(CPUState *cpu)
             return true;
         }
 
-        cpu->halted = 0;
+        cpu_halted_set(cpu, 0);
     }
 
     return false;
 }
 
+static inline bool cpu_handle_halt(CPUState *cpu)
+{
+    bool ret;
+
+    cpu_mutex_lock(cpu);
+    ret = cpu_handle_halt_locked(cpu);
+    cpu_mutex_unlock(cpu);
+    return ret;
+}
+
 static inline void cpu_handle_debug_exception(CPUState *cpu)
 {
     CPUClass *cc = CPU_GET_CLASS(cpu);
@@ -543,7 +560,7 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
         } else if (interrupt_request & CPU_INTERRUPT_HALT) {
             replay_interrupt();
             cpu->interrupt_request &= ~CPU_INTERRUPT_HALT;
-            cpu->halted = 1;
+            cpu_halted_set(cpu, 1);
             cpu->exception_index = EXCP_HLT;
             qemu_mutex_unlock_iothread();
             return true;
-- 
2.17.1