system/cpus: rename qemu_mutex_lock_iothread() to bql_lock()

The Big QEMU Lock (BQL) has many names and they are confusing. The actual QemuMutex variable is called qemu_global_mutex but it's commonly referred to as the BQL in discussions and some code comments. The locking APIs, however, are called qemu_mutex_lock_iothread() and qemu_mutex_unlock_iothread(). The "iothread" name is historic and comes from when the main thread was split into into KVM vcpu threads and the "iothread" (now called the main loop thread). I have contributed to the confusion myself by introducing a separate --object iothread, a separate concept unrelated to the BQL. The "iothread" name is no longer appropriate for the BQL. Rename the locking APIs to: - void bql_lock(void) - void bql_unlock(void) - bool bql_locked(void) There are more APIs with "iothread" in their names. Subsequent patches will rename them. There are also comments and documentation that will be updated in later patches. Signed-off-by: Stefan Hajnoczi <[email protected]> Reviewed-by: Paul Durrant <[email protected]> Acked-by: Fabiano Rosas <[email protected]> Acked-by: David Woodhouse <[email protected]> Reviewed-by: Cédric Le Goater <[email protected]> Acked-by: Peter Xu <[email protected]> Acked-by: Eric Farman <[email protected]> Reviewed-by: Harsh Prateek Bora <[email protected]> Acked-by: Hyman Huang <[email protected]> Reviewed-by: Akihiko Odaki <[email protected]> Message-id: [email protected] Signed-off-by: Stefan Hajnoczi <[email protected]>
espressif · Jan 8, 2024 · 195801d · 195801d
1 parent 897a06c
commit 195801d
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Showing 95 changed files with 529 additions and 529 deletions.
diff --git a/accel/accel-blocker.c b/accel/accel-blocker.c
@@ -41,7 +41,7 @@ void accel_blocker_init(void)
 
 void accel_ioctl_begin(void)
 {
-    if (likely(qemu_mutex_iothread_locked())) {
+    if (likely(bql_locked())) {
         return;
     }
 
@@ -51,7 +51,7 @@ void accel_ioctl_begin(void)
 
 void accel_ioctl_end(void)
 {
-    if (likely(qemu_mutex_iothread_locked())) {
+    if (likely(bql_locked())) {
         return;
     }
 
@@ -62,7 +62,7 @@ void accel_ioctl_end(void)
 
 void accel_cpu_ioctl_begin(CPUState *cpu)
 {
-    if (unlikely(qemu_mutex_iothread_locked())) {
+    if (unlikely(bql_locked())) {
         return;
     }
 
@@ -72,7 +72,7 @@ void accel_cpu_ioctl_begin(CPUState *cpu)
 
 void accel_cpu_ioctl_end(CPUState *cpu)
 {
-    if (unlikely(qemu_mutex_iothread_locked())) {
+    if (unlikely(bql_locked())) {
         return;
     }
 
@@ -105,7 +105,7 @@ void accel_ioctl_inhibit_begin(void)
      * We allow to inhibit only when holding the BQL, so we can identify
      * when an inhibitor wants to issue an ioctl easily.
      */
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
 
     /* Block further invocations of the ioctls outside the BQL.  */
     CPU_FOREACH(cpu) {

diff --git a/accel/dummy-cpus.c b/accel/dummy-cpus.c
@@ -24,7 +24,7 @@ static void *dummy_cpu_thread_fn(void *arg)
 
     rcu_register_thread();
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     qemu_thread_get_self(cpu->thread);
     cpu->thread_id = qemu_get_thread_id();
     cpu->neg.can_do_io = true;
@@ -43,7 +43,7 @@ static void *dummy_cpu_thread_fn(void *arg)
     qemu_guest_random_seed_thread_part2(cpu->random_seed);
 
     do {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
 #ifndef _WIN32
         do {
             int sig;
@@ -56,11 +56,11 @@ static void *dummy_cpu_thread_fn(void *arg)
 #else
         qemu_sem_wait(&cpu->sem);
 #endif
-        qemu_mutex_lock_iothread();
+        bql_lock();
         qemu_wait_io_event(cpu);
     } while (!cpu->unplug);
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     rcu_unregister_thread();
     return NULL;
 }

diff --git a/accel/hvf/hvf-accel-ops.c b/accel/hvf/hvf-accel-ops.c
@@ -424,7 +424,7 @@ static void *hvf_cpu_thread_fn(void *arg)
 
     rcu_register_thread();
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     qemu_thread_get_self(cpu->thread);
 
     cpu->thread_id = qemu_get_thread_id();
@@ -449,7 +449,7 @@ static void *hvf_cpu_thread_fn(void *arg)
 
     hvf_vcpu_destroy(cpu);
     cpu_thread_signal_destroyed(cpu);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     rcu_unregister_thread();
     return NULL;
 }

diff --git a/accel/kvm/kvm-accel-ops.c b/accel/kvm/kvm-accel-ops.c
@@ -33,7 +33,7 @@ static void *kvm_vcpu_thread_fn(void *arg)
 
     rcu_register_thread();
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     qemu_thread_get_self(cpu->thread);
     cpu->thread_id = qemu_get_thread_id();
     cpu->neg.can_do_io = true;
@@ -58,7 +58,7 @@ static void *kvm_vcpu_thread_fn(void *arg)
 
     kvm_destroy_vcpu(cpu);
     cpu_thread_signal_destroyed(cpu);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     rcu_unregister_thread();
     return NULL;
 }

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
@@ -806,7 +806,7 @@ static void kvm_dirty_ring_flush(void)
      * should always be with BQL held, serialization is guaranteed.
      * However, let's be sure of it.
      */
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
     /*
      * First make sure to flush the hardware buffers by kicking all
      * vcpus out in a synchronous way.
@@ -1391,9 +1391,9 @@ static void *kvm_dirty_ring_reaper_thread(void *data)
         trace_kvm_dirty_ring_reaper("wakeup");
         r->reaper_state = KVM_DIRTY_RING_REAPER_REAPING;
 
-        qemu_mutex_lock_iothread();
+        bql_lock();
         kvm_dirty_ring_reap(s, NULL);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
 
         r->reaper_iteration++;
     }
@@ -2817,7 +2817,7 @@ int kvm_cpu_exec(CPUState *cpu)
         return EXCP_HLT;
     }
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     cpu_exec_start(cpu);
 
     do {
@@ -2857,11 +2857,11 @@ int kvm_cpu_exec(CPUState *cpu)
 
 #ifdef KVM_HAVE_MCE_INJECTION
         if (unlikely(have_sigbus_pending)) {
-            qemu_mutex_lock_iothread();
+            bql_lock();
             kvm_arch_on_sigbus_vcpu(cpu, pending_sigbus_code,
                                     pending_sigbus_addr);
             have_sigbus_pending = false;
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
         }
 #endif
 
@@ -2927,7 +2927,7 @@ int kvm_cpu_exec(CPUState *cpu)
              * still full.  Got kicked by KVM_RESET_DIRTY_RINGS.
              */
             trace_kvm_dirty_ring_full(cpu->cpu_index);
-            qemu_mutex_lock_iothread();
+            bql_lock();
             /*
              * We throttle vCPU by making it sleep once it exit from kernel
              * due to dirty ring full. In the dirtylimit scenario, reaping
@@ -2939,7 +2939,7 @@ int kvm_cpu_exec(CPUState *cpu)
             } else {
                 kvm_dirty_ring_reap(kvm_state, NULL);
             }
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             dirtylimit_vcpu_execute(cpu);
             ret = 0;
             break;
@@ -2956,9 +2956,9 @@ int kvm_cpu_exec(CPUState *cpu)
                 break;
             case KVM_SYSTEM_EVENT_CRASH:
                 kvm_cpu_synchronize_state(cpu);
-                qemu_mutex_lock_iothread();
+                bql_lock();
                 qemu_system_guest_panicked(cpu_get_crash_info(cpu));
-                qemu_mutex_unlock_iothread();
+                bql_unlock();
                 ret = 0;
                 break;
             default:
@@ -2973,7 +2973,7 @@ int kvm_cpu_exec(CPUState *cpu)
     } while (ret == 0);
 
     cpu_exec_end(cpu);
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     if (ret < 0) {
         cpu_dump_state(cpu, stderr, CPU_DUMP_CODE);

diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
@@ -558,8 +558,8 @@ static void cpu_exec_longjmp_cleanup(CPUState *cpu)
         tcg_ctx->gen_tb = NULL;
     }
 #endif
-    if (qemu_mutex_iothread_locked()) {
-        qemu_mutex_unlock_iothread();
+    if (bql_locked()) {
+        bql_unlock();
     }
     assert_no_pages_locked();
 }
@@ -680,10 +680,10 @@ static inline bool cpu_handle_halt(CPUState *cpu)
 #if defined(TARGET_I386)
         if (cpu->interrupt_request & CPU_INTERRUPT_POLL) {
             X86CPU *x86_cpu = X86_CPU(cpu);
-            qemu_mutex_lock_iothread();
+            bql_lock();
             apic_poll_irq(x86_cpu->apic_state);
             cpu_reset_interrupt(cpu, CPU_INTERRUPT_POLL);
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
         }
 #endif /* TARGET_I386 */
         if (!cpu_has_work(cpu)) {
@@ -749,9 +749,9 @@ static inline bool cpu_handle_exception(CPUState *cpu, int *ret)
 #else
         if (replay_exception()) {
             CPUClass *cc = CPU_GET_CLASS(cpu);
-            qemu_mutex_lock_iothread();
+            bql_lock();
             cc->tcg_ops->do_interrupt(cpu);
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             cpu->exception_index = -1;
 
             if (unlikely(cpu->singlestep_enabled)) {
@@ -812,7 +812,7 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
 
     if (unlikely(qatomic_read(&cpu->interrupt_request))) {
         int interrupt_request;
-        qemu_mutex_lock_iothread();
+        bql_lock();
         interrupt_request = cpu->interrupt_request;
         if (unlikely(cpu->singlestep_enabled & SSTEP_NOIRQ)) {
             /* Mask out external interrupts for this step. */
@@ -821,7 +821,7 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
         if (interrupt_request & CPU_INTERRUPT_DEBUG) {
             cpu->interrupt_request &= ~CPU_INTERRUPT_DEBUG;
             cpu->exception_index = EXCP_DEBUG;
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             return true;
         }
 #if !defined(CONFIG_USER_ONLY)
@@ -832,7 +832,7 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
             cpu->interrupt_request &= ~CPU_INTERRUPT_HALT;
             cpu->halted = 1;
             cpu->exception_index = EXCP_HLT;
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             return true;
         }
 #if defined(TARGET_I386)
@@ -843,14 +843,14 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
             cpu_svm_check_intercept_param(env, SVM_EXIT_INIT, 0, 0);
             do_cpu_init(x86_cpu);
             cpu->exception_index = EXCP_HALTED;
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             return true;
         }
 #else
         else if (interrupt_request & CPU_INTERRUPT_RESET) {
             replay_interrupt();
             cpu_reset(cpu);
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             return true;
         }
 #endif /* !TARGET_I386 */
@@ -873,7 +873,7 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
                  */
                 if (unlikely(cpu->singlestep_enabled)) {
                     cpu->exception_index = EXCP_DEBUG;
-                    qemu_mutex_unlock_iothread();
+                    bql_unlock();
                     return true;
                 }
                 cpu->exception_index = -1;
@@ -892,7 +892,7 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
         }
 
         /* If we exit via cpu_loop_exit/longjmp it is reset in cpu_exec */
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 
     /* Finally, check if we need to exit to the main loop.  */

diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
@@ -2030,10 +2030,10 @@ static uint64_t do_ld_mmio_beN(CPUState *cpu, CPUTLBEntryFull *full,
     section = io_prepare(&mr_offset, cpu, full->xlat_section, attrs, addr, ra);
     mr = section->mr;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     ret = int_ld_mmio_beN(cpu, full, ret_be, addr, size, mmu_idx,
                           type, ra, mr, mr_offset);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     return ret;
 }
@@ -2054,12 +2054,12 @@ static Int128 do_ld16_mmio_beN(CPUState *cpu, CPUTLBEntryFull *full,
     section = io_prepare(&mr_offset, cpu, full->xlat_section, attrs, addr, ra);
     mr = section->mr;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     a = int_ld_mmio_beN(cpu, full, ret_be, addr, size - 8, mmu_idx,
                         MMU_DATA_LOAD, ra, mr, mr_offset);
     b = int_ld_mmio_beN(cpu, full, ret_be, addr + size - 8, 8, mmu_idx,
                         MMU_DATA_LOAD, ra, mr, mr_offset + size - 8);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     return int128_make128(b, a);
 }
@@ -2577,10 +2577,10 @@ static uint64_t do_st_mmio_leN(CPUState *cpu, CPUTLBEntryFull *full,
     section = io_prepare(&mr_offset, cpu, full->xlat_section, attrs, addr, ra);
     mr = section->mr;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     ret = int_st_mmio_leN(cpu, full, val_le, addr, size, mmu_idx,
                           ra, mr, mr_offset);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     return ret;
 }
@@ -2601,12 +2601,12 @@ static uint64_t do_st16_mmio_leN(CPUState *cpu, CPUTLBEntryFull *full,
     section = io_prepare(&mr_offset, cpu, full->xlat_section, attrs, addr, ra);
     mr = section->mr;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     int_st_mmio_leN(cpu, full, int128_getlo(val_le), addr, 8,
                     mmu_idx, ra, mr, mr_offset);
     ret = int_st_mmio_leN(cpu, full, int128_gethi(val_le), addr + 8,
                           size - 8, mmu_idx, ra, mr, mr_offset + 8);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     return ret;
 }

diff --git a/accel/tcg/tcg-accel-ops-icount.c b/accel/tcg/tcg-accel-ops-icount.c
@@ -126,9 +126,9 @@ void icount_prepare_for_run(CPUState *cpu, int64_t cpu_budget)
          * We're called without the iothread lock, so must take it while
          * we're calling timer handlers.
          */
-        qemu_mutex_lock_iothread();
+        bql_lock();
         icount_notify_aio_contexts();
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 }