[Qemu-devel] [PATCH qom-cpu for-next 0/2] QOM CPUState, part 12: CPU loops, revisited

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* [Qemu-devel] [PATCH qom-cpu for-next 0/2] QOM CPUState, part 12: CPU loops, revisited
@ 2013-07-30 16:55 Andreas Färber
  2013-07-30 16:55   ` [Qemu-devel] " Andreas Färber
                   ` (2 more replies)
  0 siblings, 3 replies; 13+ messages in thread
From: Andreas Färber @ 2013-07-30 16:55 UTC (permalink / raw)
  To: qemu-devel
  Cc: Eduardo Habkost, Michael S. Tsirkin, Riku Voipio,
	Markus Armbruster, Blue Swirl, Anthony Liguori, Igor Mammedov,
	Paolo Bonzini, Andreas Färber, Aurélien Jarno

Hello everyone,

A short CPUState series for a change: This mini-series replaces our home-grown
CPU list (first_cpu global and CPUState::next_cpu) with a QTAILQ.

To avoid repeated QTAILQ_FOREACH(foo, cpus, node) I am proposing a wrapper
CPU_FOREACH(foo) to hide the implementation details, as requested by mst,
while keeping inline loops, as requested by Markus.

The bulk of patch 1 is mechanical for/while loop conversions, except for:
exec.c: QTAILQ_INSERT_TAIL()
linux-user/syscall.c: QTAILQ_REMOVE() -- untested!

Having such a stable API will help with vCPU hot-unplug.

Patch 2 is controversial: It drops qemu_for_each_cpu() on Markus' request.
I'm including it as RFC to showcase what exactly those suggestions involve.
Converting from for (cpu = ...) to CPU_FOREACH(cpu) is obviously much more
straightforward than converting between function and loop, therefore with
patch 1 in mind, it seems best to still use for loops, which since recently
no longer require CPUArchState, the original trigger for qemu_for_each_cpu().

Available for testing at:
git://github.com/afaerber/qemu-cpu.git qom-cpu-12.v1
https://github.com/afaerber/qemu-cpu/commits/qom-cpu-12.v1

Regards,
Andreas

>From CPUState part 10 v1:
* Instead of replacing every loop with qemu_for_each_cpu()
  replace loops with CPU_FOREACH() macro, based on QTAILQ_FOREACH().

Cc: Markus Armbruster <armbru@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Anthony Liguori <anthony@codemonkey.ws>
Cc: Blue Swirl <blauwirbel@gmail.com>
Cc: Aurélien Jarno <aurelien@aurel32.net>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Riku Voipio <riku.voipio@iki.fi>

Andreas Färber (2):
  cpu: Use QTAILQ for CPU list
  cpu: Replace qemu_for_each_cpu()

 arch_init.c               | 11 ++++-----
 cpus.c                    | 58 ++++++++++++++++++++---------------------------
 cputlb.c                  |  2 +-
 dump.c                    | 10 ++++----
 exec.c                    | 33 ++++++++-------------------
 gdbstub.c                 | 14 ++++++------
 hw/acpi/piix4.c           | 20 ++++++++--------
 hw/arm/boot.c             |  2 +-
 hw/i386/kvm/clock.c       |  2 +-
 hw/i386/kvmvapic.c        |  2 +-
 hw/i386/pc.c              |  3 +--
 hw/ppc/e500.c             |  2 +-
 hw/ppc/ppc.c              |  2 +-
 hw/ppc/spapr.c            |  4 ++--
 include/qom/cpu.h         | 20 ++++++++--------
 kvm-all.c                 |  8 +++----
 linux-user/elfload.c      |  2 +-
 linux-user/main.c         | 10 +++++---
 linux-user/syscall.c      | 17 ++------------
 memory_mapping.c          |  5 ++--
 monitor.c                 |  2 +-
 qom/cpu.c                 | 30 ++++++++----------------
 target-i386/helper.c      |  3 +--
 target-i386/misc_helper.c |  2 +-
 target-mips/op_helper.c   | 10 ++++----
 target-ppc/excp_helper.c  |  2 +-
 translate-all.c           |  4 ++--
 27 files changed, 113 insertions(+), 167 deletions(-)

-- 
1.8.1.4

^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH qom-cpu for-next 1/2] cpu: Use QTAILQ for CPU list
  2013-07-30 16:55 [Qemu-devel] [PATCH qom-cpu for-next 0/2] QOM CPUState, part 12: CPU loops, revisited Andreas Färber
@ 2013-07-30 16:55   ` Andreas Färber
  2013-07-30 16:55 ` [Qemu-devel] [RFC qom-cpu for-next 2/2] cpu: Replace qemu_for_each_cpu() Andreas Färber
  2013-08-14 11:49 ` [Qemu-devel] [PATCH qom-cpu for-next 0/2] QOM CPUState, part 12: CPU loops, revisited Andreas Färber
  2 siblings, 0 replies; 13+ messages in thread
From: Andreas Färber @ 2013-07-30 16:55 UTC (permalink / raw)
  To: qemu-devel
  Cc: Andreas Färber, Paul Brook, Peter Maydell, Anthony Liguori,
	Alexander Graf, Scott Wood, Gleb Natapov, Paolo Bonzini,
	Riku Voipio, Luiz Capitulino, Aurelien Jarno, open list:e500,
	open list:Overall

Introduce CPU_FOREACH(), CPU_FOREACH_SAFE() and CPU_NEXT() shorthand
macros.

Signed-off-by: Andreas Färber <afaerber@suse.de>
---
 cpus.c                    | 47 ++++++++++++++++++++---------------------------
 cputlb.c                  |  2 +-
 dump.c                    | 10 +++++-----
 exec.c                    | 26 ++++++++++----------------
 gdbstub.c                 | 14 +++++++-------
 hw/arm/boot.c             |  2 +-
 hw/i386/kvm/clock.c       |  2 +-
 hw/i386/kvmvapic.c        |  2 +-
 hw/i386/pc.c              |  3 +--
 hw/ppc/e500.c             |  2 +-
 hw/ppc/ppc.c              |  2 +-
 hw/ppc/spapr.c            |  4 ++--
 include/qom/cpu.h         | 11 +++++++++--
 kvm-all.c                 |  8 ++++----
 linux-user/elfload.c      |  2 +-
 linux-user/main.c         | 10 +++++++---
 linux-user/syscall.c      | 17 ++---------------
 memory_mapping.c          |  5 +++--
 monitor.c                 |  2 +-
 target-i386/helper.c      |  3 +--
 target-i386/misc_helper.c |  2 +-
 target-mips/op_helper.c   | 10 ++++------
 target-ppc/excp_helper.c  |  2 +-
 translate-all.c           |  4 ++--
 24 files changed, 87 insertions(+), 105 deletions(-)

diff --git a/cpus.c b/cpus.c
index 0f65e76..1e2fd8a 100644
--- a/cpus.c
+++ b/cpus.c
@@ -81,7 +81,7 @@ static bool all_cpu_threads_idle(void)
 {
     CPUState *cpu;
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         if (!cpu_thread_is_idle(cpu)) {
             return false;
         }
@@ -394,7 +394,7 @@ void hw_error(const char *fmt, ...)
     fprintf(stderr, "qemu: hardware error: ");
     vfprintf(stderr, fmt, ap);
     fprintf(stderr, "\n");
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         fprintf(stderr, "CPU #%d:\n", cpu->cpu_index);
         cpu_dump_state(cpu, stderr, fprintf, CPU_DUMP_FPU);
     }
@@ -406,7 +406,7 @@ void cpu_synchronize_all_states(void)
 {
     CPUState *cpu;
 
-    for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         cpu_synchronize_state(cpu);
     }
 }
@@ -415,7 +415,7 @@ void cpu_synchronize_all_post_reset(void)
 {
     CPUState *cpu;
 
-    for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         cpu_synchronize_post_reset(cpu);
     }
 }
@@ -424,7 +424,7 @@ void cpu_synchronize_all_post_init(void)
 {
     CPUState *cpu;
 
-    for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         cpu_synchronize_post_init(cpu);
     }
 }
@@ -743,7 +743,7 @@ static void qemu_tcg_wait_io_event(void)
         qemu_cond_wait(&qemu_io_proceeded_cond, &qemu_global_mutex);
     }
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         qemu_wait_io_event_common(cpu);
     }
 }
@@ -855,11 +855,11 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
     qemu_cond_signal(&qemu_cpu_cond);
 
     /* wait for initial kick-off after machine start */
-    while (first_cpu->stopped) {
+    while (QTAILQ_FIRST(&cpus)->stopped) {
         qemu_cond_wait(tcg_halt_cond, &qemu_global_mutex);
 
         /* process any pending work */
-        for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        CPU_FOREACH(cpu) {
             qemu_wait_io_event_common(cpu);
         }
     }
@@ -969,13 +969,12 @@ void qemu_mutex_unlock_iothread(void)
 
 static int all_vcpus_paused(void)
 {
-    CPUState *cpu = first_cpu;
+    CPUState *cpu;
 
-    while (cpu) {
+    CPU_FOREACH(cpu) {
         if (!cpu->stopped) {
             return 0;
         }
-        cpu = cpu->next_cpu;
     }
 
     return 1;
@@ -983,23 +982,20 @@ static int all_vcpus_paused(void)
 
 void pause_all_vcpus(void)
 {
-    CPUState *cpu = first_cpu;
+    CPUState *cpu;
 
     qemu_clock_enable(vm_clock, false);
-    while (cpu) {
+    CPU_FOREACH(cpu) {
         cpu->stop = true;
         qemu_cpu_kick(cpu);
-        cpu = cpu->next_cpu;
     }
 
     if (qemu_in_vcpu_thread()) {
         cpu_stop_current();
         if (!kvm_enabled()) {
-            cpu = first_cpu;
-            while (cpu) {
+            CPU_FOREACH(cpu) {
                 cpu->stop = false;
                 cpu->stopped = true;
-                cpu = cpu->next_cpu;
             }
             return;
         }
@@ -1007,10 +1003,8 @@ void pause_all_vcpus(void)
 
     while (!all_vcpus_paused()) {
         qemu_cond_wait(&qemu_pause_cond, &qemu_global_mutex);
-        cpu = first_cpu;
-        while (cpu) {
+        CPU_FOREACH(cpu) {
             qemu_cpu_kick(cpu);
-            cpu = cpu->next_cpu;
         }
     }
 }
@@ -1024,12 +1018,11 @@ void cpu_resume(CPUState *cpu)
 
 void resume_all_vcpus(void)
 {
-    CPUState *cpu = first_cpu;
+    CPUState *cpu;
 
     qemu_clock_enable(vm_clock, true);
-    while (cpu) {
+    CPU_FOREACH(cpu) {
         cpu_resume(cpu);
-        cpu = cpu->next_cpu;
     }
 }
 
@@ -1181,7 +1174,7 @@ static void tcg_exec_all(void)
     if (next_cpu == NULL) {
         next_cpu = first_cpu;
     }
-    for (; next_cpu != NULL && !exit_request; next_cpu = next_cpu->next_cpu) {
+    for (; next_cpu != NULL && !exit_request; next_cpu = CPU_NEXT(next_cpu)) {
         CPUState *cpu = next_cpu;
         CPUArchState *env = cpu->env_ptr;
 
@@ -1206,7 +1199,7 @@ void set_numa_modes(void)
     CPUState *cpu;
     int i;
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         for (i = 0; i < nb_numa_nodes; i++) {
             if (test_bit(cpu->cpu_index, node_cpumask[i])) {
                 cpu->numa_node = i;
@@ -1228,7 +1221,7 @@ CpuInfoList *qmp_query_cpus(Error **errp)
     CpuInfoList *head = NULL, *cur_item = NULL;
     CPUState *cpu;
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         CpuInfoList *info;
 #if defined(TARGET_I386)
         X86CPU *x86_cpu = X86_CPU(cpu);
@@ -1357,7 +1350,7 @@ void qmp_inject_nmi(Error **errp)
 #if defined(TARGET_I386)
     CPUState *cs;
 
-    for (cs = first_cpu; cs != NULL; cs = cs->next_cpu) {
+    CPU_FOREACH(cs) {
         X86CPU *cpu = X86_CPU(cs);
         CPUX86State *env = &cpu->env;
 
diff --git a/cputlb.c b/cputlb.c
index 977c0ca..19ecf60 100644
--- a/cputlb.c
+++ b/cputlb.c
@@ -189,7 +189,7 @@ void cpu_tlb_reset_dirty_all(ram_addr_t start1, ram_addr_t length)
     CPUState *cpu;
     CPUArchState *env;
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         int mmu_idx;
 
         env = cpu->env_ptr;
diff --git a/dump.c b/dump.c
index 6a3a72a..dac97a3 100644
--- a/dump.c
+++ b/dump.c
@@ -279,7 +279,7 @@ static int write_elf64_notes(DumpState *s)
     int ret;
     int id;
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         id = cpu_index(cpu);
         ret = cpu_write_elf64_note(fd_write_vmcore, cpu, id, s);
         if (ret < 0) {
@@ -288,7 +288,7 @@ static int write_elf64_notes(DumpState *s)
         }
     }
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         ret = cpu_write_elf64_qemunote(fd_write_vmcore, cpu, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to write CPU status.\n");
@@ -329,7 +329,7 @@ static int write_elf32_notes(DumpState *s)
     int ret;
     int id;
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         id = cpu_index(cpu);
         ret = cpu_write_elf32_note(fd_write_vmcore, cpu, id, s);
         if (ret < 0) {
@@ -338,7 +338,7 @@ static int write_elf32_notes(DumpState *s)
         }
     }
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         ret = cpu_write_elf32_qemunote(fd_write_vmcore, cpu, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to write CPU status.\n");
@@ -734,7 +734,7 @@ static int dump_init(DumpState *s, int fd, bool paging, bool has_filter,
      */
     cpu_synchronize_all_states();
     nr_cpus = 0;
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         nr_cpus++;
     }
 
diff --git a/exec.c b/exec.c
index c4f2894..4ee61a6 100644
--- a/exec.c
+++ b/exec.c
@@ -69,7 +69,7 @@ static MemoryRegion io_mem_unassigned;
 
 #endif
 
-CPUState *first_cpu;
+struct CPUTailQ cpus = QTAILQ_HEAD_INITIALIZER(cpus);
 /* current CPU in the current thread. It is only valid inside
    cpu_exec() */
 DEFINE_TLS(CPUState *, current_cpu);
@@ -351,26 +351,23 @@ const VMStateDescription vmstate_cpu_common = {
 
 CPUState *qemu_get_cpu(int index)
 {
-    CPUState *cpu = first_cpu;
+    CPUState *cpu;
 
-    while (cpu) {
+    CPU_FOREACH(cpu) {
         if (cpu->cpu_index == index) {
-            break;
+            return cpu;
         }
-        cpu = cpu->next_cpu;
     }
 
-    return cpu;
+    return NULL;
 }
 
 void qemu_for_each_cpu(void (*func)(CPUState *cpu, void *data), void *data)
 {
     CPUState *cpu;
 
-    cpu = first_cpu;
-    while (cpu) {
+    CPU_FOREACH(cpu) {
         func(cpu, data);
-        cpu = cpu->next_cpu;
     }
 }
 
@@ -378,17 +375,14 @@ void cpu_exec_init(CPUArchState *env)
 {
     CPUState *cpu = ENV_GET_CPU(env);
     CPUClass *cc = CPU_GET_CLASS(cpu);
-    CPUState **pcpu;
+    CPUState *some_cpu;
     int cpu_index;
 
 #if defined(CONFIG_USER_ONLY)
     cpu_list_lock();
 #endif
-    cpu->next_cpu = NULL;
-    pcpu = &first_cpu;
     cpu_index = 0;
-    while (*pcpu != NULL) {
-        pcpu = &(*pcpu)->next_cpu;
+    CPU_FOREACH(some_cpu) {
         cpu_index++;
     }
     cpu->cpu_index = cpu_index;
@@ -398,7 +392,7 @@ void cpu_exec_init(CPUArchState *env)
 #ifndef CONFIG_USER_ONLY
     cpu->thread_id = qemu_get_thread_id();
 #endif
-    *pcpu = cpu;
+    QTAILQ_INSERT_TAIL(&cpus, cpu, node);
 #if defined(CONFIG_USER_ONLY)
     cpu_list_unlock();
 #endif
@@ -1759,7 +1753,7 @@ static void tcg_commit(MemoryListener *listener)
     /* since each CPU stores ram addresses in its TLB cache, we must
        reset the modified entries */
     /* XXX: slow ! */
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         CPUArchState *env = cpu->env_ptr;
 
         tlb_flush(env, 1);
diff --git a/gdbstub.c b/gdbstub.c
index 1af25a6..ae53df0 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -646,7 +646,7 @@ static int gdb_breakpoint_insert(target_ulong addr, target_ulong len, int type)
     switch (type) {
     case GDB_BREAKPOINT_SW:
     case GDB_BREAKPOINT_HW:
-        for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        CPU_FOREACH(cpu) {
             env = cpu->env_ptr;
             err = cpu_breakpoint_insert(env, addr, BP_GDB, NULL);
             if (err)
@@ -657,7 +657,7 @@ static int gdb_breakpoint_insert(target_ulong addr, target_ulong len, int type)
     case GDB_WATCHPOINT_WRITE:
     case GDB_WATCHPOINT_READ:
     case GDB_WATCHPOINT_ACCESS:
-        for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        CPU_FOREACH(cpu) {
             env = cpu->env_ptr;
             err = cpu_watchpoint_insert(env, addr, len, xlat_gdb_type[type],
                                         NULL);
@@ -684,7 +684,7 @@ static int gdb_breakpoint_remove(target_ulong addr, target_ulong len, int type)
     switch (type) {
     case GDB_BREAKPOINT_SW:
     case GDB_BREAKPOINT_HW:
-        for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        CPU_FOREACH(cpu) {
             env = cpu->env_ptr;
             err = cpu_breakpoint_remove(env, addr, BP_GDB);
             if (err)
@@ -695,7 +695,7 @@ static int gdb_breakpoint_remove(target_ulong addr, target_ulong len, int type)
     case GDB_WATCHPOINT_WRITE:
     case GDB_WATCHPOINT_READ:
     case GDB_WATCHPOINT_ACCESS:
-        for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        CPU_FOREACH(cpu) {
             env = cpu->env_ptr;
             err = cpu_watchpoint_remove(env, addr, len, xlat_gdb_type[type]);
             if (err)
@@ -718,7 +718,7 @@ static void gdb_breakpoint_remove_all(void)
         return;
     }
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         env = cpu->env_ptr;
         cpu_breakpoint_remove_all(env, BP_GDB);
 #ifndef CONFIG_USER_ONLY
@@ -742,7 +742,7 @@ static CPUState *find_cpu(uint32_t thread_id)
 {
     CPUState *cpu;
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         if (cpu_index(cpu) == thread_id) {
             return cpu;
         }
@@ -1068,7 +1068,7 @@ static int gdb_handle_packet(GDBState *s, const char *line_buf)
             if (s->query_cpu) {
                 snprintf(buf, sizeof(buf), "m%x", cpu_index(s->query_cpu));
                 put_packet(s, buf);
-                s->query_cpu = s->query_cpu->next_cpu;
+                s->query_cpu = CPU_NEXT(s->query_cpu);
             } else
                 put_packet(s, "l");
             break;
diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index 2cbeefd..1e313af 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -468,7 +468,7 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
     }
     info->is_linux = is_linux;
 
-    for (; cs; cs = cs->next_cpu) {
+    for (; cs; cs = CPU_NEXT(cs)) {
         cpu = ARM_CPU(cs);
         cpu->env.boot_info = info;
         qemu_register_reset(do_cpu_reset, cpu);
diff --git a/hw/i386/kvm/clock.c b/hw/i386/kvm/clock.c
index e89e2f7..92aabb8 100644
--- a/hw/i386/kvm/clock.c
+++ b/hw/i386/kvm/clock.c
@@ -59,7 +59,7 @@ static void kvmclock_vm_state_change(void *opaque, int running,
         if (!cap_clock_ctrl) {
             return;
         }
-        for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        CPU_FOREACH(cpu) {
             ret = kvm_vcpu_ioctl(cpu, KVM_KVMCLOCK_CTRL, 0);
             if (ret) {
                 if (ret != -EINVAL) {
diff --git a/hw/i386/kvmvapic.c b/hw/i386/kvmvapic.c
index a4506bc..cb860d5 100644
--- a/hw/i386/kvmvapic.c
+++ b/hw/i386/kvmvapic.c
@@ -498,7 +498,7 @@ static void vapic_enable_tpr_reporting(bool enable)
     X86CPU *cpu;
     CPUX86State *env;
 
-    for (cs = first_cpu; cs != NULL; cs = cs->next_cpu) {
+    CPU_FOREACH(cs) {
         cpu = X86_CPU(cs);
         env = &cpu->env;
         info.apic = env->apic_state;
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 2a87563..22f62c5 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -192,13 +192,12 @@ static void pic_irq_request(void *opaque, int irq, int level)
 
     DPRINTF("pic_irqs: %s irq %d\n", level? "raise" : "lower", irq);
     if (env->apic_state) {
-        while (cs) {
+        CPU_FOREACH(cs) {
             cpu = X86_CPU(cs);
             env = &cpu->env;
             if (apic_accept_pic_intr(env->apic_state)) {
                 apic_deliver_pic_intr(env->apic_state, level);
             }
-            cs = cs->next_cpu;
         }
     } else {
         if (level) {
diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c
index f00a62a..c2876fe 100644
--- a/hw/ppc/e500.c
+++ b/hw/ppc/e500.c
@@ -505,7 +505,7 @@ static DeviceState *ppce500_init_mpic_kvm(PPCE500Params *params,
         return NULL;
     }
 
-    for (cs = first_cpu; cs != NULL; cs = cs->next_cpu) {
+    CPU_FOREACH(cs) {
         if (kvm_openpic_connect_vcpu(dev, cs)) {
             fprintf(stderr, "%s: failed to connect vcpu to irqchip\n",
                     __func__);
diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c
index e1c095c..17f47e4 100644
--- a/hw/ppc/ppc.c
+++ b/hw/ppc/ppc.c
@@ -443,7 +443,7 @@ void ppce500_set_mpic_proxy(bool enabled)
 {
     CPUState *cs;
 
-    for (cs = first_cpu; cs != NULL; cs = cs->next_cpu) {
+    CPU_FOREACH(cs) {
         PowerPCCPU *cpu = POWERPC_CPU(cs);
 
         cpu->env.mpic_proxy = enabled;
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 16bfab9..84a26c5 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -167,7 +167,7 @@ static int spapr_fixup_cpu_dt(void *fdt, sPAPREnvironment *spapr)
 
     assert(spapr->cpu_model);
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         uint32_t associativity[] = {cpu_to_be32(0x5),
                                     cpu_to_be32(0x0),
                                     cpu_to_be32(0x0),
@@ -331,7 +331,7 @@ static void *spapr_create_fdt_skel(const char *cpu_model,
     /* This is needed during FDT finalization */
     spapr->cpu_model = g_strdup(modelname);
 
-    for (cs = first_cpu; cs != NULL; cs = cs->next_cpu) {
+    CPU_FOREACH(cs) {
         PowerPCCPU *cpu = POWERPC_CPU(cs);
         CPUPPCState *env = &cpu->env;
         PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cs);
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index 0d6e95c..6d052ee 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -23,6 +23,7 @@
 #include <signal.h>
 #include "hw/qdev-core.h"
 #include "exec/hwaddr.h"
+#include "qemu/queue.h"
 #include "qemu/thread.h"
 #include "qemu/tls.h"
 #include "qemu/typedefs.h"
@@ -188,7 +189,7 @@ struct CPUState {
     struct TranslationBlock *current_tb;
     struct GDBRegisterState *gdb_regs;
     int gdb_num_regs;
-    CPUState *next_cpu;
+    QTAILQ_ENTRY(CPUState) node;
 
     int kvm_fd;
     bool kvm_vcpu_dirty;
@@ -200,7 +201,13 @@ struct CPUState {
     uint32_t halted; /* used by alpha, cris, ppc TCG */
 };
 
-extern CPUState *first_cpu;
+QTAILQ_HEAD(CPUTailQ, CPUState);
+extern struct CPUTailQ cpus;
+#define CPU_NEXT(cpu) QTAILQ_NEXT(cpu, node)
+#define CPU_FOREACH(cpu) QTAILQ_FOREACH(cpu, &cpus, node)
+#define CPU_FOREACH_SAFE(cpu, next_cpu) \
+    QTAILQ_FOREACH_SAFE(cpu, &cpus, node, next_cpu)
+#define first_cpu QTAILQ_FIRST(&cpus)
 
 DECLARE_TLS(CPUState *, current_cpu);
 #define current_cpu tls_var(current_cpu)
diff --git a/kvm-all.c b/kvm-all.c
index 716860f..52df2a4 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1933,7 +1933,7 @@ int kvm_insert_breakpoint(CPUState *cpu, target_ulong addr,
         }
     }
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         err = kvm_update_guest_debug(cpu, 0);
         if (err) {
             return err;
@@ -1973,7 +1973,7 @@ int kvm_remove_breakpoint(CPUState *cpu, target_ulong addr,
         }
     }
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         err = kvm_update_guest_debug(cpu, 0);
         if (err) {
             return err;
@@ -1990,7 +1990,7 @@ void kvm_remove_all_breakpoints(CPUState *cpu)
     QTAILQ_FOREACH_SAFE(bp, &s->kvm_sw_breakpoints, entry, next) {
         if (kvm_arch_remove_sw_breakpoint(cpu, bp) != 0) {
             /* Try harder to find a CPU that currently sees the breakpoint. */
-            for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+            CPU_FOREACH(cpu) {
                 if (kvm_arch_remove_sw_breakpoint(cpu, bp) == 0) {
                     break;
                 }
@@ -2001,7 +2001,7 @@ void kvm_remove_all_breakpoints(CPUState *cpu)
     }
     kvm_arch_remove_all_hw_breakpoints();
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         kvm_update_guest_debug(cpu, 0);
     }
 }
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 7ce2eab..72d9270 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -2668,7 +2668,7 @@ static int fill_note_info(struct elf_note_info *info,
 
     /* read and fill status of all threads */
     cpu_list_lock();
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         if (cpu == thread_cpu) {
             continue;
         }
diff --git a/linux-user/main.c b/linux-user/main.c
index 03859bc..5c2f7b2 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -117,10 +117,14 @@ void fork_end(int child)
 {
     mmap_fork_end(child);
     if (child) {
+        CPUState *cpu, *next_cpu;
         /* Child processes created by fork() only have a single thread.
            Discard information about the parent threads.  */
-        first_cpu = thread_cpu;
-        first_cpu->next_cpu = NULL;
+        CPU_FOREACH_SAFE(cpu, next_cpu) {
+            if (cpu != thread_cpu) {
+                QTAILQ_REMOVE(&cpus, thread_cpu, node);
+            }
+        }
         pending_cpus = 0;
         pthread_mutex_init(&exclusive_lock, NULL);
         pthread_mutex_init(&cpu_list_mutex, NULL);
@@ -154,7 +158,7 @@ static inline void start_exclusive(void)
 
     pending_cpus = 1;
     /* Make all other cpus stop executing.  */
-    for (other_cpu = first_cpu; other_cpu; other_cpu = other_cpu->next_cpu) {
+    CPU_FOREACH(other_cpu) {
         if (other_cpu->running) {
             pending_cpus++;
             cpu_exit(other_cpu);
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 3f6db4b..0044196 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -5113,25 +5113,12 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
            Do thread termination if we have more then one thread.  */
         /* FIXME: This probably breaks if a signal arrives.  We should probably
            be disabling signals.  */
-        if (first_cpu->next_cpu) {
+        if (CPU_NEXT(first_cpu)) {
             TaskState *ts;
-            CPUState **lastp;
-            CPUState *p;
 
             cpu_list_lock();
-            lastp = &first_cpu;
-            p = first_cpu;
-            while (p && p != cpu) {
-                lastp = &p->next_cpu;
-                p = p->next_cpu;
-            }
-            /* If we didn't find the CPU for this thread then something is
-               horribly wrong.  */
-            if (!p) {
-                abort();
-            }
             /* Remove the CPU from the list.  */
-            *lastp = p->next_cpu;
+            QTAILQ_REMOVE(&cpus, cpu, node);
             cpu_list_unlock();
             ts = ((CPUArchState *)cpu_env)->opaque;
             if (ts->child_tidptr) {
diff --git a/memory_mapping.c b/memory_mapping.c
index 515a984..a50ca53 100644
--- a/memory_mapping.c
+++ b/memory_mapping.c
@@ -169,7 +169,7 @@ static CPUState *find_paging_enabled_cpu(CPUState *start_cpu)
 {
     CPUState *cpu;
 
-    for (cpu = start_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         if (cpu_paging_enabled(cpu)) {
             return cpu;
         }
@@ -186,7 +186,8 @@ void qemu_get_guest_memory_mapping(MemoryMappingList *list, Error **errp)
 
     first_paging_enabled_cpu = find_paging_enabled_cpu(first_cpu);
     if (first_paging_enabled_cpu) {
-        for (cpu = first_paging_enabled_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        for (cpu = first_paging_enabled_cpu; cpu != NULL;
+             cpu = CPU_NEXT(cpu)) {
             Error *err = NULL;
             cpu_get_memory_mapping(cpu, list, &err);
             if (err) {
diff --git a/monitor.c b/monitor.c
index 5dc0aa9..2ac1ce3 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1819,7 +1819,7 @@ static void do_info_numa(Monitor *mon, const QDict *qdict)
     monitor_printf(mon, "%d nodes\n", nb_numa_nodes);
     for (i = 0; i < nb_numa_nodes; i++) {
         monitor_printf(mon, "node %d cpus:", i);
-        for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        CPU_FOREACH(cpu) {
             if (cpu->numa_node == i) {
                 monitor_printf(mon, " %d", cpu->cpu_index);
             }
diff --git a/target-i386/helper.c b/target-i386/helper.c
index bf3e2ac..7c58e27 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -1231,8 +1231,7 @@ void cpu_x86_inject_mce(Monitor *mon, X86CPU *cpu, int bank,
         params.mcg_status = MCG_STATUS_MCIP | MCG_STATUS_RIPV;
         params.addr = 0;
         params.misc = 0;
-        for (other_cs = first_cpu; other_cs != NULL;
-             other_cs = other_cs->next_cpu) {
+        CPU_FOREACH(other_cs) {
             if (other_cs == cs) {
                 continue;
             }
diff --git a/target-i386/misc_helper.c b/target-i386/misc_helper.c
index 957926c..93933fd 100644
--- a/target-i386/misc_helper.c
+++ b/target-i386/misc_helper.c
@@ -610,7 +610,7 @@ void helper_mwait(CPUX86State *env, int next_eip_addend)
     cpu = x86_env_get_cpu(env);
     cs = CPU(cpu);
     /* XXX: not complete but not completely erroneous */
-    if (cs->cpu_index != 0 || cs->next_cpu != NULL) {
+    if (cs->cpu_index != 0 || CPU_NEXT(cs) != NULL) {
         /* more than one CPU: do not sleep because another CPU may
            wake this one */
     } else {
diff --git a/target-mips/op_helper.c b/target-mips/op_helper.c
index b828375..8e3a6d7 100644
--- a/target-mips/op_helper.c
+++ b/target-mips/op_helper.c
@@ -1699,15 +1699,14 @@ target_ulong helper_dvpe(CPUMIPSState *env)
     CPUState *other_cs = first_cpu;
     target_ulong prev = env->mvp->CP0_MVPControl;
 
-    do {
+    CPU_FOREACH(other_cs) {
         MIPSCPU *other_cpu = MIPS_CPU(other_cs);
         /* Turn off all VPEs except the one executing the dvpe.  */
         if (&other_cpu->env != env) {
             other_cpu->env.mvp->CP0_MVPControl &= ~(1 << CP0MVPCo_EVP);
             mips_vpe_sleep(other_cpu);
         }
-        other_cs = other_cs->next_cpu;
-    } while (other_cs);
+    }
     return prev;
 }
 
@@ -1716,7 +1715,7 @@ target_ulong helper_evpe(CPUMIPSState *env)
     CPUState *other_cs = first_cpu;
     target_ulong prev = env->mvp->CP0_MVPControl;
 
-    do {
+    CPU_FOREACH(other_cs) {
         MIPSCPU *other_cpu = MIPS_CPU(other_cs);
 
         if (&other_cpu->env != env
@@ -1726,8 +1725,7 @@ target_ulong helper_evpe(CPUMIPSState *env)
             other_cpu->env.mvp->CP0_MVPControl |= (1 << CP0MVPCo_EVP);
             mips_vpe_wake(other_cpu); /* And wake it up.  */
         }
-        other_cs = other_cs->next_cpu;
-    } while (other_cs);
+    }
     return prev;
 }
 #endif /* !CONFIG_USER_ONLY */
diff --git a/target-ppc/excp_helper.c b/target-ppc/excp_helper.c
index e9fcad8..df7886a 100644
--- a/target-ppc/excp_helper.c
+++ b/target-ppc/excp_helper.c
@@ -992,7 +992,7 @@ void helper_msgsnd(target_ulong rb)
         return;
     }
 
-    for (cs = first_cpu; cs != NULL; cs = cs->next_cpu) {
+    CPU_FOREACH(cs) {
         PowerPCCPU *cpu = POWERPC_CPU(cs);
         CPUPPCState *cenv = &cpu->env;
 
diff --git a/translate-all.c b/translate-all.c
index 3b5fc7c..2c923c6 100644
--- a/translate-all.c
+++ b/translate-all.c
@@ -696,7 +696,7 @@ void tb_flush(CPUArchState *env1)
     }
     tcg_ctx.tb_ctx.nb_tbs = 0;
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         CPUArchState *env = cpu->env_ptr;
 
         memset(env->tb_jmp_cache, 0, TB_JMP_CACHE_SIZE * sizeof(void *));
@@ -850,7 +850,7 @@ void tb_phys_invalidate(TranslationBlock *tb, tb_page_addr_t page_addr)
 
     /* remove the TB from the hash list */
     h = tb_jmp_cache_hash_func(tb->pc);
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         CPUArchState *env = cpu->env_ptr;
 
         if (env->tb_jmp_cache[h] == tb) {
-- 
1.8.1.4


^ permalink raw reply related	[flat|nested] 13+ messages in thread

* [Qemu-devel] [PATCH qom-cpu for-next 1/2] cpu: Use QTAILQ for CPU list
@ 2013-07-30 16:55   ` Andreas Färber
  0 siblings, 0 replies; 13+ messages in thread
From: Andreas Färber @ 2013-07-30 16:55 UTC (permalink / raw)
  To: qemu-devel
  Cc: Peter Maydell, Anthony Liguori, open list:Overall, Gleb Natapov,
	Riku Voipio, Alexander Graf, Luiz Capitulino, open list:e500,
	Paul Brook, Scott Wood, Paolo Bonzini, Andreas Färber,
	Aurelien Jarno

Introduce CPU_FOREACH(), CPU_FOREACH_SAFE() and CPU_NEXT() shorthand
macros.

Signed-off-by: Andreas Färber <afaerber@suse.de>
---
 cpus.c                    | 47 ++++++++++++++++++++---------------------------
 cputlb.c                  |  2 +-
 dump.c                    | 10 +++++-----
 exec.c                    | 26 ++++++++++----------------
 gdbstub.c                 | 14 +++++++-------
 hw/arm/boot.c             |  2 +-
 hw/i386/kvm/clock.c       |  2 +-
 hw/i386/kvmvapic.c        |  2 +-
 hw/i386/pc.c              |  3 +--
 hw/ppc/e500.c             |  2 +-
 hw/ppc/ppc.c              |  2 +-
 hw/ppc/spapr.c            |  4 ++--
 include/qom/cpu.h         | 11 +++++++++--
 kvm-all.c                 |  8 ++++----
 linux-user/elfload.c      |  2 +-
 linux-user/main.c         | 10 +++++++---
 linux-user/syscall.c      | 17 ++---------------
 memory_mapping.c          |  5 +++--
 monitor.c                 |  2 +-
 target-i386/helper.c      |  3 +--
 target-i386/misc_helper.c |  2 +-
 target-mips/op_helper.c   | 10 ++++------
 target-ppc/excp_helper.c  |  2 +-
 translate-all.c           |  4 ++--
 24 files changed, 87 insertions(+), 105 deletions(-)

diff --git a/cpus.c b/cpus.c
index 0f65e76..1e2fd8a 100644
--- a/cpus.c
+++ b/cpus.c
@@ -81,7 +81,7 @@ static bool all_cpu_threads_idle(void)
 {
     CPUState *cpu;
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         if (!cpu_thread_is_idle(cpu)) {
             return false;
         }
@@ -394,7 +394,7 @@ void hw_error(const char *fmt, ...)
     fprintf(stderr, "qemu: hardware error: ");
     vfprintf(stderr, fmt, ap);
     fprintf(stderr, "\n");
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         fprintf(stderr, "CPU #%d:\n", cpu->cpu_index);
         cpu_dump_state(cpu, stderr, fprintf, CPU_DUMP_FPU);
     }
@@ -406,7 +406,7 @@ void cpu_synchronize_all_states(void)
 {
     CPUState *cpu;
 
-    for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         cpu_synchronize_state(cpu);
     }
 }
@@ -415,7 +415,7 @@ void cpu_synchronize_all_post_reset(void)
 {
     CPUState *cpu;
 
-    for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         cpu_synchronize_post_reset(cpu);
     }
 }
@@ -424,7 +424,7 @@ void cpu_synchronize_all_post_init(void)
 {
     CPUState *cpu;
 
-    for (cpu = first_cpu; cpu; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         cpu_synchronize_post_init(cpu);
     }
 }
@@ -743,7 +743,7 @@ static void qemu_tcg_wait_io_event(void)
         qemu_cond_wait(&qemu_io_proceeded_cond, &qemu_global_mutex);
     }
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         qemu_wait_io_event_common(cpu);
     }
 }
@@ -855,11 +855,11 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
     qemu_cond_signal(&qemu_cpu_cond);
 
     /* wait for initial kick-off after machine start */
-    while (first_cpu->stopped) {
+    while (QTAILQ_FIRST(&cpus)->stopped) {
         qemu_cond_wait(tcg_halt_cond, &qemu_global_mutex);
 
         /* process any pending work */
-        for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        CPU_FOREACH(cpu) {
             qemu_wait_io_event_common(cpu);
         }
     }
@@ -969,13 +969,12 @@ void qemu_mutex_unlock_iothread(void)
 
 static int all_vcpus_paused(void)
 {
-    CPUState *cpu = first_cpu;
+    CPUState *cpu;
 
-    while (cpu) {
+    CPU_FOREACH(cpu) {
         if (!cpu->stopped) {
             return 0;
         }
-        cpu = cpu->next_cpu;
     }
 
     return 1;
@@ -983,23 +982,20 @@ static int all_vcpus_paused(void)
 
 void pause_all_vcpus(void)
 {
-    CPUState *cpu = first_cpu;
+    CPUState *cpu;
 
     qemu_clock_enable(vm_clock, false);
-    while (cpu) {
+    CPU_FOREACH(cpu) {
         cpu->stop = true;
         qemu_cpu_kick(cpu);
-        cpu = cpu->next_cpu;
     }
 
     if (qemu_in_vcpu_thread()) {
         cpu_stop_current();
         if (!kvm_enabled()) {
-            cpu = first_cpu;
-            while (cpu) {
+            CPU_FOREACH(cpu) {
                 cpu->stop = false;
                 cpu->stopped = true;
-                cpu = cpu->next_cpu;
             }
             return;
         }
@@ -1007,10 +1003,8 @@ void pause_all_vcpus(void)
 
     while (!all_vcpus_paused()) {
         qemu_cond_wait(&qemu_pause_cond, &qemu_global_mutex);
-        cpu = first_cpu;
-        while (cpu) {
+        CPU_FOREACH(cpu) {
             qemu_cpu_kick(cpu);
-            cpu = cpu->next_cpu;
         }
     }
 }
@@ -1024,12 +1018,11 @@ void cpu_resume(CPUState *cpu)
 
 void resume_all_vcpus(void)
 {
-    CPUState *cpu = first_cpu;
+    CPUState *cpu;
 
     qemu_clock_enable(vm_clock, true);
-    while (cpu) {
+    CPU_FOREACH(cpu) {
         cpu_resume(cpu);
-        cpu = cpu->next_cpu;
     }
 }
 
@@ -1181,7 +1174,7 @@ static void tcg_exec_all(void)
     if (next_cpu == NULL) {
         next_cpu = first_cpu;
     }
-    for (; next_cpu != NULL && !exit_request; next_cpu = next_cpu->next_cpu) {
+    for (; next_cpu != NULL && !exit_request; next_cpu = CPU_NEXT(next_cpu)) {
         CPUState *cpu = next_cpu;
         CPUArchState *env = cpu->env_ptr;
 
@@ -1206,7 +1199,7 @@ void set_numa_modes(void)
     CPUState *cpu;
     int i;
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         for (i = 0; i < nb_numa_nodes; i++) {
             if (test_bit(cpu->cpu_index, node_cpumask[i])) {
                 cpu->numa_node = i;
@@ -1228,7 +1221,7 @@ CpuInfoList *qmp_query_cpus(Error **errp)
     CpuInfoList *head = NULL, *cur_item = NULL;
     CPUState *cpu;
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         CpuInfoList *info;
 #if defined(TARGET_I386)
         X86CPU *x86_cpu = X86_CPU(cpu);
@@ -1357,7 +1350,7 @@ void qmp_inject_nmi(Error **errp)
 #if defined(TARGET_I386)
     CPUState *cs;
 
-    for (cs = first_cpu; cs != NULL; cs = cs->next_cpu) {
+    CPU_FOREACH(cs) {
         X86CPU *cpu = X86_CPU(cs);
         CPUX86State *env = &cpu->env;
 
diff --git a/cputlb.c b/cputlb.c
index 977c0ca..19ecf60 100644
--- a/cputlb.c
+++ b/cputlb.c
@@ -189,7 +189,7 @@ void cpu_tlb_reset_dirty_all(ram_addr_t start1, ram_addr_t length)
     CPUState *cpu;
     CPUArchState *env;
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         int mmu_idx;
 
         env = cpu->env_ptr;
diff --git a/dump.c b/dump.c
index 6a3a72a..dac97a3 100644
--- a/dump.c
+++ b/dump.c
@@ -279,7 +279,7 @@ static int write_elf64_notes(DumpState *s)
     int ret;
     int id;
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         id = cpu_index(cpu);
         ret = cpu_write_elf64_note(fd_write_vmcore, cpu, id, s);
         if (ret < 0) {
@@ -288,7 +288,7 @@ static int write_elf64_notes(DumpState *s)
         }
     }
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         ret = cpu_write_elf64_qemunote(fd_write_vmcore, cpu, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to write CPU status.\n");
@@ -329,7 +329,7 @@ static int write_elf32_notes(DumpState *s)
     int ret;
     int id;
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         id = cpu_index(cpu);
         ret = cpu_write_elf32_note(fd_write_vmcore, cpu, id, s);
         if (ret < 0) {
@@ -338,7 +338,7 @@ static int write_elf32_notes(DumpState *s)
         }
     }
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         ret = cpu_write_elf32_qemunote(fd_write_vmcore, cpu, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to write CPU status.\n");
@@ -734,7 +734,7 @@ static int dump_init(DumpState *s, int fd, bool paging, bool has_filter,
      */
     cpu_synchronize_all_states();
     nr_cpus = 0;
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         nr_cpus++;
     }
 
diff --git a/exec.c b/exec.c
index c4f2894..4ee61a6 100644
--- a/exec.c
+++ b/exec.c
@@ -69,7 +69,7 @@ static MemoryRegion io_mem_unassigned;
 
 #endif
 
-CPUState *first_cpu;
+struct CPUTailQ cpus = QTAILQ_HEAD_INITIALIZER(cpus);
 /* current CPU in the current thread. It is only valid inside
    cpu_exec() */
 DEFINE_TLS(CPUState *, current_cpu);
@@ -351,26 +351,23 @@ const VMStateDescription vmstate_cpu_common = {
 
 CPUState *qemu_get_cpu(int index)
 {
-    CPUState *cpu = first_cpu;
+    CPUState *cpu;
 
-    while (cpu) {
+    CPU_FOREACH(cpu) {
         if (cpu->cpu_index == index) {
-            break;
+            return cpu;
         }
-        cpu = cpu->next_cpu;
     }
 
-    return cpu;
+    return NULL;
 }
 
 void qemu_for_each_cpu(void (*func)(CPUState *cpu, void *data), void *data)
 {
     CPUState *cpu;
 
-    cpu = first_cpu;
-    while (cpu) {
+    CPU_FOREACH(cpu) {
         func(cpu, data);
-        cpu = cpu->next_cpu;
     }
 }
 
@@ -378,17 +375,14 @@ void cpu_exec_init(CPUArchState *env)
 {
     CPUState *cpu = ENV_GET_CPU(env);
     CPUClass *cc = CPU_GET_CLASS(cpu);
-    CPUState **pcpu;
+    CPUState *some_cpu;
     int cpu_index;
 
 #if defined(CONFIG_USER_ONLY)
     cpu_list_lock();
 #endif
-    cpu->next_cpu = NULL;
-    pcpu = &first_cpu;
     cpu_index = 0;
-    while (*pcpu != NULL) {
-        pcpu = &(*pcpu)->next_cpu;
+    CPU_FOREACH(some_cpu) {
         cpu_index++;
     }
     cpu->cpu_index = cpu_index;
@@ -398,7 +392,7 @@ void cpu_exec_init(CPUArchState *env)
 #ifndef CONFIG_USER_ONLY
     cpu->thread_id = qemu_get_thread_id();
 #endif
-    *pcpu = cpu;
+    QTAILQ_INSERT_TAIL(&cpus, cpu, node);
 #if defined(CONFIG_USER_ONLY)
     cpu_list_unlock();
 #endif
@@ -1759,7 +1753,7 @@ static void tcg_commit(MemoryListener *listener)
     /* since each CPU stores ram addresses in its TLB cache, we must
        reset the modified entries */
     /* XXX: slow ! */
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         CPUArchState *env = cpu->env_ptr;
 
         tlb_flush(env, 1);
diff --git a/gdbstub.c b/gdbstub.c
index 1af25a6..ae53df0 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -646,7 +646,7 @@ static int gdb_breakpoint_insert(target_ulong addr, target_ulong len, int type)
     switch (type) {
     case GDB_BREAKPOINT_SW:
     case GDB_BREAKPOINT_HW:
-        for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        CPU_FOREACH(cpu) {
             env = cpu->env_ptr;
             err = cpu_breakpoint_insert(env, addr, BP_GDB, NULL);
             if (err)
@@ -657,7 +657,7 @@ static int gdb_breakpoint_insert(target_ulong addr, target_ulong len, int type)
     case GDB_WATCHPOINT_WRITE:
     case GDB_WATCHPOINT_READ:
     case GDB_WATCHPOINT_ACCESS:
-        for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        CPU_FOREACH(cpu) {
             env = cpu->env_ptr;
             err = cpu_watchpoint_insert(env, addr, len, xlat_gdb_type[type],
                                         NULL);
@@ -684,7 +684,7 @@ static int gdb_breakpoint_remove(target_ulong addr, target_ulong len, int type)
     switch (type) {
     case GDB_BREAKPOINT_SW:
     case GDB_BREAKPOINT_HW:
-        for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        CPU_FOREACH(cpu) {
             env = cpu->env_ptr;
             err = cpu_breakpoint_remove(env, addr, BP_GDB);
             if (err)
@@ -695,7 +695,7 @@ static int gdb_breakpoint_remove(target_ulong addr, target_ulong len, int type)
     case GDB_WATCHPOINT_WRITE:
     case GDB_WATCHPOINT_READ:
     case GDB_WATCHPOINT_ACCESS:
-        for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        CPU_FOREACH(cpu) {
             env = cpu->env_ptr;
             err = cpu_watchpoint_remove(env, addr, len, xlat_gdb_type[type]);
             if (err)
@@ -718,7 +718,7 @@ static void gdb_breakpoint_remove_all(void)
         return;
     }
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         env = cpu->env_ptr;
         cpu_breakpoint_remove_all(env, BP_GDB);
 #ifndef CONFIG_USER_ONLY
@@ -742,7 +742,7 @@ static CPUState *find_cpu(uint32_t thread_id)
 {
     CPUState *cpu;
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         if (cpu_index(cpu) == thread_id) {
             return cpu;
         }
@@ -1068,7 +1068,7 @@ static int gdb_handle_packet(GDBState *s, const char *line_buf)
             if (s->query_cpu) {
                 snprintf(buf, sizeof(buf), "m%x", cpu_index(s->query_cpu));
                 put_packet(s, buf);
-                s->query_cpu = s->query_cpu->next_cpu;
+                s->query_cpu = CPU_NEXT(s->query_cpu);
             } else
                 put_packet(s, "l");
             break;
diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index 2cbeefd..1e313af 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -468,7 +468,7 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
     }
     info->is_linux = is_linux;
 
-    for (; cs; cs = cs->next_cpu) {
+    for (; cs; cs = CPU_NEXT(cs)) {
         cpu = ARM_CPU(cs);
         cpu->env.boot_info = info;
         qemu_register_reset(do_cpu_reset, cpu);
diff --git a/hw/i386/kvm/clock.c b/hw/i386/kvm/clock.c
index e89e2f7..92aabb8 100644
--- a/hw/i386/kvm/clock.c
+++ b/hw/i386/kvm/clock.c
@@ -59,7 +59,7 @@ static void kvmclock_vm_state_change(void *opaque, int running,
         if (!cap_clock_ctrl) {
             return;
         }
-        for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        CPU_FOREACH(cpu) {
             ret = kvm_vcpu_ioctl(cpu, KVM_KVMCLOCK_CTRL, 0);
             if (ret) {
                 if (ret != -EINVAL) {
diff --git a/hw/i386/kvmvapic.c b/hw/i386/kvmvapic.c
index a4506bc..cb860d5 100644
--- a/hw/i386/kvmvapic.c
+++ b/hw/i386/kvmvapic.c
@@ -498,7 +498,7 @@ static void vapic_enable_tpr_reporting(bool enable)
     X86CPU *cpu;
     CPUX86State *env;
 
-    for (cs = first_cpu; cs != NULL; cs = cs->next_cpu) {
+    CPU_FOREACH(cs) {
         cpu = X86_CPU(cs);
         env = &cpu->env;
         info.apic = env->apic_state;
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 2a87563..22f62c5 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -192,13 +192,12 @@ static void pic_irq_request(void *opaque, int irq, int level)
 
     DPRINTF("pic_irqs: %s irq %d\n", level? "raise" : "lower", irq);
     if (env->apic_state) {
-        while (cs) {
+        CPU_FOREACH(cs) {
             cpu = X86_CPU(cs);
             env = &cpu->env;
             if (apic_accept_pic_intr(env->apic_state)) {
                 apic_deliver_pic_intr(env->apic_state, level);
             }
-            cs = cs->next_cpu;
         }
     } else {
         if (level) {
diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c
index f00a62a..c2876fe 100644
--- a/hw/ppc/e500.c
+++ b/hw/ppc/e500.c
@@ -505,7 +505,7 @@ static DeviceState *ppce500_init_mpic_kvm(PPCE500Params *params,
         return NULL;
     }
 
-    for (cs = first_cpu; cs != NULL; cs = cs->next_cpu) {
+    CPU_FOREACH(cs) {
         if (kvm_openpic_connect_vcpu(dev, cs)) {
             fprintf(stderr, "%s: failed to connect vcpu to irqchip\n",
                     __func__);
diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c
index e1c095c..17f47e4 100644
--- a/hw/ppc/ppc.c
+++ b/hw/ppc/ppc.c
@@ -443,7 +443,7 @@ void ppce500_set_mpic_proxy(bool enabled)
 {
     CPUState *cs;
 
-    for (cs = first_cpu; cs != NULL; cs = cs->next_cpu) {
+    CPU_FOREACH(cs) {
         PowerPCCPU *cpu = POWERPC_CPU(cs);
 
         cpu->env.mpic_proxy = enabled;
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 16bfab9..84a26c5 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -167,7 +167,7 @@ static int spapr_fixup_cpu_dt(void *fdt, sPAPREnvironment *spapr)
 
     assert(spapr->cpu_model);
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         uint32_t associativity[] = {cpu_to_be32(0x5),
                                     cpu_to_be32(0x0),
                                     cpu_to_be32(0x0),
@@ -331,7 +331,7 @@ static void *spapr_create_fdt_skel(const char *cpu_model,
     /* This is needed during FDT finalization */
     spapr->cpu_model = g_strdup(modelname);
 
-    for (cs = first_cpu; cs != NULL; cs = cs->next_cpu) {
+    CPU_FOREACH(cs) {
         PowerPCCPU *cpu = POWERPC_CPU(cs);
         CPUPPCState *env = &cpu->env;
         PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cs);
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index 0d6e95c..6d052ee 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -23,6 +23,7 @@
 #include <signal.h>
 #include "hw/qdev-core.h"
 #include "exec/hwaddr.h"
+#include "qemu/queue.h"
 #include "qemu/thread.h"
 #include "qemu/tls.h"
 #include "qemu/typedefs.h"
@@ -188,7 +189,7 @@ struct CPUState {
     struct TranslationBlock *current_tb;
     struct GDBRegisterState *gdb_regs;
     int gdb_num_regs;
-    CPUState *next_cpu;
+    QTAILQ_ENTRY(CPUState) node;
 
     int kvm_fd;
     bool kvm_vcpu_dirty;
@@ -200,7 +201,13 @@ struct CPUState {
     uint32_t halted; /* used by alpha, cris, ppc TCG */
 };
 
-extern CPUState *first_cpu;
+QTAILQ_HEAD(CPUTailQ, CPUState);
+extern struct CPUTailQ cpus;
+#define CPU_NEXT(cpu) QTAILQ_NEXT(cpu, node)
+#define CPU_FOREACH(cpu) QTAILQ_FOREACH(cpu, &cpus, node)
+#define CPU_FOREACH_SAFE(cpu, next_cpu) \
+    QTAILQ_FOREACH_SAFE(cpu, &cpus, node, next_cpu)
+#define first_cpu QTAILQ_FIRST(&cpus)
 
 DECLARE_TLS(CPUState *, current_cpu);
 #define current_cpu tls_var(current_cpu)
diff --git a/kvm-all.c b/kvm-all.c
index 716860f..52df2a4 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1933,7 +1933,7 @@ int kvm_insert_breakpoint(CPUState *cpu, target_ulong addr,
         }
     }
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         err = kvm_update_guest_debug(cpu, 0);
         if (err) {
             return err;
@@ -1973,7 +1973,7 @@ int kvm_remove_breakpoint(CPUState *cpu, target_ulong addr,
         }
     }
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         err = kvm_update_guest_debug(cpu, 0);
         if (err) {
             return err;
@@ -1990,7 +1990,7 @@ void kvm_remove_all_breakpoints(CPUState *cpu)
     QTAILQ_FOREACH_SAFE(bp, &s->kvm_sw_breakpoints, entry, next) {
         if (kvm_arch_remove_sw_breakpoint(cpu, bp) != 0) {
             /* Try harder to find a CPU that currently sees the breakpoint. */
-            for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+            CPU_FOREACH(cpu) {
                 if (kvm_arch_remove_sw_breakpoint(cpu, bp) == 0) {
                     break;
                 }
@@ -2001,7 +2001,7 @@ void kvm_remove_all_breakpoints(CPUState *cpu)
     }
     kvm_arch_remove_all_hw_breakpoints();
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         kvm_update_guest_debug(cpu, 0);
     }
 }
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 7ce2eab..72d9270 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -2668,7 +2668,7 @@ static int fill_note_info(struct elf_note_info *info,
 
     /* read and fill status of all threads */
     cpu_list_lock();
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         if (cpu == thread_cpu) {
             continue;
         }
diff --git a/linux-user/main.c b/linux-user/main.c
index 03859bc..5c2f7b2 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -117,10 +117,14 @@ void fork_end(int child)
 {
     mmap_fork_end(child);
     if (child) {
+        CPUState *cpu, *next_cpu;
         /* Child processes created by fork() only have a single thread.
            Discard information about the parent threads.  */
-        first_cpu = thread_cpu;
-        first_cpu->next_cpu = NULL;
+        CPU_FOREACH_SAFE(cpu, next_cpu) {
+            if (cpu != thread_cpu) {
+                QTAILQ_REMOVE(&cpus, thread_cpu, node);
+            }
+        }
         pending_cpus = 0;
         pthread_mutex_init(&exclusive_lock, NULL);
         pthread_mutex_init(&cpu_list_mutex, NULL);
@@ -154,7 +158,7 @@ static inline void start_exclusive(void)
 
     pending_cpus = 1;
     /* Make all other cpus stop executing.  */
-    for (other_cpu = first_cpu; other_cpu; other_cpu = other_cpu->next_cpu) {
+    CPU_FOREACH(other_cpu) {
         if (other_cpu->running) {
             pending_cpus++;
             cpu_exit(other_cpu);
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 3f6db4b..0044196 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -5113,25 +5113,12 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
            Do thread termination if we have more then one thread.  */
         /* FIXME: This probably breaks if a signal arrives.  We should probably
            be disabling signals.  */
-        if (first_cpu->next_cpu) {
+        if (CPU_NEXT(first_cpu)) {
             TaskState *ts;
-            CPUState **lastp;
-            CPUState *p;
 
             cpu_list_lock();
-            lastp = &first_cpu;
-            p = first_cpu;
-            while (p && p != cpu) {
-                lastp = &p->next_cpu;
-                p = p->next_cpu;
-            }
-            /* If we didn't find the CPU for this thread then something is
-               horribly wrong.  */
-            if (!p) {
-                abort();
-            }
             /* Remove the CPU from the list.  */
-            *lastp = p->next_cpu;
+            QTAILQ_REMOVE(&cpus, cpu, node);
             cpu_list_unlock();
             ts = ((CPUArchState *)cpu_env)->opaque;
             if (ts->child_tidptr) {
diff --git a/memory_mapping.c b/memory_mapping.c
index 515a984..a50ca53 100644
--- a/memory_mapping.c
+++ b/memory_mapping.c
@@ -169,7 +169,7 @@ static CPUState *find_paging_enabled_cpu(CPUState *start_cpu)
 {
     CPUState *cpu;
 
-    for (cpu = start_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         if (cpu_paging_enabled(cpu)) {
             return cpu;
         }
@@ -186,7 +186,8 @@ void qemu_get_guest_memory_mapping(MemoryMappingList *list, Error **errp)
 
     first_paging_enabled_cpu = find_paging_enabled_cpu(first_cpu);
     if (first_paging_enabled_cpu) {
-        for (cpu = first_paging_enabled_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        for (cpu = first_paging_enabled_cpu; cpu != NULL;
+             cpu = CPU_NEXT(cpu)) {
             Error *err = NULL;
             cpu_get_memory_mapping(cpu, list, &err);
             if (err) {
diff --git a/monitor.c b/monitor.c
index 5dc0aa9..2ac1ce3 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1819,7 +1819,7 @@ static void do_info_numa(Monitor *mon, const QDict *qdict)
     monitor_printf(mon, "%d nodes\n", nb_numa_nodes);
     for (i = 0; i < nb_numa_nodes; i++) {
         monitor_printf(mon, "node %d cpus:", i);
-        for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+        CPU_FOREACH(cpu) {
             if (cpu->numa_node == i) {
                 monitor_printf(mon, " %d", cpu->cpu_index);
             }
diff --git a/target-i386/helper.c b/target-i386/helper.c
index bf3e2ac..7c58e27 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -1231,8 +1231,7 @@ void cpu_x86_inject_mce(Monitor *mon, X86CPU *cpu, int bank,
         params.mcg_status = MCG_STATUS_MCIP | MCG_STATUS_RIPV;
         params.addr = 0;
         params.misc = 0;
-        for (other_cs = first_cpu; other_cs != NULL;
-             other_cs = other_cs->next_cpu) {
+        CPU_FOREACH(other_cs) {
             if (other_cs == cs) {
                 continue;
             }
diff --git a/target-i386/misc_helper.c b/target-i386/misc_helper.c
index 957926c..93933fd 100644
--- a/target-i386/misc_helper.c
+++ b/target-i386/misc_helper.c
@@ -610,7 +610,7 @@ void helper_mwait(CPUX86State *env, int next_eip_addend)
     cpu = x86_env_get_cpu(env);
     cs = CPU(cpu);
     /* XXX: not complete but not completely erroneous */
-    if (cs->cpu_index != 0 || cs->next_cpu != NULL) {
+    if (cs->cpu_index != 0 || CPU_NEXT(cs) != NULL) {
         /* more than one CPU: do not sleep because another CPU may
            wake this one */
     } else {
diff --git a/target-mips/op_helper.c b/target-mips/op_helper.c
index b828375..8e3a6d7 100644
--- a/target-mips/op_helper.c
+++ b/target-mips/op_helper.c
@@ -1699,15 +1699,14 @@ target_ulong helper_dvpe(CPUMIPSState *env)
     CPUState *other_cs = first_cpu;
     target_ulong prev = env->mvp->CP0_MVPControl;
 
-    do {
+    CPU_FOREACH(other_cs) {
         MIPSCPU *other_cpu = MIPS_CPU(other_cs);
         /* Turn off all VPEs except the one executing the dvpe.  */
         if (&other_cpu->env != env) {
             other_cpu->env.mvp->CP0_MVPControl &= ~(1 << CP0MVPCo_EVP);
             mips_vpe_sleep(other_cpu);
         }
-        other_cs = other_cs->next_cpu;
-    } while (other_cs);
+    }
     return prev;
 }
 
@@ -1716,7 +1715,7 @@ target_ulong helper_evpe(CPUMIPSState *env)
     CPUState *other_cs = first_cpu;
     target_ulong prev = env->mvp->CP0_MVPControl;
 
-    do {
+    CPU_FOREACH(other_cs) {
         MIPSCPU *other_cpu = MIPS_CPU(other_cs);
 
         if (&other_cpu->env != env
@@ -1726,8 +1725,7 @@ target_ulong helper_evpe(CPUMIPSState *env)
             other_cpu->env.mvp->CP0_MVPControl |= (1 << CP0MVPCo_EVP);
             mips_vpe_wake(other_cpu); /* And wake it up.  */
         }
-        other_cs = other_cs->next_cpu;
-    } while (other_cs);
+    }
     return prev;
 }
 #endif /* !CONFIG_USER_ONLY */
diff --git a/target-ppc/excp_helper.c b/target-ppc/excp_helper.c
index e9fcad8..df7886a 100644
--- a/target-ppc/excp_helper.c
+++ b/target-ppc/excp_helper.c
@@ -992,7 +992,7 @@ void helper_msgsnd(target_ulong rb)
         return;
     }
 
-    for (cs = first_cpu; cs != NULL; cs = cs->next_cpu) {
+    CPU_FOREACH(cs) {
         PowerPCCPU *cpu = POWERPC_CPU(cs);
         CPUPPCState *cenv = &cpu->env;
 
diff --git a/translate-all.c b/translate-all.c
index 3b5fc7c..2c923c6 100644
--- a/translate-all.c
+++ b/translate-all.c
@@ -696,7 +696,7 @@ void tb_flush(CPUArchState *env1)
     }
     tcg_ctx.tb_ctx.nb_tbs = 0;
 
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         CPUArchState *env = cpu->env_ptr;
 
         memset(env->tb_jmp_cache, 0, TB_JMP_CACHE_SIZE * sizeof(void *));
@@ -850,7 +850,7 @@ void tb_phys_invalidate(TranslationBlock *tb, tb_page_addr_t page_addr)
 
     /* remove the TB from the hash list */
     h = tb_jmp_cache_hash_func(tb->pc);
-    for (cpu = first_cpu; cpu != NULL; cpu = cpu->next_cpu) {
+    CPU_FOREACH(cpu) {
         CPUArchState *env = cpu->env_ptr;
 
         if (env->tb_jmp_cache[h] == tb) {
-- 
1.8.1.4

^ permalink raw reply related	[flat|nested] 13+ messages in thread

* Re: [Qemu-devel] [PATCH qom-cpu for-next 1/2] cpu: Use QTAILQ for CPU list
  2013-07-30 16:55   ` [Qemu-devel] " Andreas Färber
@ 2013-08-21 14:12     ` Andreas Färber
  -1 siblings, 0 replies; 13+ messages in thread
From: Andreas Färber @ 2013-08-21 14:12 UTC (permalink / raw)
  To: Peter Maydell
  Cc: qemu-devel, Anthony Liguori, kvm, Gleb Natapov, Riku Voipio,
	Alexander Graf, Luiz Capitulino, qemu-ppc, Paul Brook, Scott Wood,
	Paolo Bonzini, Aurelien Jarno

Am 30.07.2013 18:55, schrieb Andreas Färber:
> Introduce CPU_FOREACH(), CPU_FOREACH_SAFE() and CPU_NEXT() shorthand
> macros.
> 
> Signed-off-by: Andreas Färber <afaerber@suse.de>

Needs the following addition now:

diff --git a/hw/cpu/a15mpcore.c b/hw/cpu/a15mpcore.c
index af182da..9d0e27e 100644
--- a/hw/cpu/a15mpcore.c
+++ b/hw/cpu/a15mpcore.c
@@ -72,9 +72,15 @@ static int a15mp_priv_init(SysBusDevice *dev)
     /* Wire the outputs from each CPU's generic timer to the
      * appropriate GIC PPI inputs
      */
-    for (i = 0, cpu = first_cpu; i < s->num_cpu; i++, cpu =
cpu->next_cpu) {
+    i = 0;
+    CPU_FOREACH(cpu) {
         DeviceState *cpudev = DEVICE(cpu);
         int ppibase = s->num_irq - 32 + i * 32;
+
+        if (i < s->num_cpu) {
+            break;
+        }
+
         /* physical timer; we wire it up to the non-secure timer's ID,
          * since a real A15 always has TrustZone but QEMU doesn't.
          */
@@ -83,6 +89,7 @@ static int a15mp_priv_init(SysBusDevice *dev)
         /* virtual timer */
         qdev_connect_gpio_out(cpudev, 1,
                               qdev_get_gpio_in(s->gic, ppibase + 27));
+        i++;
     }

     /* Memory map (addresses are offsets from PERIPHBASE):


-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

^ permalink raw reply related	[flat|nested] 13+ messages in thread

* Re: [Qemu-devel] [PATCH qom-cpu for-next 1/2] cpu: Use QTAILQ for CPU list
@ 2013-08-21 14:12     ` Andreas Färber
  0 siblings, 0 replies; 13+ messages in thread
From: Andreas Färber @ 2013-08-21 14:12 UTC (permalink / raw)
  To: Peter Maydell
  Cc: Anthony Liguori, Gleb Natapov, kvm, Riku Voipio, Alexander Graf,
	qemu-devel, qemu-ppc, Paul Brook, Scott Wood, Paolo Bonzini,
	Luiz Capitulino, Aurelien Jarno

Am 30.07.2013 18:55, schrieb Andreas Färber:
> Introduce CPU_FOREACH(), CPU_FOREACH_SAFE() and CPU_NEXT() shorthand
> macros.
> 
> Signed-off-by: Andreas Färber <afaerber@suse.de>

Needs the following addition now:

diff --git a/hw/cpu/a15mpcore.c b/hw/cpu/a15mpcore.c
index af182da..9d0e27e 100644
--- a/hw/cpu/a15mpcore.c
+++ b/hw/cpu/a15mpcore.c
@@ -72,9 +72,15 @@ static int a15mp_priv_init(SysBusDevice *dev)
     /* Wire the outputs from each CPU's generic timer to the
      * appropriate GIC PPI inputs
      */
-    for (i = 0, cpu = first_cpu; i < s->num_cpu; i++, cpu =
cpu->next_cpu) {
+    i = 0;
+    CPU_FOREACH(cpu) {
         DeviceState *cpudev = DEVICE(cpu);
         int ppibase = s->num_irq - 32 + i * 32;
+
+        if (i < s->num_cpu) {
+            break;
+        }
+
         /* physical timer; we wire it up to the non-secure timer's ID,
          * since a real A15 always has TrustZone but QEMU doesn't.
          */
@@ -83,6 +89,7 @@ static int a15mp_priv_init(SysBusDevice *dev)
         /* virtual timer */
         qdev_connect_gpio_out(cpudev, 1,
                               qdev_get_gpio_in(s->gic, ppibase + 27));
+        i++;
     }

     /* Memory map (addresses are offsets from PERIPHBASE):


-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

^ permalink raw reply related	[flat|nested] 13+ messages in thread

* Re: [Qemu-devel] [PATCH qom-cpu for-next 1/2] cpu: Use QTAILQ for CPU list
  2013-08-21 14:12     ` Andreas Färber
@ 2013-08-21 14:36       ` Peter Maydell
  -1 siblings, 0 replies; 13+ messages in thread
From: Peter Maydell @ 2013-08-21 14:36 UTC (permalink / raw)
  To: Andreas Färber
  Cc: QEMU Developers, Anthony Liguori, kvm, Gleb Natapov, Riku Voipio,
	Alexander Graf, Luiz Capitulino, qemu-ppc, Paul Brook, Scott Wood,
	Paolo Bonzini, Aurelien Jarno

On 21 August 2013 15:12, Andreas Färber <afaerber@suse.de> wrote:

> -    for (i = 0, cpu = first_cpu; i < s->num_cpu; i++, cpu =
> cpu->next_cpu) {
> +    i = 0;
> +    CPU_FOREACH(cpu) {
>          DeviceState *cpudev = DEVICE(cpu);
>          int ppibase = s->num_irq - 32 + i * 32;
> +
> +        if (i < s->num_cpu) {
> +            break;
> +        }
> +
>          /* physical timer; we wire it up to the non-secure timer's ID,
>           * since a real A15 always has TrustZone but QEMU doesn't.
>           */
> @@ -83,6 +89,7 @@ static int a15mp_priv_init(SysBusDevice *dev)
>          /* virtual timer */
>          qdev_connect_gpio_out(cpudev, 1,
>                                qdev_get_gpio_in(s->gic, ppibase + 27));
> +        i++;
>      }

It seems a bit ugly to have to both enumerate the CPUs
via CPU_FOREACH and update an index i simultaneously.
Isn't there any way to either say "give me the CPU pointer for
CPU i" or "give me the index i of this CPU" ?

(there are a few bits post-arm_pic-removal that could be
a little cleaner with one or the other of the above.)

thanks
-- PMM

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [Qemu-devel] [PATCH qom-cpu for-next 1/2] cpu: Use QTAILQ for CPU list
@ 2013-08-21 14:36       ` Peter Maydell
  0 siblings, 0 replies; 13+ messages in thread
From: Peter Maydell @ 2013-08-21 14:36 UTC (permalink / raw)
  To: Andreas Färber
  Cc: Anthony Liguori, Gleb Natapov, kvm, Riku Voipio, Alexander Graf,
	QEMU Developers, qemu-ppc, Paul Brook, Scott Wood, Paolo Bonzini,
	Luiz Capitulino, Aurelien Jarno

On 21 August 2013 15:12, Andreas Färber <afaerber@suse.de> wrote:

> -    for (i = 0, cpu = first_cpu; i < s->num_cpu; i++, cpu =
> cpu->next_cpu) {
> +    i = 0;
> +    CPU_FOREACH(cpu) {
>          DeviceState *cpudev = DEVICE(cpu);
>          int ppibase = s->num_irq - 32 + i * 32;
> +
> +        if (i < s->num_cpu) {
> +            break;
> +        }
> +
>          /* physical timer; we wire it up to the non-secure timer's ID,
>           * since a real A15 always has TrustZone but QEMU doesn't.
>           */
> @@ -83,6 +89,7 @@ static int a15mp_priv_init(SysBusDevice *dev)
>          /* virtual timer */
>          qdev_connect_gpio_out(cpudev, 1,
>                                qdev_get_gpio_in(s->gic, ppibase + 27));
> +        i++;
>      }

It seems a bit ugly to have to both enumerate the CPUs
via CPU_FOREACH and update an index i simultaneously.
Isn't there any way to either say "give me the CPU pointer for
CPU i" or "give me the index i of this CPU" ?

(there are a few bits post-arm_pic-removal that could be
a little cleaner with one or the other of the above.)

thanks
-- PMM

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [Qemu-devel] [PATCH qom-cpu for-next 1/2] cpu: Use QTAILQ for CPU list
  2013-08-21 14:36       ` Peter Maydell
@ 2013-08-21 16:32         ` Andreas Färber
  -1 siblings, 0 replies; 13+ messages in thread
From: Andreas Färber @ 2013-08-21 16:32 UTC (permalink / raw)
  To: Peter Maydell
  Cc: QEMU Developers, Anthony Liguori, kvm, Gleb Natapov, Riku Voipio,
	Alexander Graf, Luiz Capitulino, qemu-ppc, Paul Brook, Scott Wood,
	Paolo Bonzini, Aurelien Jarno

Am 21.08.2013 16:36, schrieb Peter Maydell:
> On 21 August 2013 15:12, Andreas Färber <afaerber@suse.de> wrote:
> 
>> -    for (i = 0, cpu = first_cpu; i < s->num_cpu; i++, cpu =
>> cpu->next_cpu) {
>> +    i = 0;
>> +    CPU_FOREACH(cpu) {
>>          DeviceState *cpudev = DEVICE(cpu);
>>          int ppibase = s->num_irq - 32 + i * 32;
>> +
>> +        if (i < s->num_cpu) {
>> +            break;
>> +        }
>> +
>>          /* physical timer; we wire it up to the non-secure timer's ID,
>>           * since a real A15 always has TrustZone but QEMU doesn't.
>>           */
>> @@ -83,6 +89,7 @@ static int a15mp_priv_init(SysBusDevice *dev)
>>          /* virtual timer */
>>          qdev_connect_gpio_out(cpudev, 1,
>>                                qdev_get_gpio_in(s->gic, ppibase + 27));
>> +        i++;
>>      }
> 
> It seems a bit ugly to have to both enumerate the CPUs
> via CPU_FOREACH and update an index i simultaneously.

Same for the original code. :)

> Isn't there any way to either say "give me the CPU pointer for
> CPU i" or "give me the index i of this CPU" ?

There is:

diff --git a/hw/cpu/a15mpcore.c b/hw/cpu/a15mpcore.c
index 9d0e27e..1263b12 100644
--- a/hw/cpu/a15mpcore.c
+++ b/hw/cpu/a15mpcore.c
@@ -50,7 +50,6 @@ static int a15mp_priv_init(SysBusDevice *dev)
     SysBusDevice *busdev;
     const char *gictype = "arm_gic";
     int i;
-    CPUState *cpu;

     if (kvm_irqchip_in_kernel()) {
         gictype = "kvm-arm-gic";
@@ -72,15 +71,10 @@ static int a15mp_priv_init(SysBusDevice *dev)
     /* Wire the outputs from each CPU's generic timer to the
      * appropriate GIC PPI inputs
      */
-    i = 0;
-    CPU_FOREACH(cpu) {
-        DeviceState *cpudev = DEVICE(cpu);
+    for (i = 0; i < s->num_cpu; i++) {
+        DeviceState *cpudev = DEVICE(qemu_get_cpu(i));
         int ppibase = s->num_irq - 32 + i * 32;

-        if (i < s->num_cpu) {
-            break;
-        }
-
         /* physical timer; we wire it up to the non-secure timer's ID,
          * since a real A15 always has TrustZone but QEMU doesn't.
          */
@@ -89,7 +83,6 @@ static int a15mp_priv_init(SysBusDevice *dev)
         /* virtual timer */
         qdev_connect_gpio_out(cpudev, 1,
                               qdev_get_gpio_in(s->gic, ppibase + 27));
-        i++;
     }

     /* Memory map (addresses are offsets from PERIPHBASE):


-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

^ permalink raw reply related	[flat|nested] 13+ messages in thread

* Re: [Qemu-devel] [PATCH qom-cpu for-next 1/2] cpu: Use QTAILQ for CPU list
@ 2013-08-21 16:32         ` Andreas Färber
  0 siblings, 0 replies; 13+ messages in thread
From: Andreas Färber @ 2013-08-21 16:32 UTC (permalink / raw)
  To: Peter Maydell
  Cc: Anthony Liguori, Gleb Natapov, kvm, Riku Voipio, Alexander Graf,
	QEMU Developers, qemu-ppc, Paul Brook, Scott Wood, Paolo Bonzini,
	Luiz Capitulino, Aurelien Jarno

Am 21.08.2013 16:36, schrieb Peter Maydell:
> On 21 August 2013 15:12, Andreas Färber <afaerber@suse.de> wrote:
> 
>> -    for (i = 0, cpu = first_cpu; i < s->num_cpu; i++, cpu =
>> cpu->next_cpu) {
>> +    i = 0;
>> +    CPU_FOREACH(cpu) {
>>          DeviceState *cpudev = DEVICE(cpu);
>>          int ppibase = s->num_irq - 32 + i * 32;
>> +
>> +        if (i < s->num_cpu) {
>> +            break;
>> +        }
>> +
>>          /* physical timer; we wire it up to the non-secure timer's ID,
>>           * since a real A15 always has TrustZone but QEMU doesn't.
>>           */
>> @@ -83,6 +89,7 @@ static int a15mp_priv_init(SysBusDevice *dev)
>>          /* virtual timer */
>>          qdev_connect_gpio_out(cpudev, 1,
>>                                qdev_get_gpio_in(s->gic, ppibase + 27));
>> +        i++;
>>      }
> 
> It seems a bit ugly to have to both enumerate the CPUs
> via CPU_FOREACH and update an index i simultaneously.

Same for the original code. :)

> Isn't there any way to either say "give me the CPU pointer for
> CPU i" or "give me the index i of this CPU" ?

There is:

diff --git a/hw/cpu/a15mpcore.c b/hw/cpu/a15mpcore.c
index 9d0e27e..1263b12 100644
--- a/hw/cpu/a15mpcore.c
+++ b/hw/cpu/a15mpcore.c
@@ -50,7 +50,6 @@ static int a15mp_priv_init(SysBusDevice *dev)
     SysBusDevice *busdev;
     const char *gictype = "arm_gic";
     int i;
-    CPUState *cpu;

     if (kvm_irqchip_in_kernel()) {
         gictype = "kvm-arm-gic";
@@ -72,15 +71,10 @@ static int a15mp_priv_init(SysBusDevice *dev)
     /* Wire the outputs from each CPU's generic timer to the
      * appropriate GIC PPI inputs
      */
-    i = 0;
-    CPU_FOREACH(cpu) {
-        DeviceState *cpudev = DEVICE(cpu);
+    for (i = 0; i < s->num_cpu; i++) {
+        DeviceState *cpudev = DEVICE(qemu_get_cpu(i));
         int ppibase = s->num_irq - 32 + i * 32;

-        if (i < s->num_cpu) {
-            break;
-        }
-
         /* physical timer; we wire it up to the non-secure timer's ID,
          * since a real A15 always has TrustZone but QEMU doesn't.
          */
@@ -89,7 +83,6 @@ static int a15mp_priv_init(SysBusDevice *dev)
         /* virtual timer */
         qdev_connect_gpio_out(cpudev, 1,
                               qdev_get_gpio_in(s->gic, ppibase + 27));
-        i++;
     }

     /* Memory map (addresses are offsets from PERIPHBASE):


-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

^ permalink raw reply related	[flat|nested] 13+ messages in thread

* [Qemu-devel] [RFC qom-cpu for-next 2/2] cpu: Replace qemu_for_each_cpu()
  2013-07-30 16:55 [Qemu-devel] [PATCH qom-cpu for-next 0/2] QOM CPUState, part 12: CPU loops, revisited Andreas Färber
  2013-07-30 16:55   ` [Qemu-devel] " Andreas Färber
@ 2013-07-30 16:55 ` Andreas Färber
  2013-07-30 18:30   ` Michael S. Tsirkin
  2013-08-14 11:49 ` [Qemu-devel] [PATCH qom-cpu for-next 0/2] QOM CPUState, part 12: CPU loops, revisited Andreas Färber
  2 siblings, 1 reply; 13+ messages in thread
From: Andreas Färber @ 2013-07-30 16:55 UTC (permalink / raw)
  To: qemu-devel; +Cc: Andreas Färber, Michael S. Tsirkin

It was introduced to loop over CPUs from target-independent code, but
since commit 182735efaf956ccab50b6d74a4fed163e0f35660 target-independent
CPUState is used.

A loop can be considered more efficient than function calls in a loop,
and CPU_FOREACH() hides implementation details just as well, so use that
instead.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
---
 arch_init.c       | 11 +++++------
 cpus.c            | 11 ++++-------
 exec.c            |  9 ---------
 hw/acpi/piix4.c   | 20 +++++++++-----------
 include/qom/cpu.h |  9 ---------
 qom/cpu.c         | 30 +++++++++---------------------
 6 files changed, 27 insertions(+), 63 deletions(-)

diff --git a/arch_init.c b/arch_init.c
index 68a7ab7..148f76e 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -1195,15 +1195,14 @@ static void mig_sleep_cpu(void *opq)
    much time in the VM. The migration thread will try to catchup.
    Workload will experience a performance drop.
 */
-static void mig_throttle_cpu_down(CPUState *cpu, void *data)
-{
-    async_run_on_cpu(cpu, mig_sleep_cpu, NULL);
-}
-
 static void mig_throttle_guest_down(void)
 {
+    CPUState *cpu;
+
     qemu_mutex_lock_iothread();
-    qemu_for_each_cpu(mig_throttle_cpu_down, NULL);
+    CPU_FOREACH(cpu) {
+        async_run_on_cpu(cpu, mig_sleep_cpu, NULL);
+    }
     qemu_mutex_unlock_iothread();
 }
 
diff --git a/cpus.c b/cpus.c
index 1e2fd8a..c1d0f18 100644
--- a/cpus.c
+++ b/cpus.c
@@ -837,12 +837,6 @@ static void *qemu_dummy_cpu_thread_fn(void *arg)
 
 static void tcg_exec_all(void);
 
-static void tcg_signal_cpu_creation(CPUState *cpu, void *data)
-{
-    cpu->thread_id = qemu_get_thread_id();
-    cpu->created = true;
-}
-
 static void *qemu_tcg_cpu_thread_fn(void *arg)
 {
     CPUState *cpu = arg;
@@ -851,7 +845,10 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
     qemu_thread_get_self(cpu->thread);
 
     qemu_mutex_lock(&qemu_global_mutex);
-    qemu_for_each_cpu(tcg_signal_cpu_creation, NULL);
+    CPU_FOREACH(cpu) {
+        cpu->thread_id = qemu_get_thread_id();
+        cpu->created = true;
+    }
     qemu_cond_signal(&qemu_cpu_cond);
 
     /* wait for initial kick-off after machine start */
diff --git a/exec.c b/exec.c
index 4ee61a6..7d90119 100644
--- a/exec.c
+++ b/exec.c
@@ -362,15 +362,6 @@ CPUState *qemu_get_cpu(int index)
     return NULL;
 }
 
-void qemu_for_each_cpu(void (*func)(CPUState *cpu, void *data), void *data)
-{
-    CPUState *cpu;
-
-    CPU_FOREACH(cpu) {
-        func(cpu, data);
-    }
-}
-
 void cpu_exec_init(CPUArchState *env)
 {
     CPUState *cpu = ENV_GET_CPU(env);
diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
index c885690..12e40b0 100644
--- a/hw/acpi/piix4.c
+++ b/hw/acpi/piix4.c
@@ -667,22 +667,14 @@ static void piix4_cpu_added_req(Notifier *n, void *opaque)
     piix4_cpu_hotplug_req(s, CPU(opaque), PLUG);
 }
 
-static void piix4_init_cpu_status(CPUState *cpu, void *data)
-{
-    CPUStatus *g = (CPUStatus *)data;
-    CPUClass *k = CPU_GET_CLASS(cpu);
-    int64_t id = k->get_arch_id(cpu);
-
-    g_assert((id / 8) < PIIX4_PROC_LEN);
-    g->sts[id / 8] |= (1 << (id % 8));
-}
-
 static int piix4_device_hotplug(DeviceState *qdev, PCIDevice *dev,
                                 PCIHotplugState state);
 
 static void piix4_acpi_system_hot_add_init(MemoryRegion *parent,
                                            PCIBus *bus, PIIX4PMState *s)
 {
+    CPUState *cpu;
+
     memory_region_init_io(&s->io_gpe, OBJECT(s), &piix4_gpe_ops, s,
                           "acpi-gpe0", GPE_LEN);
     memory_region_add_subregion(parent, GPE_BASE, &s->io_gpe);
@@ -693,7 +685,13 @@ static void piix4_acpi_system_hot_add_init(MemoryRegion *parent,
                                 &s->io_pci);
     pci_bus_hotplug(bus, piix4_device_hotplug, DEVICE(s));
 
-    qemu_for_each_cpu(piix4_init_cpu_status, &s->gpe_cpu);
+    CPU_FOREACH(cpu) {
+        CPUClass *cc = CPU_GET_CLASS(cpu);
+        int64_t id = cc->get_arch_id(cpu);
+
+        g_assert((id / 8) < PIIX4_PROC_LEN);
+        s->gpe_cpu.sts[id / 8] |= (1 << (id % 8));
+    }
     memory_region_init_io(&s->io_cpu, OBJECT(s), &cpu_hotplug_ops, s,
                           "acpi-cpu-hotplug", PIIX4_PROC_LEN);
     memory_region_add_subregion(parent, PIIX4_PROC_BASE, &s->io_cpu);
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index 6d052ee..3cc28b5 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -401,15 +401,6 @@ void run_on_cpu(CPUState *cpu, void (*func)(void *data), void *data);
 void async_run_on_cpu(CPUState *cpu, void (*func)(void *data), void *data);
 
 /**
- * qemu_for_each_cpu:
- * @func: The function to be executed.
- * @data: Data to pass to the function.
- *
- * Executes @func for each CPU.
- */
-void qemu_for_each_cpu(void (*func)(CPUState *cpu, void *data), void *data);
-
-/**
  * qemu_get_cpu:
  * @index: The CPUState@cpu_index value of the CPU to obtain.
  *
diff --git a/qom/cpu.c b/qom/cpu.c
index aa95108..ecade59 100644
--- a/qom/cpu.c
+++ b/qom/cpu.c
@@ -25,30 +25,18 @@
 #include "qemu/log.h"
 #include "sysemu/sysemu.h"
 
-typedef struct CPUExistsArgs {
-    int64_t id;
-    bool found;
-} CPUExistsArgs;
-
-static void cpu_exist_cb(CPUState *cpu, void *data)
-{
-    CPUClass *klass = CPU_GET_CLASS(cpu);
-    CPUExistsArgs *arg = data;
-
-    if (klass->get_arch_id(cpu) == arg->id) {
-        arg->found = true;
-    }
-}
-
 bool cpu_exists(int64_t id)
 {
-    CPUExistsArgs data = {
-        .id = id,
-        .found = false,
-    };
+    CPUState *cpu;
+
+    CPU_FOREACH(cpu) {
+        CPUClass *cc = CPU_GET_CLASS(cpu);
 
-    qemu_for_each_cpu(cpu_exist_cb, &data);
-    return data.found;
+        if (cc->get_arch_id(cpu) == id) {
+            return true;
+        }
+    }
+    return false;
 }
 
 bool cpu_paging_enabled(const CPUState *cpu)
-- 
1.8.1.4

^ permalink raw reply related	[flat|nested] 13+ messages in thread

* Re: [Qemu-devel] [RFC qom-cpu for-next 2/2] cpu: Replace qemu_for_each_cpu()
  2013-07-30 16:55 ` [Qemu-devel] [RFC qom-cpu for-next 2/2] cpu: Replace qemu_for_each_cpu() Andreas Färber
@ 2013-07-30 18:30   ` Michael S. Tsirkin
  0 siblings, 0 replies; 13+ messages in thread
From: Michael S. Tsirkin @ 2013-07-30 18:30 UTC (permalink / raw)
  To: Andreas Färber; +Cc: qemu-devel

On Tue, Jul 30, 2013 at 06:55:59PM +0200, Andreas Färber wrote:
> It was introduced to loop over CPUs from target-independent code, but
> since commit 182735efaf956ccab50b6d74a4fed163e0f35660 target-independent
> CPUState is used.
> 
> A loop can be considered more efficient than function calls in a loop,
> and CPU_FOREACH() hides implementation details just as well, so use that
> instead.
> 
> Suggested-by: Markus Armbruster <armbru@redhat.com>
> Signed-off-by: Andreas Färber <afaerber@suse.de>

Efficiency is unlikely to be stellar seeing as there
are tons of string matching going on in QOM.

But I don't think it matters in any of this code, so

Acked-by: Michael S. Tsirkin <mst@redhat.com>


> ---
>  arch_init.c       | 11 +++++------
>  cpus.c            | 11 ++++-------
>  exec.c            |  9 ---------
>  hw/acpi/piix4.c   | 20 +++++++++-----------
>  include/qom/cpu.h |  9 ---------
>  qom/cpu.c         | 30 +++++++++---------------------
>  6 files changed, 27 insertions(+), 63 deletions(-)
> 
> diff --git a/arch_init.c b/arch_init.c
> index 68a7ab7..148f76e 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -1195,15 +1195,14 @@ static void mig_sleep_cpu(void *opq)
>     much time in the VM. The migration thread will try to catchup.
>     Workload will experience a performance drop.
>  */
> -static void mig_throttle_cpu_down(CPUState *cpu, void *data)
> -{
> -    async_run_on_cpu(cpu, mig_sleep_cpu, NULL);
> -}
> -
>  static void mig_throttle_guest_down(void)
>  {
> +    CPUState *cpu;
> +
>      qemu_mutex_lock_iothread();
> -    qemu_for_each_cpu(mig_throttle_cpu_down, NULL);
> +    CPU_FOREACH(cpu) {
> +        async_run_on_cpu(cpu, mig_sleep_cpu, NULL);
> +    }
>      qemu_mutex_unlock_iothread();
>  }
>  
> diff --git a/cpus.c b/cpus.c
> index 1e2fd8a..c1d0f18 100644
> --- a/cpus.c
> +++ b/cpus.c
> @@ -837,12 +837,6 @@ static void *qemu_dummy_cpu_thread_fn(void *arg)
>  
>  static void tcg_exec_all(void);
>  
> -static void tcg_signal_cpu_creation(CPUState *cpu, void *data)
> -{
> -    cpu->thread_id = qemu_get_thread_id();
> -    cpu->created = true;
> -}
> -
>  static void *qemu_tcg_cpu_thread_fn(void *arg)
>  {
>      CPUState *cpu = arg;
> @@ -851,7 +845,10 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
>      qemu_thread_get_self(cpu->thread);
>  
>      qemu_mutex_lock(&qemu_global_mutex);
> -    qemu_for_each_cpu(tcg_signal_cpu_creation, NULL);
> +    CPU_FOREACH(cpu) {
> +        cpu->thread_id = qemu_get_thread_id();
> +        cpu->created = true;
> +    }
>      qemu_cond_signal(&qemu_cpu_cond);
>  
>      /* wait for initial kick-off after machine start */
> diff --git a/exec.c b/exec.c
> index 4ee61a6..7d90119 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -362,15 +362,6 @@ CPUState *qemu_get_cpu(int index)
>      return NULL;
>  }
>  
> -void qemu_for_each_cpu(void (*func)(CPUState *cpu, void *data), void *data)
> -{
> -    CPUState *cpu;
> -
> -    CPU_FOREACH(cpu) {
> -        func(cpu, data);
> -    }
> -}
> -
>  void cpu_exec_init(CPUArchState *env)
>  {
>      CPUState *cpu = ENV_GET_CPU(env);
> diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
> index c885690..12e40b0 100644
> --- a/hw/acpi/piix4.c
> +++ b/hw/acpi/piix4.c
> @@ -667,22 +667,14 @@ static void piix4_cpu_added_req(Notifier *n, void *opaque)
>      piix4_cpu_hotplug_req(s, CPU(opaque), PLUG);
>  }
>  
> -static void piix4_init_cpu_status(CPUState *cpu, void *data)
> -{
> -    CPUStatus *g = (CPUStatus *)data;
> -    CPUClass *k = CPU_GET_CLASS(cpu);
> -    int64_t id = k->get_arch_id(cpu);
> -
> -    g_assert((id / 8) < PIIX4_PROC_LEN);
> -    g->sts[id / 8] |= (1 << (id % 8));
> -}
> -
>  static int piix4_device_hotplug(DeviceState *qdev, PCIDevice *dev,
>                                  PCIHotplugState state);
>  
>  static void piix4_acpi_system_hot_add_init(MemoryRegion *parent,
>                                             PCIBus *bus, PIIX4PMState *s)
>  {
> +    CPUState *cpu;
> +
>      memory_region_init_io(&s->io_gpe, OBJECT(s), &piix4_gpe_ops, s,
>                            "acpi-gpe0", GPE_LEN);
>      memory_region_add_subregion(parent, GPE_BASE, &s->io_gpe);
> @@ -693,7 +685,13 @@ static void piix4_acpi_system_hot_add_init(MemoryRegion *parent,
>                                  &s->io_pci);
>      pci_bus_hotplug(bus, piix4_device_hotplug, DEVICE(s));
>  
> -    qemu_for_each_cpu(piix4_init_cpu_status, &s->gpe_cpu);
> +    CPU_FOREACH(cpu) {
> +        CPUClass *cc = CPU_GET_CLASS(cpu);
> +        int64_t id = cc->get_arch_id(cpu);
> +
> +        g_assert((id / 8) < PIIX4_PROC_LEN);
> +        s->gpe_cpu.sts[id / 8] |= (1 << (id % 8));
> +    }
>      memory_region_init_io(&s->io_cpu, OBJECT(s), &cpu_hotplug_ops, s,
>                            "acpi-cpu-hotplug", PIIX4_PROC_LEN);
>      memory_region_add_subregion(parent, PIIX4_PROC_BASE, &s->io_cpu);
> diff --git a/include/qom/cpu.h b/include/qom/cpu.h
> index 6d052ee..3cc28b5 100644
> --- a/include/qom/cpu.h
> +++ b/include/qom/cpu.h
> @@ -401,15 +401,6 @@ void run_on_cpu(CPUState *cpu, void (*func)(void *data), void *data);
>  void async_run_on_cpu(CPUState *cpu, void (*func)(void *data), void *data);
>  
>  /**
> - * qemu_for_each_cpu:
> - * @func: The function to be executed.
> - * @data: Data to pass to the function.
> - *
> - * Executes @func for each CPU.
> - */
> -void qemu_for_each_cpu(void (*func)(CPUState *cpu, void *data), void *data);
> -
> -/**
>   * qemu_get_cpu:
>   * @index: The CPUState@cpu_index value of the CPU to obtain.
>   *
> diff --git a/qom/cpu.c b/qom/cpu.c
> index aa95108..ecade59 100644
> --- a/qom/cpu.c
> +++ b/qom/cpu.c
> @@ -25,30 +25,18 @@
>  #include "qemu/log.h"
>  #include "sysemu/sysemu.h"
>  
> -typedef struct CPUExistsArgs {
> -    int64_t id;
> -    bool found;
> -} CPUExistsArgs;
> -
> -static void cpu_exist_cb(CPUState *cpu, void *data)
> -{
> -    CPUClass *klass = CPU_GET_CLASS(cpu);
> -    CPUExistsArgs *arg = data;
> -
> -    if (klass->get_arch_id(cpu) == arg->id) {
> -        arg->found = true;
> -    }
> -}
> -
>  bool cpu_exists(int64_t id)
>  {
> -    CPUExistsArgs data = {
> -        .id = id,
> -        .found = false,
> -    };
> +    CPUState *cpu;
> +
> +    CPU_FOREACH(cpu) {
> +        CPUClass *cc = CPU_GET_CLASS(cpu);
>  
> -    qemu_for_each_cpu(cpu_exist_cb, &data);
> -    return data.found;
> +        if (cc->get_arch_id(cpu) == id) {
> +            return true;
> +        }
> +    }
> +    return false;
>  }
>  
>  bool cpu_paging_enabled(const CPUState *cpu)
> -- 
> 1.8.1.4

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [Qemu-devel] [PATCH qom-cpu for-next 0/2] QOM CPUState, part 12: CPU loops, revisited
  2013-07-30 16:55 [Qemu-devel] [PATCH qom-cpu for-next 0/2] QOM CPUState, part 12: CPU loops, revisited Andreas Färber
  2013-07-30 16:55   ` [Qemu-devel] " Andreas Färber
  2013-07-30 16:55 ` [Qemu-devel] [RFC qom-cpu for-next 2/2] cpu: Replace qemu_for_each_cpu() Andreas Färber
@ 2013-08-14 11:49 ` Andreas Färber
  2013-08-30 14:42   ` Andreas Färber
  2 siblings, 1 reply; 13+ messages in thread
From: Andreas Färber @ 2013-08-14 11:49 UTC (permalink / raw)
  To: qemu-devel
  Cc: Peter Maydell, Eduardo Habkost, Michael S. Tsirkin, Riku Voipio,
	Markus Armbruster, Alexander Graf, Blue Swirl, Anthony Liguori,
	Paolo Bonzini, Igor Mammedov, Aurélien Jarno

Am 30.07.2013 18:55, schrieb Andreas Färber:
> Hello everyone,
> 
> A short CPUState series for a change: This mini-series replaces our home-grown
> CPU list (first_cpu global and CPUState::next_cpu) with a QTAILQ.
> 
> To avoid repeated QTAILQ_FOREACH(foo, cpus, node) I am proposing a wrapper
> CPU_FOREACH(foo) to hide the implementation details, as requested by mst,
> while keeping inline loops, as requested by Markus.
> 
> The bulk of patch 1 is mechanical for/while loop conversions, except for:
> exec.c: QTAILQ_INSERT_TAIL()
> linux-user/syscall.c: QTAILQ_REMOVE() -- untested!

Ping! The 1.7 merge window is approaching and Michael has ack'ed
adopting the macros introduced in patch 1/2, but that patch has no
review or test reports yet. Riku? Peter? Alex?

Latest rebased version on qom-cpu-12 branch.

Regards,
Andreas

> Having such a stable API will help with vCPU hot-unplug.
> 
> Patch 2 is controversial: It drops qemu_for_each_cpu() on Markus' request.
> I'm including it as RFC to showcase what exactly those suggestions involve.
> Converting from for (cpu = ...) to CPU_FOREACH(cpu) is obviously much more
> straightforward than converting between function and loop, therefore with
> patch 1 in mind, it seems best to still use for loops, which since recently
> no longer require CPUArchState, the original trigger for qemu_for_each_cpu().
> 
> Available for testing at:
> git://github.com/afaerber/qemu-cpu.git qom-cpu-12.v1
> https://github.com/afaerber/qemu-cpu/commits/qom-cpu-12.v1
> 
> Regards,
> Andreas
> 
> From CPUState part 10 v1:
> * Instead of replacing every loop with qemu_for_each_cpu()
>   replace loops with CPU_FOREACH() macro, based on QTAILQ_FOREACH().
> 
> Cc: Markus Armbruster <armbru@redhat.com>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Cc: Anthony Liguori <anthony@codemonkey.ws>
> Cc: Blue Swirl <blauwirbel@gmail.com>
> Cc: Aurélien Jarno <aurelien@aurel32.net>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Eduardo Habkost <ehabkost@redhat.com>
> Cc: Igor Mammedov <imammedo@redhat.com>
> Cc: Riku Voipio <riku.voipio@iki.fi>
> 
> Andreas Färber (2):
>   cpu: Use QTAILQ for CPU list
>   cpu: Replace qemu_for_each_cpu()
> 
>  arch_init.c               | 11 ++++-----
>  cpus.c                    | 58 ++++++++++++++++++++---------------------------
>  cputlb.c                  |  2 +-
>  dump.c                    | 10 ++++----
>  exec.c                    | 33 ++++++++-------------------
>  gdbstub.c                 | 14 ++++++------
>  hw/acpi/piix4.c           | 20 ++++++++--------
>  hw/arm/boot.c             |  2 +-
>  hw/i386/kvm/clock.c       |  2 +-
>  hw/i386/kvmvapic.c        |  2 +-
>  hw/i386/pc.c              |  3 +--
>  hw/ppc/e500.c             |  2 +-
>  hw/ppc/ppc.c              |  2 +-
>  hw/ppc/spapr.c            |  4 ++--
>  include/qom/cpu.h         | 20 ++++++++--------
>  kvm-all.c                 |  8 +++----
>  linux-user/elfload.c      |  2 +-
>  linux-user/main.c         | 10 +++++---
>  linux-user/syscall.c      | 17 ++------------
>  memory_mapping.c          |  5 ++--
>  monitor.c                 |  2 +-
>  qom/cpu.c                 | 30 ++++++++----------------
>  target-i386/helper.c      |  3 +--
>  target-i386/misc_helper.c |  2 +-
>  target-mips/op_helper.c   | 10 ++++----
>  target-ppc/excp_helper.c  |  2 +-
>  translate-all.c           |  4 ++--
>  27 files changed, 113 insertions(+), 167 deletions(-)
> 


-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [Qemu-devel] [PATCH qom-cpu for-next 0/2] QOM CPUState, part 12: CPU loops, revisited
  2013-08-14 11:49 ` [Qemu-devel] [PATCH qom-cpu for-next 0/2] QOM CPUState, part 12: CPU loops, revisited Andreas Färber
@ 2013-08-30 14:42   ` Andreas Färber
  0 siblings, 0 replies; 13+ messages in thread
From: Andreas Färber @ 2013-08-30 14:42 UTC (permalink / raw)
  To: qemu-devel
  Cc: Peter Maydell, Eduardo Habkost, Michael S. Tsirkin, Riku Voipio,
	Alexander Graf, Markus Armbruster, Blue Swirl, Anthony Liguori,
	Igor Mammedov, Paolo Bonzini, Aurélien Jarno

Am 14.08.2013 13:49, schrieb Andreas Färber:
> Am 30.07.2013 18:55, schrieb Andreas Färber:
>> Hello everyone,
>>
>> A short CPUState series for a change: This mini-series replaces our home-grown
>> CPU list (first_cpu global and CPUState::next_cpu) with a QTAILQ.
>>
>> To avoid repeated QTAILQ_FOREACH(foo, cpus, node) I am proposing a wrapper
>> CPU_FOREACH(foo) to hide the implementation details, as requested by mst,
>> while keeping inline loops, as requested by Markus.
>>
>> The bulk of patch 1 is mechanical for/while loop conversions, except for:
>> exec.c: QTAILQ_INSERT_TAIL()
>> linux-user/syscall.c: QTAILQ_REMOVE() -- untested!
> 
> Ping! The 1.7 merge window is approaching and Michael has ack'ed
> adopting the macros introduced in patch 1/2, but that patch has no
> review or test reports yet. Riku? Peter? Alex?

Applied to qom-cpu:
https://github.com/afaerber/qemu-cpu/commits/qom-cpu

Andreas

> 
> Latest rebased version on qom-cpu-12 branch.
> 
> Regards,
> Andreas
> 
>> Having such a stable API will help with vCPU hot-unplug.
>>
>> Patch 2 is controversial: It drops qemu_for_each_cpu() on Markus' request.
>> I'm including it as RFC to showcase what exactly those suggestions involve.
>> Converting from for (cpu = ...) to CPU_FOREACH(cpu) is obviously much more
>> straightforward than converting between function and loop, therefore with
>> patch 1 in mind, it seems best to still use for loops, which since recently
>> no longer require CPUArchState, the original trigger for qemu_for_each_cpu().
>>
>> Available for testing at:
>> git://github.com/afaerber/qemu-cpu.git qom-cpu-12.v1
>> https://github.com/afaerber/qemu-cpu/commits/qom-cpu-12.v1
>>
>> Regards,
>> Andreas
>>
>> From CPUState part 10 v1:
>> * Instead of replacing every loop with qemu_for_each_cpu()
>>   replace loops with CPU_FOREACH() macro, based on QTAILQ_FOREACH().
>>
>> Cc: Markus Armbruster <armbru@redhat.com>
>> Cc: Michael S. Tsirkin <mst@redhat.com>
>> Cc: Anthony Liguori <anthony@codemonkey.ws>
>> Cc: Blue Swirl <blauwirbel@gmail.com>
>> Cc: Aurélien Jarno <aurelien@aurel32.net>
>> Cc: Paolo Bonzini <pbonzini@redhat.com>
>> Cc: Eduardo Habkost <ehabkost@redhat.com>
>> Cc: Igor Mammedov <imammedo@redhat.com>
>> Cc: Riku Voipio <riku.voipio@iki.fi>
>>
>> Andreas Färber (2):
>>   cpu: Use QTAILQ for CPU list
>>   cpu: Replace qemu_for_each_cpu()
>>
>>  arch_init.c               | 11 ++++-----
>>  cpus.c                    | 58 ++++++++++++++++++++---------------------------
>>  cputlb.c                  |  2 +-
>>  dump.c                    | 10 ++++----
>>  exec.c                    | 33 ++++++++-------------------
>>  gdbstub.c                 | 14 ++++++------
>>  hw/acpi/piix4.c           | 20 ++++++++--------
>>  hw/arm/boot.c             |  2 +-
>>  hw/i386/kvm/clock.c       |  2 +-
>>  hw/i386/kvmvapic.c        |  2 +-
>>  hw/i386/pc.c              |  3 +--
>>  hw/ppc/e500.c             |  2 +-
>>  hw/ppc/ppc.c              |  2 +-
>>  hw/ppc/spapr.c            |  4 ++--
>>  include/qom/cpu.h         | 20 ++++++++--------
>>  kvm-all.c                 |  8 +++----
>>  linux-user/elfload.c      |  2 +-
>>  linux-user/main.c         | 10 +++++---
>>  linux-user/syscall.c      | 17 ++------------
>>  memory_mapping.c          |  5 ++--
>>  monitor.c                 |  2 +-
>>  qom/cpu.c                 | 30 ++++++++----------------
>>  target-i386/helper.c      |  3 +--
>>  target-i386/misc_helper.c |  2 +-
>>  target-mips/op_helper.c   | 10 ++++----
>>  target-ppc/excp_helper.c  |  2 +-
>>  translate-all.c           |  4 ++--
>>  27 files changed, 113 insertions(+), 167 deletions(-)
>>
> 
> 


-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

^ permalink raw reply	[flat|nested] 13+ messages in thread

end of thread, other threads:[~2013-08-30 14:42 UTC | newest]

Thread overview: 13+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-07-30 16:55 [Qemu-devel] [PATCH qom-cpu for-next 0/2] QOM CPUState, part 12: CPU loops, revisited Andreas Färber
2013-07-30 16:55 ` [PATCH qom-cpu for-next 1/2] cpu: Use QTAILQ for CPU list Andreas Färber
2013-07-30 16:55   ` [Qemu-devel] " Andreas Färber
2013-08-21 14:12   ` Andreas Färber
2013-08-21 14:12     ` Andreas Färber
2013-08-21 14:36     ` Peter Maydell
2013-08-21 14:36       ` Peter Maydell
2013-08-21 16:32       ` Andreas Färber
2013-08-21 16:32         ` Andreas Färber
2013-07-30 16:55 ` [Qemu-devel] [RFC qom-cpu for-next 2/2] cpu: Replace qemu_for_each_cpu() Andreas Färber
2013-07-30 18:30   ` Michael S. Tsirkin
2013-08-14 11:49 ` [Qemu-devel] [PATCH qom-cpu for-next 0/2] QOM CPUState, part 12: CPU loops, revisited Andreas Färber
2013-08-30 14:42   ` Andreas Färber

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