accel: replace struct CpusAccel with AccelOpsClass

This will allow us to centralize the registration of
the cpus.c module accelerator operations (in accel/accel-softmmu.c),
and trigger it automatically using object hierarchy lookup from the
new accel_init_interfaces() initialization step, depending just on
which accelerators are available in the code.

Rename all tcg-cpus.c, kvm-cpus.c, etc to tcg-accel-ops.c,
kvm-accel-ops.c, etc, matching the object type names.

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Message-Id: <20210204163931.7358-18-cfontana@suse.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 298 insertions, 0 deletions

diff --git a/accel/tcg/tcg-accel-ops-rr.c b/accel/tcg/tcg-accel-ops-rr.c
new file mode 100644
index 0000000000..4a66055e0d
--- /dev/null
+++ b/accel/tcg/tcg-accel-ops-rr.c
@@ -0,0 +1,298 @@
+/*
+ * QEMU TCG Single Threaded vCPUs implementation
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ * Copyright (c) 2014 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "sysemu/tcg.h"
+#include "sysemu/replay.h"
+#include "qemu/main-loop.h"
+#include "qemu/guest-random.h"
+#include "exec/exec-all.h"
+#include "hw/boards.h"
+
+#include "tcg-accel-ops.h"
+#include "tcg-accel-ops-rr.h"
+#include "tcg-accel-ops-icount.h"
+
+/* Kick all RR vCPUs */
+void rr_kick_vcpu_thread(CPUState *unused)
+{
+    CPUState *cpu;
+
+    CPU_FOREACH(cpu) {
+        cpu_exit(cpu);
+    };
+}
+
+/*
+ * TCG vCPU kick timer
+ *
+ * The kick timer is responsible for moving single threaded vCPU
+ * emulation on to the next vCPU. If more than one vCPU is running a
+ * timer event with force a cpu->exit so the next vCPU can get
+ * scheduled.
+ *
+ * The timer is removed if all vCPUs are idle and restarted again once
+ * idleness is complete.
+ */
+
+static QEMUTimer *rr_kick_vcpu_timer;
+static CPUState *rr_current_cpu;
+
+#define TCG_KICK_PERIOD (NANOSECONDS_PER_SECOND / 10)
+
+static inline int64_t rr_next_kick_time(void)
+{
+    return qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + TCG_KICK_PERIOD;
+}
+
+/* Kick the currently round-robin scheduled vCPU to next */
+static void rr_kick_next_cpu(void)
+{
+    CPUState *cpu;
+    do {
+        cpu = qatomic_mb_read(&rr_current_cpu);
+        if (cpu) {
+            cpu_exit(cpu);
+        }
+    } while (cpu != qatomic_mb_read(&rr_current_cpu));
+}
+
+static void rr_kick_thread(void *opaque)
+{
+    timer_mod(rr_kick_vcpu_timer, rr_next_kick_time());
+    rr_kick_next_cpu();
+}
+
+static void rr_start_kick_timer(void)
+{
+    if (!rr_kick_vcpu_timer && CPU_NEXT(first_cpu)) {
+        rr_kick_vcpu_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
+                                           rr_kick_thread, NULL);
+    }
+    if (rr_kick_vcpu_timer && !timer_pending(rr_kick_vcpu_timer)) {
+        timer_mod(rr_kick_vcpu_timer, rr_next_kick_time());
+    }
+}
+
+static void rr_stop_kick_timer(void)
+{
+    if (rr_kick_vcpu_timer && timer_pending(rr_kick_vcpu_timer)) {
+        timer_del(rr_kick_vcpu_timer);
+    }
+}
+
+static void rr_wait_io_event(void)
+{
+    CPUState *cpu;
+
+    while (all_cpu_threads_idle()) {
+        rr_stop_kick_timer();
+        qemu_cond_wait_iothread(first_cpu->halt_cond);
+    }
+
+    rr_start_kick_timer();
+
+    CPU_FOREACH(cpu) {
+        qemu_wait_io_event_common(cpu);
+    }
+}
+
+/*
+ * Destroy any remaining vCPUs which have been unplugged and have
+ * finished running
+ */
+static void rr_deal_with_unplugged_cpus(void)
+{
+    CPUState *cpu;
+
+    CPU_FOREACH(cpu) {
+        if (cpu->unplug && !cpu_can_run(cpu)) {
+            tcg_cpus_destroy(cpu);
+            break;
+        }
+    }
+}
+
+/*
+ * In the single-threaded case each vCPU is simulated in turn. If
+ * there is more than a single vCPU we create a simple timer to kick
+ * the vCPU and ensure we don't get stuck in a tight loop in one vCPU.
+ * This is done explicitly rather than relying on side-effects
+ * elsewhere.
+ */
+
+static void *rr_cpu_thread_fn(void *arg)
+{
+    CPUState *cpu = arg;
+
+    assert(tcg_enabled());
+    rcu_register_thread();
+    tcg_register_thread();
+
+    qemu_mutex_lock_iothread();
+    qemu_thread_get_self(cpu->thread);
+
+    cpu->thread_id = qemu_get_thread_id();
+    cpu->can_do_io = 1;
+    cpu_thread_signal_created(cpu);
+    qemu_guest_random_seed_thread_part2(cpu->random_seed);
+
+    /* wait for initial kick-off after machine start */
+    while (first_cpu->stopped) {
+        qemu_cond_wait_iothread(first_cpu->halt_cond);
+
+        /* process any pending work */
+        CPU_FOREACH(cpu) {
+            current_cpu = cpu;
+            qemu_wait_io_event_common(cpu);
+        }
+    }
+
+    rr_start_kick_timer();
+
+    cpu = first_cpu;
+
+    /* process any pending work */
+    cpu->exit_request = 1;
+
+    while (1) {
+        qemu_mutex_unlock_iothread();
+        replay_mutex_lock();
+        qemu_mutex_lock_iothread();
+
+        if (icount_enabled()) {
+            /* Account partial waits to QEMU_CLOCK_VIRTUAL.  */
+            icount_account_warp_timer();
+            /*
+             * Run the timers here.  This is much more efficient than
+             * waking up the I/O thread and waiting for completion.
+             */
+            icount_handle_deadline();
+        }
+
+        replay_mutex_unlock();
+
+        if (!cpu) {
+            cpu = first_cpu;
+        }
+
+        while (cpu && cpu_work_list_empty(cpu) && !cpu->exit_request) {
+
+            qatomic_mb_set(&rr_current_cpu, cpu);
+            current_cpu = cpu;
+
+            qemu_clock_enable(QEMU_CLOCK_VIRTUAL,
+                              (cpu->singlestep_enabled & SSTEP_NOTIMER) == 0);
+
+            if (cpu_can_run(cpu)) {
+                int r;
+
+                qemu_mutex_unlock_iothread();
+                if (icount_enabled()) {
+                    icount_prepare_for_run(cpu);
+                }
+                r = tcg_cpus_exec(cpu);
+                if (icount_enabled()) {
+                    icount_process_data(cpu);
+                }
+                qemu_mutex_lock_iothread();
+
+                if (r == EXCP_DEBUG) {
+                    cpu_handle_guest_debug(cpu);
+                    break;
+                } else if (r == EXCP_ATOMIC) {
+                    qemu_mutex_unlock_iothread();
+                    cpu_exec_step_atomic(cpu);
+                    qemu_mutex_lock_iothread();
+                    break;
+                }
+            } else if (cpu->stop) {
+                if (cpu->unplug) {
+                    cpu = CPU_NEXT(cpu);
+                }
+                break;
+            }
+
+            cpu = CPU_NEXT(cpu);
+        } /* while (cpu && !cpu->exit_request).. */
+
+        /* Does not need qatomic_mb_set because a spurious wakeup is okay.  */
+        qatomic_set(&rr_current_cpu, NULL);
+
+        if (cpu && cpu->exit_request) {
+            qatomic_mb_set(&cpu->exit_request, 0);
+        }
+
+        if (icount_enabled() && all_cpu_threads_idle()) {
+            /*
+             * When all cpus are sleeping (e.g in WFI), to avoid a deadlock
+             * in the main_loop, wake it up in order to start the warp timer.
+             */
+            qemu_notify_event();
+        }
+
+        rr_wait_io_event();
+        rr_deal_with_unplugged_cpus();
+    }
+
+    rcu_unregister_thread();
+    return NULL;
+}
+
+void rr_start_vcpu_thread(CPUState *cpu)
+{
+    char thread_name[VCPU_THREAD_NAME_SIZE];
+    static QemuCond *single_tcg_halt_cond;
+    static QemuThread *single_tcg_cpu_thread;
+
+    g_assert(tcg_enabled());
+    parallel_cpus = false;
+
+    if (!single_tcg_cpu_thread) {
+        cpu->thread = g_malloc0(sizeof(QemuThread));
+        cpu->halt_cond = g_malloc0(sizeof(QemuCond));
+        qemu_cond_init(cpu->halt_cond);
+
+        /* share a single thread for all cpus with TCG */
+        snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "ALL CPUs/TCG");
+        qemu_thread_create(cpu->thread, thread_name,
+                           rr_cpu_thread_fn,
+                           cpu, QEMU_THREAD_JOINABLE);
+
+        single_tcg_halt_cond = cpu->halt_cond;
+        single_tcg_cpu_thread = cpu->thread;
+#ifdef _WIN32
+        cpu->hThread = qemu_thread_get_handle(cpu->thread);
+#endif
+    } else {
+        /* we share the thread */
+        cpu->thread = single_tcg_cpu_thread;
+        cpu->halt_cond = single_tcg_halt_cond;
+        cpu->thread_id = first_cpu->thread_id;
+        cpu->can_do_io = 1;
+        cpu->created = true;
+    }
+}