cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

tcg-accel-ops-mttcg.c (4209B)

      1/*
      2 * QEMU TCG Multi Threaded vCPUs implementation
      3 *
      4 * Copyright (c) 2003-2008 Fabrice Bellard
      5 * Copyright (c) 2014 Red Hat Inc.
      6 *
      7 * Permission is hereby granted, free of charge, to any person obtaining a copy
      8 * of this software and associated documentation files (the "Software"), to deal
      9 * in the Software without restriction, including without limitation the rights
     10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     11 * copies of the Software, and to permit persons to whom the Software is
     12 * furnished to do so, subject to the following conditions:
     13 *
     14 * The above copyright notice and this permission notice shall be included in
     15 * all copies or substantial portions of the Software.
     16 *
     17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
     20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
     22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
     23 * THE SOFTWARE.
     24 */
     25
     26#include "qemu/osdep.h"
     27#include "qemu-common.h"
     28#include "sysemu/tcg.h"
     29#include "sysemu/replay.h"
     30#include "qemu/main-loop.h"
     31#include "qemu/guest-random.h"
     32#include "exec/exec-all.h"
     33#include "hw/boards.h"
     34
     35#include "tcg-accel-ops.h"
     36#include "tcg-accel-ops-mttcg.h"
     37
     38/*
     39 * In the multi-threaded case each vCPU has its own thread. The TLS
     40 * variable current_cpu can be used deep in the code to find the
     41 * current CPUState for a given thread.
     42 */
     43
     44static void *mttcg_cpu_thread_fn(void *arg)
     45{
     46    CPUState *cpu = arg;
     47
     48    assert(tcg_enabled());
     49    g_assert(!icount_enabled());
     50
     51    rcu_register_thread();
     52    tcg_register_thread();
     53
     54    qemu_mutex_lock_iothread();
     55    qemu_thread_get_self(cpu->thread);
     56
     57    cpu->thread_id = qemu_get_thread_id();
     58    cpu->can_do_io = 1;
     59    current_cpu = cpu;
     60    cpu_thread_signal_created(cpu);
     61    qemu_guest_random_seed_thread_part2(cpu->random_seed);
     62
     63    /* process any pending work */
     64    cpu->exit_request = 1;
     65
     66    do {
     67        if (cpu_can_run(cpu)) {
     68            int r;
     69            qemu_mutex_unlock_iothread();
     70            r = tcg_cpus_exec(cpu);
     71            qemu_mutex_lock_iothread();
     72            switch (r) {
     73            case EXCP_DEBUG:
     74                cpu_handle_guest_debug(cpu);
     75                break;
     76            case EXCP_HALTED:
     77                /*
     78                 * during start-up the vCPU is reset and the thread is
     79                 * kicked several times. If we don't ensure we go back
     80                 * to sleep in the halted state we won't cleanly
     81                 * start-up when the vCPU is enabled.
     82                 *
     83                 * cpu->halted should ensure we sleep in wait_io_event
     84                 */
     85                g_assert(cpu->halted);
     86                break;
     87            case EXCP_ATOMIC:
     88                qemu_mutex_unlock_iothread();
     89                cpu_exec_step_atomic(cpu);
     90                qemu_mutex_lock_iothread();
     91            default:
     92                /* Ignore everything else? */
     93                break;
     94            }
     95        }
     96
     97        qatomic_mb_set(&cpu->exit_request, 0);
     98        qemu_wait_io_event(cpu);
     99    } while (!cpu->unplug || cpu_can_run(cpu));
    100
    101    tcg_cpus_destroy(cpu);
    102    qemu_mutex_unlock_iothread();
    103    rcu_unregister_thread();
    104    return NULL;
    105}
    106
    107void mttcg_kick_vcpu_thread(CPUState *cpu)
    108{
    109    cpu_exit(cpu);
    110}
    111
    112void mttcg_start_vcpu_thread(CPUState *cpu)
    113{
    114    char thread_name[VCPU_THREAD_NAME_SIZE];
    115
    116    g_assert(tcg_enabled());
    117    tcg_cpu_init_cflags(cpu, current_machine->smp.max_cpus > 1);
    118
    119    cpu->thread = g_malloc0(sizeof(QemuThread));
    120    cpu->halt_cond = g_malloc0(sizeof(QemuCond));
    121    qemu_cond_init(cpu->halt_cond);
    122
    123    /* create a thread per vCPU with TCG (MTTCG) */
    124    snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "CPU %d/TCG",
    125             cpu->cpu_index);
    126
    127    qemu_thread_create(cpu->thread, thread_name, mttcg_cpu_thread_fn,
    128                       cpu, QEMU_THREAD_JOINABLE);
    129
    130#ifdef _WIN32
    131    cpu->hThread = qemu_thread_get_handle(cpu->thread);
    132#endif
    133}