[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 6/6] target-i386: Call cpu_exec_init() on realiz
From: |
Andreas Färber |
Subject: |
Re: [Qemu-devel] [PATCH 6/6] target-i386: Call cpu_exec_init() on realize |
Date: |
Thu, 05 Mar 2015 17:44:58 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 |
Am 05.03.2015 um 17:42 schrieb Igor Mammedov:
> On Thu, 5 Mar 2015 12:38:50 -0300
> Eduardo Habkost <address@hidden> wrote:
>
>> To allow new code to ask the CPU classes for CPU model information and
>> allow QOM properties to be queried by qmp_device_list_properties(), we
>> need to be able to safely instantiate a X86CPU object without any
>> side-effects.
>>
>> cpu_exec_init() has lots of side-effects on global QEMU state, move it
>> to realize so it will be called only if the X86CPU instance is realized.
>>
>> For reference, this is the current cpu_exec_init() code:
>>
>>> void cpu_exec_init(CPUArchState *env)
>>> {
>>> CPUState *cpu = ENV_GET_CPU(env);
>>> CPUClass *cc = CPU_GET_CLASS(cpu);
>>> CPUState *some_cpu;
>>> int cpu_index;
>>>
>>> #ifndef CONFIG_USER_ONLY
>>> cpu->as = &address_space_memory;
>>> cpu->thread_id = qemu_get_thread_id();
>>> #endif
>>
>> Those fields should be used only after actually starting the VCPU and can be
>> initialized on realize.
>>
>>>
>>> #if defined(CONFIG_USER_ONLY)
>>> cpu_list_lock();
>>> #endif
>>> cpu_index = 0;
>>> CPU_FOREACH(some_cpu) {
>>> cpu_index++;
>>> }
>>> cpu->cpu_index = cpu_index;
>>> QTAILQ_INSERT_TAIL(&cpus, cpu, node);
>>> #if defined(CONFIG_USER_ONLY)
>>> cpu_list_unlock();
>>> #endif
>>
>> The above initializes cpu_index and add the CPU to the global CPU list.
>> This affects QEMU global state and must be done only on realize.
>>
>>> if (qdev_get_vmsd(DEVICE(cpu)) == NULL) {
>>> vmstate_register(NULL, cpu_index, &vmstate_cpu_common, cpu);
>>> }
>>> #if defined(CPU_SAVE_VERSION) && !defined(CONFIG_USER_ONLY)
>>> register_savevm(NULL, "cpu", cpu_index, CPU_SAVE_VERSION,
>>> cpu_save, cpu_load, env);
>>> assert(cc->vmsd == NULL);
>>> assert(qdev_get_vmsd(DEVICE(cpu)) == NULL);
>>> #endif
>>> if (cc->vmsd != NULL) {
>>> vmstate_register(NULL, cpu_index, cc->vmsd, cpu);
>>> }
>>
>> vmstate and savevm registration also affects global QEMU state and should be
>> done only on realize.
>>
>>> }
>>
>> Signed-off-by: Eduardo Habkost <address@hidden>
>> ---
>> target-i386/cpu.c | 3 ++-
>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
>> index 400b1e0..8b76604 100644
>> --- a/target-i386/cpu.c
>> +++ b/target-i386/cpu.c
>> @@ -2758,6 +2758,8 @@ static void x86_cpu_realizefn(DeviceState *dev, Error
>> **errp)
>> static bool ht_warned;
>> static bool tcg_initialized;
>>
>> + cpu_exec_init(env);
>> +
>> if (tcg_enabled() && !tcg_initialized) {
>> tcg_initialized = 1;
>> tcg_x86_init();
>> @@ -2840,7 +2842,6 @@ static void x86_cpu_initfn(Object *obj)
>> CPUX86State *env = &cpu->env;
>>
>> cs->env_ptr = env;
>> - cpu_exec_init(env);
> looks wrong, later in this function we do
> env->cpuid_apic_id = x86_cpu_apic_id_from_index(cs->cpu_index);
> and with this patch will always yield 0
Being tackled in Eduardo's APIC series. ;)
Cheers,
Andreas
--
SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Felix Imendörffer, Jane Smithard, Jennifer Guild, Dilip Upmanyu,
Graham Norton; HRB 21284 (AG Nürnberg)
- [Qemu-devel] [PATCH 2/6] cpu: Initialize breakpoint/watchpoint lists on cpu_common_initfn(), (continued)
- [Qemu-devel] [PATCH 2/6] cpu: Initialize breakpoint/watchpoint lists on cpu_common_initfn(), Eduardo Habkost, 2015/03/05
- [Qemu-devel] [PATCH 3/6] cpu: Reorder cpu->as and cpu->thread_id initialization, Eduardo Habkost, 2015/03/05
- [Qemu-devel] [PATCH 5/6] target-i386: Move TCG initialization to realize time, Eduardo Habkost, 2015/03/05
- [Qemu-devel] [PATCH 4/6] target-i386: Rename optimize_flags_init(), Eduardo Habkost, 2015/03/05
- [Qemu-devel] [PATCH 6/6] target-i386: Call cpu_exec_init() on realize, Eduardo Habkost, 2015/03/05
- [Qemu-devel] [PATCH 1/6] cpu: No need to zero-initialize numa_node, Eduardo Habkost, 2015/03/05
- Re: [Qemu-devel] [PATCH 0/6] target-i386: Remove side-effects from X86CPU::instance_init, Eduardo Habkost, 2015/03/05