Re: [Qemu-devel] [PULL 13/21] apic_common: vapic_paddr synchronization fix

[Paolo Bonzini <pbonzini@redhat.com>]

Il 26/09/2014 13:18, Pavel Dovgaluk ha scritto:
>> From: Paolo Bonzini [mailto:paolo.bonzini@gmail.com] On Behalf Of Paolo Bonzini
>>
>> This patch postpones vapic_paddr initialization, which is performed
>> during migration. When vapic_paddr is synchronized within the migration
>> process, apic_common functions could operate with incorrect apic state,
>> if it hadn't loaded yet. This patch postpones the synchronization until
>> the virtual machine is started, ensuring that the whole virtual machine
>> state has been loaded.
>>
>> Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
>> Tested-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>> ---
>>  hw/i386/kvmvapic.c | 37 ++++++++++++++++++++++++++-----------
>>  1 file changed, 26 insertions(+), 11 deletions(-)
> 
> One more issue for this patch.
> 
>> -static int vapic_post_load(void *opaque, int version_id)
>> +static void kvmvapic_vm_state_change(void *opaque, int running,
>> +                                     RunState state)
>>  {
>>      VAPICROMState *s = opaque;
>>      uint8_t *zero;
>>
>> +    if (!running) {
> 
> Exitting here doesn't remove vmsentry. When we load VM state for multiple times,
> list of the handlers will be filled with garbage.

Thanks.

Paolo

>> +        return;
>> +    }
>> +
>> +    if (s->state == VAPIC_ACTIVE) {
>> +        if (smp_cpus == 1) {
>> +            run_on_cpu(first_cpu, do_vapic_enable, s);
>> +        } else {
>> +            zero = g_malloc0(s->rom_state.vapic_size);
>> +            cpu_physical_memory_write(s->vapic_paddr, zero,
>> +                                      s->rom_state.vapic_size);
>> +            g_free(zero);
>> +        }
>> +    }
>> +
>> +    qemu_del_vm_change_state_handler(s->vmsentry);
>> +}
> 
> 
> Pavel Dovgalyuk
>