Am 12.05.2014 12:25, schrieb Peter Lieven:
> Am 12.05.2014 12:19, schrieb Juan Quintela:
>> Peter Lieven <p...@kamp.de> wrote:
>>> if a saved vm has unknown flags in the memory data qemu
>>> currently simply ignores this flag and continues which
>>> yields in an unpredictable result.
>>>
>>> this patch catches all unknown flags and
>>> aborts the loading of the vm.
>>>
>>> CC: qemu-sta...@nongnu.org
>>> Signed-off-by: Peter Lieven <p...@kamp.de>
>> .....
>>
>> Once here, shouldn't be better to do this as:
>>
>> change do {} while () for while (true) {}
>>
>>>
>>> @@ -1121,6 +1119,9 @@ static int ram_load(QEMUFile *f, void *opaque, int
>>> version_id)
>>> }
>>> } else if (flags & RAM_SAVE_FLAG_HOOK) {
>>> ram_control_load_hook(f, flags);
>>> + } else if (!(flags & RAM_SAVE_FLAG_EOS)) {
>>> + ret = -EINVAL;
>>> + goto done;
>>> }
>>> error = qemu_file_get_error(f);
>>> if (error) {
>> } else if (flags & RAM_SAVE_FLAG_HOOK) {
>> ram_control_load_hook(f, flags);
>> + } else if (flags & RAM_SAVE_FLAG_EOS) {
>> + break;
>> + } else {
>> + ret = -EINVAL;
>> + goto done;
>> }
>> error = qemu_file_get_error(f);
>> if (error) {
we can also drop the error variable I think and change the loop to
while (!ret) {}
>> }
>>
>>
>> This way, we are checking RAM_SAVE_FLAG_EOS the same way than any other
>> flag? And we don't have to duplicate the FLAG_NAME?
> Ok, I will send a v2.
>
>> Unrelated to this patch, all the flags are a bitmap, but really, the
>> ones that can be together are RAM_SAVE_FLAG_CONTINUE and the rest, all
>> the others need to be alone. I am telling this because we have used
>> already 8 flags, and we are using the low bits of offset to save the
>> flags, we have 10 flags? Perhaps changing the last flag to mean that
>> the low bits pass to be a counter?
> Some better encoding would indeed be useful. I already thought
> that we might run out of flags soon. We have 11 flags I think,
> but there is not much space left. Reserving the last flag to indicate
> that the lower 10 bits a are counter might be a good option.
>
> Peter
>
>> PD. No, I haven't investigated right now how RAM_SAVE_FLAG_HOOK works
>> with all of this.
>>
>> Later, Juan.
>>
