[libvirt] [PATCH v2] qemu: snapshot: Forbid internal snapshots with pflash firmware

[Laszlo Ersek]

On 03/24/17 14:23, Peter Krempa wrote:
> On Fri, Mar 24, 2017 at 14:04:08 +0100, Laszlo Ersek wrote:
>> On 03/24/17 13:46, Peter Krempa wrote:
>>> On Thu, Mar 23, 2017 at 17:49:56 +0100, Laszlo Ersek wrote:
>>>> On 03/23/17 15:07, Peter Krempa wrote:
> 
> [...]
> 
>>>
>>> I'll post a v3 with the option to override it, if users insist that they
>>> don't care about the state of their varstore.
>>
>> Thank you, this all sounds good to me.
> 
> I've already posted v3, but forgot to CC you:
> 
> https://www.redhat.com/archives/libvir-list/2017-March/msg01151.html
> 
> 
>>
>> Could you please test v3 with both live (online) and offline OVMF VMs,
>> with and without --unsafe? (That is, four cases in total.)
> 
> Sigh. I've thought that I tested this properly, but libvirt code is not
> able to detect the failure from taking the snapshot and thus thinks it
> created the snapshot properly.
> 
> I've got:
> 
> {"return": "Device 'pflash1' is writable but does not support snapshots.\r\n", "id": "libvirt-37"}
> 
> This is due to the fact that 'savevm' uses HMP passthrough and the code
> to detect errors sucks.
> 
> Sorry for the noise.
> 
> v3 is not necessary with all the fancy code. I'll push v2 with a better
> explanation, since it fixes an actual bug :/

Thanks! It's just as well that we've been thorough enough to track this
down, so that's a plus at least.

Laszlo