Re: propagating vmgenid outward and upward

[Jason A. Donenfeld]

Hi Michael,

On Wed, Mar 02, 2022 at 11:22:46AM -0500, Michael S. Tsirkin wrote:
> > Because that 16 byte read of vmgenid is not atomic. Let's say you read
> > the first 8 bytes, and then the VM is forked.
> 
> But at this point when VM was forked plaintext key and nonce are all in
> buffer, and you previously indicated a fork at this point is harmless.
> You wrote "If it changes _after_ that point of check ... it doesn't
> matter:"

Ahhh, fair point. I think you're right.

Alright, so all we're talking about here is an ordinary 16-byte read,
and 16 bytes of storage per keypair, and a 16-byte comparison.

Still seems much worse than just having a single word...

Jason