Re: [Qemu-devel] kvm bug in __rmap_clear_dirty during live migration

[Chris Friesen]

On 02/23/2017 08:23 PM, Herongguang (Stephen) wrote:

> On 2017/2/22 22:43, Paolo Bonzini wrote:

> > Hopefully Gaohuai and Rongguang can help with this too.
> >
> > Paolo
> >
> > .
> Yes, we are looking into and testing this.
>
> I think this can result in any memory corruption, if VM1 writes its
> PML buffer into VM2âs VMCS (since sched_in/sched_out notifier of VM1
> is not registered yet), then VM1 is destroyed (hence its PML buffer
> is freed back to kernel), after that, VM2 starts migration, so CPU
> logs VM2âs dirty GFNS into a freed memory, results in any memory corruption.
>
> As its severity, this commit
> (http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=4e59516a12a6ef6dcb660cb3a3f70c64bd60cfec)
>
> is eligible to back port to kernel stable.

Are we expecting that fix to resolve the original issue, or is it a separate 
issue that needs fixing in stable?

Chris