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

From: fangying
Date: Mon Mar 13 2017 - 10:59:49 EST

Hi, Huang Kai

After weeks of intensive testing, we think the problem is solved and this issue can be closed.

On 2017/2/27 15:38, Huang, Kai wrote:

On 2/25/2017 2:44 PM, Herongguang (Stephen) wrote:

On 2017/2/24 23:14, Paolo Bonzini wrote:

On 24/02/2017 16:10, Chris Friesen wrote:
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.


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

As its severity, this commit

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?

It should be the original issue.



Yes, I agree, though we are still testing.

Hi Stephen,

Sorry for late reply. I was taking the whole week off last week. How's
the test going?