On 17.07.19 12:48, Michael S. Tsirkin wrote:
> On Wed, Jul 17, 2019 at 12:35:50PM +0200, David Hildenbrand wrote:
>> When a guest reboots (ordinary reboots, but also via kexec), it will
>> happily reuse any system memory, including previously inflated memory.
>>
>> We could have tracking data for a pbp (PartiallyBalloonedPage). It could
>> happen that a new inflation request from the guest will result in a
>> discard of such a pbp, although the guest is (again) reusing some
>> memory.
>>
>> We should reset the pbp on any device resets.
>>
>> Fixes: ed48c59875b6 ("virtio-balloon: Safely handle BALLOON_PAGE_SIZE <
>> host page size")
>> Cc: qemu-sta...@nongnu.org #v4.0.0
>> Cc: Stefan Hajnoczi <stefa...@redhat.com>
>> Cc: David Gibson <da...@gibson.dropbear.id.au>
>> Cc: Michael S. Tsirkin <m...@redhat.com>
>> Cc: Igor Mammedov <imamm...@redhat.com>
>> Signed-off-by: David Hildenbrand <da...@redhat.com>
>
> Can't something else remove a ramblock besides a reset?
Yes, however this patch is not about ramblocks getting removed.
Take a close look, "balloon->pbp->rb" is only used as a token, it is
never used besides for comparisons.
--
Thanks,
David / dhildenb
