Re: [Qemu-devel] [PATCH 0/3 v2] virtio: improve virtio devices initialization time

["Kinsella, Ray" <mdr@ashroe.eu>]

Hi Gal,

Brilliant - will test this in the next day or two.
Hopefully this will help resolve the issues I reported last summer.

http://lists.nongnu.org/archive/html/qemu-devel/2017-07/msg05268.html

Ray K

On 14/01/2018 10:06, Gal Hammer wrote:
> A bug was reported about a very slow boot time and a 100% CPU usage of
> both Windows and Linux guests when running a VM with multiple
> virtio-serial devices (https://bugzilla.redhat.com/1528588).
>
> For example, running a VM with 25 virtio-serial devices, each one with
> max_ports=511, could have a boot time of around 30 minutes. With this
> patch (and another patch to kvm) the boot time is reduced to
> approximately 3 minutes.
>
> The patch wraps all the changes made to the Memory Regions during the
> eventfd registrations in a memory regions transaction. I had to add a
> cleanup callback function to the EventNotifier struct, so it will be
> possible to use a transaction in the shutdown code path as well.
>
> Gal Hammer (3):
>    qemu: add a cleanup callback function to EventNotifier
>    virtio: postpone the execution of event_notifier_cleanup function
>    virtio: improve virtio devices initialization time
>
>   accel/kvm/kvm-all.c           |  4 ++++
>   hw/virtio/virtio-bus.c        | 19 +++++++++++--------
>   hw/virtio/virtio.c            |  5 +++++
>   include/qemu/event_notifier.h |  1 +
>   util/event_notifier-posix.c   |  5 ++++-
>   util/event_notifier-win32.c   |  2 ++
>   6 files changed, 27 insertions(+), 9 deletions(-)
>