Re: [PATCH 0/2] exclude hyperv synic sections from vhost

[Jason Wang <jasowang@redhat.com>]

On 2020/1/8 下午9:53, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> Hyperv's synic (that we emulate) is a feature that allows the guest
> to place some magic (4k) pages of RAM anywhere it likes in GPA.
> This confuses vhost's RAM section merging when these pages
> land over the top of hugepages.


Hi David:

A silly question, is this because the alignment when adding sections? If 
yes, what's the reason for doing alignment which is not a must for vhost 
memory table.

Thanks


>
> Since they're not normal RAM, and they shouldn't have vhost DMAing
> into them, exclude them from the vhost set.
>
> I do that by marking them as device-ram and then excluding device-ram
> from vhost.
>
> bz: https://bugzilla.redhat.com/show_bug.cgi?id=1779041
>
> Dr. David Alan Gilbert (2):
>    vhost: Don't pass ram device sections
>    hyperv/synic: Allocate as ram_device
>
>   hw/hyperv/hyperv.c | 14 ++++++++------
>   hw/virtio/vhost.c  |  1 +
>   2 files changed, 9 insertions(+), 6 deletions(-)
>