Re: [virtio] [PATCH 4/5] packed-ring: reposition drivernormative on driver notifications

[Paolo Bonzini <pbonzini@redhat.com>]

On 09/04/2018 20:58, Halil Pasic wrote:
>  The driver has to be careful to expose the new \field{flags}
>  value before checking if notifications are suppressed.

This paragraph should also be reworked to be part of the normative text
below, I think?  The memory barrier must be "between two things", and
only with this paragraph you know that it's between the flags write and
the suppression structure read.

Thanks,

Paolo

> +\drivernormative{\paragraph}{Notifying The Device}{Basic Facilities of a Virtio Device / Packed Virtqueues / Supplying Buffers to The Device / Notifying The Device}
> +The driver MUST perform a suitable memory barrier before reading
> +the Driver Event Suppression structure, to avoid missing a notification.
> +