Virtio-blk extended lifetime feature

[Enrico Granata]

Hi,
I am going to add +Jahdiel Alvarez who is also looking into a similar
issue, and also I would like to hear thoughts of people who may have
worked with (embedded or otherwise) storage more recently than I have

One thought that Jahdiel and myself were pondering is whether we need
"type_a" and "type_b" fields at all, or if there should simply be a
"wear estimate" field, which for eMMC, it could be max(typ_a, typ_b)
but it could generalize to any number of cell or other algorithm, as
long as it produces one unique estimate of wear

Thanks,
- Enrico

Thanks,
- Enrico


On Sun, Jan 15, 2023 at 12:56 AM Alvaro Karsz
<alvaro.karsz at solid-run.com> wrote:
>
> Hi guys,
>
> While trying to upstream the implementation of VIRTIO_BLK_F_LIFETIME
> feature, many developers suggested that this feature should be
> extended to include more cell types, since its current implementation
> in virtio spec is relevant for MMC and UFS devices only.
>
> The VIRTIO_BLK_F_LIFETIME defines the following fields:
>
> - pre_eol_info:  the percentage of reserved blocks that are consumed.
> - device_lifetime_est_typ_a: wear of SLC cells.
> - device_lifetime_est_typ_b: wear of MLC cells.
>
> (https://docs.oasis-open.org/virtio/virtio/v1.2/virtio-v1.2.html)
>
> Following Michael's suggestion, I'd like to add to the virtio spec
> with a new, extended lifetime command.
> Since I'm more familiar with embedded type storage devices, I'd like
> to ask you guys what fields you think should be included in the
> extended command.
>
> Thanks,
>
> Alvaro