Re: [PATCH v4 00/15] vfio: VFIO migration support with vIOMMU

[Cédric Le Goater]

Hello Joao,

> Cedric, you mentioned that you take a look at this after you come back, not sure
> if that's still the plan. But it's been a while since the last version, so would
> you have me repost/rebase on the latest (post your PR)?

Yes please. That's next on the TODO list (after some downstream work
regarding the postcopy crash). My rough plan for 8.2 is :

 * P2P
 * VIOMMU
 * dynamic MSI-X
 * fixes

I think it is a bit early for iommufd and I will probably lack time.
The recent migration addition is requiring some attention in many
areas.

> Additionally, I should say that I have an alternative (as a single small patch),
> where vIOMMU usage is allowed ... but behind a VFIO command line option, and as
> soon as attempt *any* vIOMMU mapping we fail-to-start/block the migration. I
> haven't posted that alternative as early in the dirty tracking work the idea was
> to avoid guest vIOMMU usage dependency to allow migration (which made this
> patchset the way it is). But thought it was OK to remind, if it was only be
> allowed if the admin explicitly states such its intent behind a x- command line
> option.

I don't remember seeing it. It is worth resending as an RFC so that
people can comment.

Thanks,

C.