Re: [PATCH] iommu/amd-vi: adjust _amd_iommu_flush_pages() to handle pseudo-domids

[Jan Beulich <jbeulich@suse.com>]

On 14.06.2023 10:32, Roger Pau Monne wrote:
> When the passed domain is DomIO iterate over the list of DomIO
> assigned devices and flush each pseudo-domid found.
> 
> invalidate_all_domain_pages() does call amd_iommu_flush_all_pages()
> with DomIO as a parameter,

Does it? Since the full function is visible in the patch (because of
the "While there ..." change), it seems pretty clear that it doesn't:
for_each_domain() iterates over ordinary domains only.

> and hence the underlying
> _amd_iommu_flush_pages() implementation must be capable of flushing
> all pseudo-domids used by the quarantine domain logic.

While it didn't occur to me right away when we discussed this, it
may well be that I left alone all flushing when introducing the pseudo
domain IDs simply because no flushing would ever happen for the
quarantine domain.

> While there fix invalidate_all_domain_pages() to only attempt to flush
> the domains that have IOMMU enabled, otherwise the flush is pointless.

For the moment at least it looks to me as if this change alone wants
to go in.

Jan