1: per-domain IOMMU bitmap needs to have dynamic size
2: fix reduced page table levels support when sharing tables
3: don't needlessly engage the untrusted-MSI workaround

As to 4.16 considerations: Only patch 1 addresses a regression
introduced after 4.15, the others are older. Patch 3 additionally
only addresses an inefficiency; the code we have is correct from
a functional pov.

Jan

On 09.11.2021 15:55, Jan Beulich wrote:
> 1: per-domain IOMMU bitmap needs to have dynamic size
> 2: fix reduced page table levels support when sharing tables
> 3: don't needlessly engage the untrusted-MSI workaround
> 
> As to 4.16 considerations: Only patch 1 addresses a regression
> introduced after 4.15, the others are older.

To further explain this: Without the earlier change, systems with more
than 32 IOMMUs simply would fail to enable use of the IOMMUs altogether.
Now systems with more than 64 IOMMUs would observe memory corruption
(with unclear knock-on effects). Whether systems with this many IOMMUs
actually exist I can't tell; I know of ones with 40, which isn't all
that far away from 64.

Jan

> Patch 3 additionally
> only addresses an inefficiency; the code we have is correct from
> a functional pov.
> 
> Jan

> From: Jan Beulich <jbeulich@suse.com>
> Sent: Tuesday, November 9, 2021 10:56 PM
> 
> 1: per-domain IOMMU bitmap needs to have dynamic size
> 2: fix reduced page table levels support when sharing tables
> 3: don't needlessly engage the untrusted-MSI workaround
> 
> As to 4.16 considerations: Only patch 1 addresses a regression
> introduced after 4.15, the others are older. Patch 3 additionally
> only addresses an inefficiency; the code we have is correct from
> a functional pov.
> 

All look good to me:

	Reviewed-by: Kevin Tian <kevin.tian@intel.com>