lkml.org 
[lkml]   [2021]   [Sep]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 12/12] swiotlb-xen: this is PV-only on x86
On Tue, Sep 07, 2021 at 02:13:21PM +0200, Jan Beulich wrote:
> The code is unreachable for HVM or PVH, and it also makes little sense
> in auto-translated environments. On Arm, with
> xen_{create,destroy}_contiguous_region() both being stubs, I have a hard
> time seeing what good the Xen specific variant does - the generic one
> ought to be fine for all purposes there. Still Arm code explicitly
> references symbols here, so the code will continue to be included there.

Can the Xen/arm folks look into that? Getting ARM out of using
swiotlb-xen would be a huge step forward cleaning up some DMA APIs.

>
> Instead of making PCI_XEN's "select" conditional, simply drop it -
> SWIOTLB_XEN will be available unconditionally in the PV case anyway, and
> is - as explained above - dead code in non-PV environments.
>
> This in turn allows dropping the stubs for
> xen_{create,destroy}_contiguous_region(), the former of which was broken
> anyway - it failed to set the DMA handle output.

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

\
 
 \ /
  Last update: 2021-09-08 09:17    [W:0.208 / U:0.780 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site