Hi David,
As the DPDK 23.03 release is out can we have a relook at this change?
Thanks,
Nipun
> -----Original Message-----
> From: Gupta, Nipun
> Sent: Tuesday, February 7, 2023 2:27 PM
> To: David Marchand <[email protected]>;
> [email protected]
> Cc: [email protected]; [email protected]; Yigit, Ferruh
> <[email protected]>; Agarwal, Nikhil <[email protected]>
> Subject: RE: [PATCH v2] vfio: do not coalesce DMA mappings
>
> [AMD Official Use Only - General]
>
> Hi David,
>
> I agree that change is not straightforward to review, but it should not cause
> any
> functional issue as we are still creating all the memory mappings, but one by
> one
> for each segment.
> For hot plug case this causes issue as mentioned, that VFIO does not allow
> unmap of the individual segments in case mapping was created of a single
> coalesced segment.
>
> But yes, I am not sure why this code was added, which Anatoly may have more
> understanding on.
>
> Anatoly,
>
> Can you please provide your feedback on this change?
>
> Thanks,
> Nipun
>
> > -----Original Message-----
> > From: David Marchand <[email protected]>
> > Sent: Thursday, February 2, 2023 4:19 PM
> > To: [email protected]; Gupta, Nipun <[email protected]>
> > Cc: [email protected]; [email protected]; Yigit, Ferruh
> > <[email protected]>; Agarwal, Nikhil <[email protected]>
> > Subject: Re: [PATCH v2] vfio: do not coalesce DMA mappings
> >
> > Caution: This message originated from an External Source. Use proper caution
> > when opening attachments, clicking links, or responding.
> >
> >
> > Hi,
> >
> > On Wed, Jan 4, 2023 at 6:19 AM Nipun Gupta <[email protected]>
> wrote:
> > >
> > > At the cleanup time when dma unmap is done, linux kernel
> > > does not allow unmap of individual segments which were
> > > coalesced together while creating the DMA map for type1 IOMMU
> > > mappings. So, this change updates the mapping of the memory
> > > segments(hugepages) on a per-page basis.
> > >
> > > Signed-off-by: Nipun Gupta <[email protected]>
> > > Signed-off-by: Nikhil Agarwal <[email protected]>
> >
> > This change is scary.
> >
> > I won't take it without a review from the maintainer.
> > Anatoly, can you have a look?
> >
> >
> > Thanks.
> > --
> > David Marchand
