Re: [PATCH v5 5/9] iommufd: Add an ioctl to query PA from IOVA for noiommu mode

[Jacob Pan]

Hi Yi,

On Wed, 20 May 2026 15:20:15 +0800
Yi Liu <yi.l.liu@xxxxxxxxx> wrote:

> From: Yi Liu <yi.l.liu@xxxxxxxxx>
> To: Jacob Pan <jacob.pan@xxxxxxxxxxxxxxxxxxx>,
> <linux-kernel@xxxxxxxxxxxxxxx>,  "iommu@xxxxxxxxxxxxxxx"
> <iommu@xxxxxxxxxxxxxxx>, Jason Gunthorpe  <jgg@xxxxxxxxxx>, Alex
> Williamson <alex@xxxxxxxxxxx>, Joerg Roedel  <joro@xxxxxxxxxx>,
> Mostafa Saleh <smostafa@xxxxxxxxxx>, David Matlack
> <dmatlack@xxxxxxxxxx>, Robin Murphy <robin.murphy@xxxxxxx>, Nicolin
> Chen  <nicolinc@xxxxxxxxxx>, "Tian, Kevin" <kevin.tian@xxxxxxxxx> CC:
> Saurabh Sengar <ssengar@xxxxxxxxxxxxxxxxxxx>, <skhawaja@xxxxxxxxxx>,
> <pasha.tatashin@xxxxxxxxxx>, Will Deacon <will@xxxxxxxxxx>, Baolu Lu
> <baolu.lu@xxxxxxxxxxxxxxx> Subject: Re: [PATCH v5 5/9] iommufd: Add
> an ioctl to query PA from IOVA for  noiommu mode Date: Wed, 20 May
> 2026 15:20:15 +0800 User-Agent: Mozilla Thunderbird
> 
> On 5/12/26 02:41, Jacob Pan wrote:
> > To support no-IOMMU mode where userspace drivers perform unsafe DMA
> > using physical addresses, introduce a new API to retrieve the
> > physical address of a user-allocated DMA buffer that has been
> > mapped to an IOVA via IOAS. The mapping is backed by SW-only I/O
> > page tables maintained by the generic IOMMUPT framework.
> > 
> > Suggested-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> > Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>  
> 
> since this patch is under your ahtuorship, maybe Jason's s-o-b should
> be prefixed with a c-d-b tag.
Missed this before, yeah, will do
 Suggested-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
 Co-developed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
 Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
 Signed-off-by: Jacob Pan <jacob.pan@xxxxxxxxxxxxxxxxxxx>