linux-kernel - Re: [PATCH v2 03/10] PCI/P2PDMA: Refactor to separate core P2P functionality from memory allocation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250925163131.22a2c09b.alex.williamson@redhat.com>
Date: Thu, 25 Sep 2025 16:31:31 -0600
From: Alex Williamson <alex.williamson@...hat.com>
To: Jason Gunthorpe <jgg@...dia.com>
Cc: Leon Romanovsky <leon@...nel.org>, Andrew Morton
 <akpm@...ux-foundation.org>, Bjorn Helgaas <bhelgaas@...gle.com>, Christian
 König <christian.koenig@....com>,
 dri-devel@...ts.freedesktop.org, iommu@...ts.linux.dev, Jens Axboe
 <axboe@...nel.dk>, Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
 linaro-mm-sig@...ts.linaro.org, linux-block@...r.kernel.org,
 linux-kernel@...r.kernel.org, linux-media@...r.kernel.org,
 linux-mm@...ck.org, linux-pci@...r.kernel.org, Logan Gunthorpe
 <logang@...tatee.com>, Marek Szyprowski <m.szyprowski@...sung.com>, Robin
 Murphy <robin.murphy@....com>, Sumit Semwal <sumit.semwal@...aro.org>,
 Vivek Kasireddy <vivek.kasireddy@...el.com>, Will Deacon <will@...nel.org>
Subject: Re: [PATCH v2 03/10] PCI/P2PDMA: Refactor to separate core P2P
 functionality from memory allocation

On Thu, 25 Sep 2025 08:53:08 -0300
Jason Gunthorpe <jgg@...dia.com> wrote:

> On Thu, Sep 25, 2025 at 10:03:14AM +0300, Leon Romanovsky wrote:
> 
> > > It would at least make sense to me then to store the provider on the
> > > vfio_pci_dma_buf object at the time of the get feature call rather than
> > > vfio_pci_core_init_dev() though.  That would eliminate patch 08/ and
> > > the inline #ifdefs.  
> > 
> > I'll change it now. If "enable" function goes to be "get" function, we
> > won't need to store anything in vfio_pci_dma_buf too. At the end, we
> > have exactly two lines "provider = priv->vdev->provider[priv->bar];",
> > which can easily be changed to be "provider = pcim_p2pdma_provider(priv->vdev->pdev, priv->bar)"  
> 
> Not without some kind of locking change. I'd keep the
> priv->vdev->provider[priv->bar] because setup during probe doesn't
> need special locking.

Why do we need to store the provider on the vfio_pci_core_device at
probe though, we can get it later via pcim_p2pdma_provider().  Ideally
we'd take the opportunity to pull out the setup part of the _provider
function to give us an initialization interface to use at probe time
without an unnecessary BAR# arg.  Thanks,

Alex