From: Dan Williams <dan.j.williams@intel.com>
To: Logan Gunthorpe <logang@deltatee.com>
Cc: "Christoph Hellwig" <hch@lst.de>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
linux-nvme@lists.infradead.org, linux-block@vger.kernel.org,
"Linux PCI" <linux-pci@vger.kernel.org>,
"Linux MM" <linux-mm@kvack.org>,
"open list:DMA MAPPING HELPERS"
<iommu@lists.linux-foundation.org>,
"Stephen Bates" <sbates@raithlin.com>,
"Jason Gunthorpe" <jgg@ziepe.ca>,
"Christian König" <christian.koenig@amd.com>,
"Ira Weiny" <iweiny@intel.com>,
"John Hubbard" <jhubbard@nvidia.com>,
"Don Dutile" <ddutile@redhat.com>,
"Matthew Wilcox" <willy@infradead.org>,
"Daniel Vetter" <daniel.vetter@ffwll.ch>
Subject: Re: [RFC PATCH 04/15] lib/scatterlist: Add flag for indicating P2PDMA segments in an SGL
Date: Wed, 9 Dec 2020 17:22:09 -0800 [thread overview]
Message-ID: <CAPcyv4ifGcrdOtUt8qr7pmFhmecGHqGVre9G0RorGczCGVECQQ@mail.gmail.com> (raw)
In-Reply-To: <4e336c7e-207b-31fa-806e-c4e8028524a5@deltatee.com>
On Mon, Nov 9, 2020 at 8:47 AM Logan Gunthorpe <logang@deltatee.com> wrote:
>
>
>
> On 2020-11-09 2:12 a.m., Christoph Hellwig wrote:
> > On Fri, Nov 06, 2020 at 10:00:25AM -0700, Logan Gunthorpe wrote:
> >> We make use of the top bit of the dma_length to indicate a P2PDMA
> >> segment.
> >
> > I don't think "we" can. There is nothing limiting the size of a SGL
> > segment.
>
> Yes, I expected this would be the unacceptable part. Any alternative ideas?
Why is the SG_P2PDMA_FLAG needed as compared to checking the SGL
segment-pages for is_pci_p2pdma_page()?
WARNING: multiple messages have this Message-ID (diff)
From: Dan Williams <dan.j.williams@intel.com>
To: Logan Gunthorpe <logang@deltatee.com>
Cc: "Jason Gunthorpe" <jgg@ziepe.ca>,
"Linux PCI" <linux-pci@vger.kernel.org>,
"Daniel Vetter" <daniel.vetter@ffwll.ch>,
"Ira Weiny" <iweiny@intel.com>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
linux-nvme@lists.infradead.org,
"Stephen Bates" <sbates@raithlin.com>,
linux-block@vger.kernel.org, "Linux MM" <linux-mm@kvack.org>,
"open list:DMA MAPPING HELPERS"
<iommu@lists.linux-foundation.org>,
"Don Dutile" <ddutile@redhat.com>,
"Matthew Wilcox" <willy@infradead.org>,
"John Hubbard" <jhubbard@nvidia.com>,
"Christian König" <christian.koenig@amd.com>,
"Christoph Hellwig" <hch@lst.de>
Subject: Re: [RFC PATCH 04/15] lib/scatterlist: Add flag for indicating P2PDMA segments in an SGL
Date: Wed, 9 Dec 2020 17:22:09 -0800 [thread overview]
Message-ID: <CAPcyv4ifGcrdOtUt8qr7pmFhmecGHqGVre9G0RorGczCGVECQQ@mail.gmail.com> (raw)
In-Reply-To: <4e336c7e-207b-31fa-806e-c4e8028524a5@deltatee.com>
On Mon, Nov 9, 2020 at 8:47 AM Logan Gunthorpe <logang@deltatee.com> wrote:
>
>
>
> On 2020-11-09 2:12 a.m., Christoph Hellwig wrote:
> > On Fri, Nov 06, 2020 at 10:00:25AM -0700, Logan Gunthorpe wrote:
> >> We make use of the top bit of the dma_length to indicate a P2PDMA
> >> segment.
> >
> > I don't think "we" can. There is nothing limiting the size of a SGL
> > segment.
>
> Yes, I expected this would be the unacceptable part. Any alternative ideas?
Why is the SG_P2PDMA_FLAG needed as compared to checking the SGL
segment-pages for is_pci_p2pdma_page()?
_______________________________________________
Linux-nvme mailing list
Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme
WARNING: multiple messages have this Message-ID (diff)
From: Dan Williams <dan.j.williams@intel.com>
To: Logan Gunthorpe <logang@deltatee.com>
Cc: "Jason Gunthorpe" <jgg@ziepe.ca>,
"Linux PCI" <linux-pci@vger.kernel.org>,
"Daniel Vetter" <daniel.vetter@ffwll.ch>,
"Ira Weiny" <iweiny@intel.com>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
linux-nvme@lists.infradead.org,
"Stephen Bates" <sbates@raithlin.com>,
linux-block@vger.kernel.org, "Linux MM" <linux-mm@kvack.org>,
"open list:DMA MAPPING HELPERS"
<iommu@lists.linux-foundation.org>,
"Matthew Wilcox" <willy@infradead.org>,
"John Hubbard" <jhubbard@nvidia.com>,
"Christian König" <christian.koenig@amd.com>,
"Christoph Hellwig" <hch@lst.de>
Subject: Re: [RFC PATCH 04/15] lib/scatterlist: Add flag for indicating P2PDMA segments in an SGL
Date: Wed, 9 Dec 2020 17:22:09 -0800 [thread overview]
Message-ID: <CAPcyv4ifGcrdOtUt8qr7pmFhmecGHqGVre9G0RorGczCGVECQQ@mail.gmail.com> (raw)
In-Reply-To: <4e336c7e-207b-31fa-806e-c4e8028524a5@deltatee.com>
On Mon, Nov 9, 2020 at 8:47 AM Logan Gunthorpe <logang@deltatee.com> wrote:
>
>
>
> On 2020-11-09 2:12 a.m., Christoph Hellwig wrote:
> > On Fri, Nov 06, 2020 at 10:00:25AM -0700, Logan Gunthorpe wrote:
> >> We make use of the top bit of the dma_length to indicate a P2PDMA
> >> segment.
> >
> > I don't think "we" can. There is nothing limiting the size of a SGL
> > segment.
>
> Yes, I expected this would be the unacceptable part. Any alternative ideas?
Why is the SG_P2PDMA_FLAG needed as compared to checking the SGL
segment-pages for is_pci_p2pdma_page()?
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2020-12-10 1:23 UTC|newest]
Thread overview: 126+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-06 17:00 [RFC PATCH 00/15] Userspace P2PDMA with O_DIRECT NVMe devices Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` [RFC PATCH 01/15] PCI/P2PDMA: Don't sleep in upstream_bridge_distance_warn() Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-09 9:12 ` Christoph Hellwig
2020-11-09 9:12 ` Christoph Hellwig
2020-11-09 9:12 ` Christoph Hellwig
2020-11-06 17:00 ` [RFC PATCH 02/15] PCI/P2PDMA: Attempt to set map_type if it has not been set Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` [RFC PATCH 03/15] PCI/P2PDMA: Introduce pci_p2pdma_should_map_bus() and pci_p2pdma_bus_offset() Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-10 23:25 ` Bjorn Helgaas
2020-11-10 23:25 ` Bjorn Helgaas
2020-11-10 23:25 ` Bjorn Helgaas
2020-11-10 23:42 ` Logan Gunthorpe
2020-11-10 23:42 ` Logan Gunthorpe
2020-11-10 23:42 ` Logan Gunthorpe
2020-11-06 17:00 ` [RFC PATCH 04/15] lib/scatterlist: Add flag for indicating P2PDMA segments in an SGL Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-09 9:12 ` Christoph Hellwig
2020-11-09 9:12 ` Christoph Hellwig
2020-11-09 9:12 ` Christoph Hellwig
2020-11-09 14:02 ` Robin Murphy
2020-11-09 14:02 ` Robin Murphy
2020-11-09 14:02 ` Robin Murphy
2020-11-09 16:47 ` Logan Gunthorpe
2020-11-09 16:47 ` Logan Gunthorpe
2020-11-09 16:47 ` Logan Gunthorpe
2020-12-10 1:22 ` Dan Williams [this message]
2020-12-10 1:22 ` Dan Williams
2020-12-10 1:22 ` Dan Williams
2020-12-10 2:06 ` Logan Gunthorpe
2020-12-10 2:06 ` Logan Gunthorpe
2020-12-10 2:06 ` Logan Gunthorpe
2020-12-10 4:04 ` Dan Williams
2020-12-10 4:04 ` Dan Williams
2020-12-10 4:04 ` Dan Williams
2020-12-10 16:44 ` Logan Gunthorpe
2020-12-10 16:44 ` Logan Gunthorpe
2020-12-10 16:44 ` Logan Gunthorpe
2020-11-06 17:00 ` [RFC PATCH 05/15] dma-direct: Support PCI P2PDMA pages in dma-direct map_sg Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` [RFC PATCH 06/15] dma-mapping: Add flags to dma_map_ops to indicate PCI P2PDMA support Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` [RFC PATCH 07/15] iommu/dma: Support PCI P2PDMA pages in dma-iommu map_sg Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` [RFC PATCH 08/15] nvme-pci: Check DMA ops when indicating support for PCI P2PDMA Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` [RFC PATCH 09/15] nvme-pci: Convert to using dma_map_sg for p2pdma pages Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` [RFC PATCH 10/15] mm: Introduce FOLL_PCI_P2PDMA to gate getting PCI P2PDMA pages Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` [RFC PATCH 11/15] iov_iter: Introduce iov_iter_get_pages_[alloc_]flags() Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` [RFC PATCH 12/15] block: Set FOLL_PCI_P2PDMA in __bio_iov_iter_get_pages() Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` [RFC PATCH 13/15] block: Set FOLL_PCI_P2PDMA in bio_map_user_iov() Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` [RFC PATCH 14/15] PCI/P2PDMA: Introduce pci_mmap_p2pmem() Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:22 ` Jason Gunthorpe
2020-11-06 17:22 ` Jason Gunthorpe
2020-11-06 17:22 ` Jason Gunthorpe
2020-11-06 17:28 ` Logan Gunthorpe
2020-11-06 17:28 ` Logan Gunthorpe
2020-11-06 17:28 ` Logan Gunthorpe
2020-11-06 17:42 ` Jason Gunthorpe
2020-11-06 17:42 ` Jason Gunthorpe
2020-11-06 17:42 ` Jason Gunthorpe
2020-11-06 17:53 ` Logan Gunthorpe
2020-11-06 17:53 ` Logan Gunthorpe
2020-11-06 17:53 ` Logan Gunthorpe
2020-11-06 18:09 ` Jason Gunthorpe
2020-11-06 18:09 ` Jason Gunthorpe
2020-11-06 18:09 ` Jason Gunthorpe
2020-11-06 18:20 ` Logan Gunthorpe
2020-11-06 18:20 ` Logan Gunthorpe
2020-11-06 18:20 ` Logan Gunthorpe
2020-11-06 19:30 ` Jason Gunthorpe
2020-11-06 19:30 ` Jason Gunthorpe
2020-11-06 19:30 ` Jason Gunthorpe
2020-11-06 19:44 ` Logan Gunthorpe
2020-11-06 19:44 ` Logan Gunthorpe
2020-11-06 19:44 ` Logan Gunthorpe
2020-11-06 19:53 ` Jason Gunthorpe
2020-11-06 19:53 ` Jason Gunthorpe
2020-11-06 19:53 ` Jason Gunthorpe
2020-11-06 20:03 ` Logan Gunthorpe
2020-11-06 20:03 ` Logan Gunthorpe
2020-11-06 20:03 ` Logan Gunthorpe
2020-11-07 0:14 ` Jason Gunthorpe
2020-11-07 0:14 ` Jason Gunthorpe
2020-11-07 0:14 ` Jason Gunthorpe
2020-11-07 2:50 ` Logan Gunthorpe
2020-11-07 2:50 ` Logan Gunthorpe
2020-11-07 2:50 ` Logan Gunthorpe
2020-11-06 17:00 ` [RFC PATCH 15/15] nvme-pci: Allow mmaping the CMB in userspace Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:00 ` Logan Gunthorpe
2020-11-06 17:39 ` Jason Gunthorpe
2020-11-06 17:39 ` Jason Gunthorpe
2020-11-06 17:39 ` Jason Gunthorpe
2020-11-06 17:43 ` Logan Gunthorpe
2020-11-06 17:43 ` Logan Gunthorpe
2020-11-06 17:43 ` Logan Gunthorpe
2020-11-09 15:03 ` Keith Busch
2020-11-09 15:03 ` Keith Busch
2020-11-09 15:03 ` Keith Busch
2020-11-09 16:50 ` Logan Gunthorpe
2020-11-09 16:50 ` Logan Gunthorpe
2020-11-09 16:50 ` Logan Gunthorpe
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