From: Jason Gunthorpe <jgg@nvidia.com>
To: Robin Murphy <robin.murphy@arm.com>
Cc: linaro-mm-sig@lists.linaro.org,
"Leon Romanovsky" <leon@kernel.org>,
kvm@vger.kernel.org, linux-rdma@vger.kernel.org,
"Daniel Vetter" <daniel.vetter@ffwll.ch>,
"Oded Gabbay" <ogabbay@kernel.org>,
"Cornelia Huck" <cohuck@redhat.com>,
dri-devel@lists.freedesktop.org,
"Christian König" <christian.koenig@amd.com>,
"Christoph Hellwig" <hch@infradead.org>,
"Alex Williamson" <alex.williamson@redhat.com>,
"Dan Williams" <dan.j.williams@intel.com>,
"Maor Gottlieb" <maorg@nvidia.com>,
"Sumit Semwal" <sumit.semwal@linaro.org>,
linux-media@vger.kernel.org
Subject: Re: [PATCH v2 4/4] vfio/pci: Allow MMIO regions to be exported through dma-buf
Date: Wed, 7 Sep 2022 13:47:24 -0300 [thread overview]
Message-ID: <YxjLHAw6rAcS/ax6@nvidia.com> (raw)
In-Reply-To: <6a42a8bc-4e2e-4502-3e7b-1a616dfee351@arm.com>
On Wed, Sep 07, 2022 at 05:31:14PM +0100, Robin Murphy wrote:
> The only trouble is that it's not geared for *PCI* P2P when that may or may
> not happen entirely upstream of IOMMU translation.
This is why PCI users have to call the pci_distance stuff before using
dma_map_resource(), it ensures the PCI fabric is setup in a way that
is consistent with the iommu. eg if we have IOMMU turned on then the
fabric must have ACS/etc to ensure that all TLPs are translated.
PCI P2P is very complicated and fragile, sadly.
Thanks,
Jason
next prev parent reply other threads:[~2022-09-07 16:47 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-31 23:12 [PATCH v2 0/4] Allow MMIO regions to be exported through dma-buf Jason Gunthorpe
2022-08-31 23:12 ` [PATCH v2 1/4] dma-buf: Add dma_buf_try_get() Jason Gunthorpe
2022-09-01 7:55 ` Christian König
2022-09-06 16:44 ` Jason Gunthorpe
2022-09-06 17:52 ` Christian König
2022-08-31 23:12 ` [PATCH v2 2/4] vfio: Add vfio_device_get() Jason Gunthorpe
2022-08-31 23:12 ` [PATCH v2 3/4] vfio_pci: Do not open code pci_try_reset_function() Jason Gunthorpe
2022-08-31 23:12 ` [PATCH v2 4/4] vfio/pci: Allow MMIO regions to be exported through dma-buf Jason Gunthorpe
[not found] ` <YxcYGzPv022G2vLm@infradead.org>
2022-09-06 10:38 ` Christian König
2022-09-06 11:48 ` Jason Gunthorpe
2022-09-06 12:34 ` Oded Gabbay
2022-09-06 17:59 ` Jason Gunthorpe
2022-09-06 19:44 ` Oded Gabbay
[not found] ` <YxiJJYtWgh1l0wxg@infradead.org>
2022-09-07 12:33 ` Jason Gunthorpe
[not found] ` <Yxiq5sjf/qA7xS8A@infradead.org>
2022-09-07 14:46 ` Oded Gabbay
2022-09-07 15:23 ` Jason Gunthorpe
[not found] ` <Yxi5h09JAzIo4Kh8@infradead.org>
2022-09-07 16:12 ` Jason Gunthorpe
[not found] ` <Yxs+k6psNfBLDqdv@infradead.org>
2022-09-09 14:09 ` Jason Gunthorpe
2022-09-07 16:31 ` Robin Murphy
2022-09-07 16:47 ` Jason Gunthorpe [this message]
2022-09-07 17:03 ` Dan Williams
2022-09-07 15:01 ` Robin Murphy
[not found] ` <YxiIkh/yeWQkZ54x@infradead.org>
2022-09-07 15:08 ` Christian König
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