From: Christoph Hellwig <hch@lst.de>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Roman Kisel <romank@linux.microsoft.com>,
Robin Murphy <robin.murphy@arm.com>,
aleksander.lobakin@intel.com, andriy.shevchenko@linux.intel.com,
arnd@arndb.de, bp@alien8.de, catalin.marinas@arm.com,
corbet@lwn.net, dakr@kernel.org, dave.hansen@linux.intel.com,
decui@microsoft.com, gregkh@linuxfoundation.org,
haiyangz@microsoft.com, hch@lst.de, hpa@zytor.com,
James.Bottomley@hansenpartnership.com,
Jonathan.Cameron@huawei.com, kys@microsoft.com, leon@kernel.org,
lukas@wunner.de, luto@kernel.org, m.szyprowski@samsung.com,
martin.petersen@oracle.com, mingo@redhat.com,
peterz@infradead.org, quic_zijuhu@quicinc.com,
tglx@linutronix.de, wei.liu@kernel.org, will@kernel.org,
iommu@lists.linux.dev, linux-arch@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org,
linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-scsi@vger.kernel.org, x86@kernel.org, apais@microsoft.com,
benhill@microsoft.com, bperkins@microsoft.com,
sunilmut@microsoft.com, Suzuki K Poulose <suzuki.poulose@arm.com>,
linux-coco@lists.linux.dev
Subject: Re: [PATCH hyperv-next 5/6] arch, drivers: Add device struct bitfield to not bounce-buffer
Date: Thu, 10 Apr 2025 09:23:54 +0200 [thread overview]
Message-ID: <20250410072354.GB32563@lst.de> (raw)
In-Reply-To: <67f703099f124_71fe2949e@dwillia2-xfh.jf.intel.com.notmuch>
On Wed, Apr 09, 2025 at 04:30:17PM -0700, Dan Williams wrote:
> > Thanks, I should've highlighted that facet most certainly!
>
> One would hope that no one is building a modern device with trusted I/O
> capability, *and* with a swiotlb addressing dependency. However, I agree
> that a non-shared swiotlb would be needed in such a scenario.
Hope is never a good idea when dealing with hardware :( PCIe already
requires no addressing limitations, and programming interface specs
like NVMe double down on that. But at least one big hyperscaler still
managed to build such a device.
Also even if the periphal device is not addressing limited, the root
port or interconnect might still be, we've seen quite a lot of that.
next prev parent reply other threads:[~2025-04-10 7:24 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20250409000835.285105-1-romank@linux.microsoft.com>
[not found] ` <20250409000835.285105-6-romank@linux.microsoft.com>
[not found] ` <0eb87302-fae8-4708-aaf8-d16e836e727f@arm.com>
[not found] ` <0ab2849a-5c03-4a8c-891e-3cb89b20b0e4@linux.microsoft.com>
2025-04-09 23:30 ` [PATCH hyperv-next 5/6] arch, drivers: Add device struct bitfield to not bounce-buffer Dan Williams
2025-04-10 1:16 ` Michael Kelley
2025-04-11 0:03 ` Dan Williams
2025-04-10 7:23 ` Christoph Hellwig [this message]
2025-04-10 23:44 ` Jason Gunthorpe
2025-04-10 23:50 ` Jason Gunthorpe
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