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From: Alex Mastro <amastro@fb.com>
To: Alex Williamson <alex@shazbot.org>
Cc: David Matlack <dmatlack@google.com>,
	Shuah Khan <shuah@kernel.org>, Jason Gunthorpe <jgg@ziepe.ca>,
	<kvm@vger.kernel.org>, <linux-kselftest@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 4/4] vfio: selftests: replace iova=vaddr with allocated iovas
Date: Tue, 11 Nov 2025 09:21:43 -0800	[thread overview]
Message-ID: <aRNwp5v1kOdr+Of9@devgpu015.cco6.facebook.com> (raw)
In-Reply-To: <20251111100937.4706a54e.alex@shazbot.org>

On Tue, Nov 11, 2025 at 10:09:37AM -0700, Alex Williamson wrote:
> On Tue, 11 Nov 2025 06:52:05 -0800
> Alex Mastro <amastro@fb.com> wrote:
> 
> > vfio_dma_mapping_test and vfio_pci_driver_test currently use iova=vaddr
> > as part of DMA mapping operations. The assumption that these IOVAs
> > are legal has held up on all the hardware we've tested so far, but is
> > not guaranteed. Make the tests more robust by using iova_allocator to
> > vend IOVAs, which queries legally accessible IOVAs from the underlying
> > IOMMUFD or VFIO container.
> 
> I've reported hardware that it doesn't work on, QEMU emulates such
> hardware.  The commit message suggests this is more of a theoretical
> problem.  Thanks,

Agree that it's misleading. I'll update the commit message to describe the
things you described earlier.

  reply	other threads:[~2025-11-11 17:21 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-11-11 14:52 [PATCH v2 0/4] vfio: selftests: update DMA mapping tests to use queried IOVA ranges Alex Mastro
2025-11-11 14:52 ` [PATCH v2 1/4] vfio: selftests: add iova range query helpers Alex Mastro
2025-11-11 17:09   ` Alex Williamson
2025-11-11 17:35     ` Alex Mastro
2025-11-11 17:52       ` Alex Williamson
2025-11-11 17:59         ` Alex Mastro
2025-11-11 14:52 ` [PATCH v2 2/4] vfio: selftests: fix map limit tests to use last available iova Alex Mastro
2025-11-11 14:52 ` [PATCH v2 3/4] vfio: selftests: add iova allocator Alex Mastro
2025-11-11 14:52 ` [PATCH v2 4/4] vfio: selftests: replace iova=vaddr with allocated iovas Alex Mastro
2025-11-11 17:09   ` Alex Williamson
2025-11-11 17:21     ` Alex Mastro [this message]
2025-11-11 17:10 ` [PATCH v2 0/4] vfio: selftests: update DMA mapping tests to use queried IOVA ranges Alex Williamson
2025-11-11 17:41 ` David Matlack
2025-11-11 18:49   ` Alex Mastro

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