From: Christoph Hellwig <hch@infradead.org>
To: Keith Busch <kbusch@kernel.org>
Cc: Alex Williamson <alex.williamson@redhat.com>,
Jason Gunthorpe <jgg@ziepe.ca>, Keith Busch <kbusch@meta.com>,
kvm@vger.kernel.org
Subject: Re: [PATCH rfc] vfio-pci: Allow write combining
Date: Wed, 14 Aug 2024 22:05:06 -0700 [thread overview]
Message-ID: <Zr2Mgst5KNCvUlhV@infradead.org> (raw)
In-Reply-To: <ZqzsMcrEg5MCV48t@kbusch-mbp.dhcp.thefacebook.com>
On Fri, Aug 02, 2024 at 08:24:49AM -0600, Keith Busch wrote:
> Which itself follows the existing pattern from
> pci_create_resource_files(), which creates a write combine
> resource<X>_wc file only when IORESOURCE_PREFETCH is set. But yeah,
> prefetch isn't necessary for wc, but it seems to indicate it's safe.
Apparently IORESOURCE_PREFETCH never implied anything about write
combinability, and Linux got this wrong long time ago. The fact that
we do this now clashes with PCI SIGs desire to kill the concept of
prefetcable BARs that they are forcing down everyones throat.
prev parent reply other threads:[~2024-08-15 5:05 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-31 15:53 [PATCH rfc] vfio-pci: Allow write combining Keith Busch
2024-08-01 14:19 ` Jason Gunthorpe
2024-08-01 15:41 ` Alex Williamson
2024-08-01 16:11 ` Jason Gunthorpe
2024-08-01 16:52 ` Alex Williamson
2024-08-01 17:13 ` Jason Gunthorpe
2024-08-01 17:33 ` Alex Williamson
2024-08-01 17:53 ` Jason Gunthorpe
2024-08-01 18:16 ` Alex Williamson
2024-08-02 11:53 ` Jason Gunthorpe
2024-08-02 17:05 ` Alex Williamson
2024-08-06 16:53 ` Jason Gunthorpe
2024-08-06 18:43 ` Alex Williamson
2024-08-07 14:19 ` Jason Gunthorpe
2024-08-07 17:46 ` Alex Williamson
2024-08-13 18:02 ` Jason Gunthorpe
2024-08-02 14:24 ` Keith Busch
2024-08-02 14:33 ` Jason Gunthorpe
2024-08-06 7:19 ` Tian, Kevin
2024-08-06 16:47 ` Jason Gunthorpe
2024-08-15 5:05 ` Christoph Hellwig [this message]
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