From: Jason Gunthorpe <jgg@nvidia.com>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Oliver Upton <oliver.upton@linux.dev>,
Ankit Agrawal <ankita@nvidia.com>,
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<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v3 1/1] KVM: arm64: Allow cacheable stage 2 mapping using VMA flags
Date: Wed, 23 Apr 2025 10:03:23 -0300 [thread overview]
Message-ID: <20250423130323.GE1648741@nvidia.com> (raw)
In-Reply-To: <aAjci3rddHt_R_x3@arm.com>
On Wed, Apr 23, 2025 at 01:26:51PM +0100, Catalin Marinas wrote:
> Ah, good point. So we want a strict cacheable mapping even if there is
> no user/VMM mapping alias. Is it because KVM cannot do cache maintenance
> on the PFNMAP or because the device does not support other memory types?
> Both valid reasons though.
Lack of cache maintenance is the main problem for the vfio-grace device
> In this case KVM still needs to know the properties of the device. Not
> sure how it could best do this without a vma.
Well, the idea I hope to succeed with would annotate this kind of
information inside the page list that would be exchanged through the
FD.
There is an monstrous thread here about this topic:
https://lore.kernel.org/all/20250107142719.179636-1-yilun.xu@linux.intel.com/
I can't find it in the huge thread but I did explain some thoughts on
how it could work
Jason
next prev parent reply other threads:[~2025-04-23 13:03 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-10 10:30 [PATCH v3 0/1] KVM: arm64: Map GPU device memory as cacheable ankita
2025-03-10 10:30 ` [PATCH v3 1/1] KVM: arm64: Allow cacheable stage 2 mapping using VMA flags ankita
2025-03-10 11:54 ` Marc Zyngier
2025-03-11 3:42 ` Ankit Agrawal
2025-03-11 11:18 ` Marc Zyngier
2025-03-11 12:07 ` Ankit Agrawal
2025-03-12 8:21 ` Marc Zyngier
2025-03-17 5:55 ` Ankit Agrawal
2025-03-17 9:27 ` Marc Zyngier
2025-03-17 19:54 ` Catalin Marinas
2025-03-18 9:39 ` Marc Zyngier
2025-03-18 12:55 ` Jason Gunthorpe
2025-03-18 19:27 ` Catalin Marinas
2025-03-18 19:35 ` David Hildenbrand
2025-03-18 19:40 ` Oliver Upton
2025-03-20 3:30 ` bibo mao
2025-03-20 7:24 ` bibo mao
2025-03-18 23:17 ` Jason Gunthorpe
2025-03-19 18:03 ` Catalin Marinas
2025-03-18 19:30 ` Oliver Upton
2025-03-18 23:09 ` Jason Gunthorpe
2025-03-19 7:01 ` Oliver Upton
2025-03-19 17:04 ` Jason Gunthorpe
2025-03-19 18:11 ` Catalin Marinas
2025-03-19 19:22 ` Jason Gunthorpe
2025-03-19 21:48 ` Catalin Marinas
2025-03-26 8:31 ` Ankit Agrawal
2025-03-26 14:53 ` Sean Christopherson
2025-03-26 15:42 ` Marc Zyngier
2025-03-26 16:10 ` Sean Christopherson
2025-03-26 18:02 ` Marc Zyngier
2025-03-26 18:24 ` Sean Christopherson
2025-03-26 18:51 ` Oliver Upton
2025-03-31 14:44 ` Jason Gunthorpe
2025-03-31 14:56 ` Jason Gunthorpe
2025-04-07 15:20 ` Sean Christopherson
2025-04-07 16:15 ` Jason Gunthorpe
2025-04-07 16:43 ` Sean Christopherson
2025-04-16 8:51 ` Ankit Agrawal
2025-04-21 16:03 ` Ankit Agrawal
2025-04-22 7:49 ` Oliver Upton
2025-04-22 13:54 ` Jason Gunthorpe
2025-04-22 16:50 ` Catalin Marinas
2025-04-22 17:03 ` Jason Gunthorpe
2025-04-22 21:28 ` Oliver Upton
2025-04-22 23:35 ` Jason Gunthorpe
2025-04-23 10:45 ` Catalin Marinas
2025-04-23 12:02 ` Jason Gunthorpe
2025-04-23 12:26 ` Catalin Marinas
2025-04-23 13:03 ` Jason Gunthorpe [this message]
2025-04-29 10:47 ` Ankit Agrawal
2025-04-29 13:27 ` Catalin Marinas
2025-04-29 14:14 ` Jason Gunthorpe
2025-04-29 16:03 ` Catalin Marinas
2025-04-29 16:44 ` Jason Gunthorpe
2025-04-29 18:09 ` Catalin Marinas
2025-04-29 18:19 ` Jason Gunthorpe
2025-05-07 15:26 ` Ankit Agrawal
2025-05-09 12:47 ` Catalin Marinas
2025-04-22 14:53 ` Sean Christopherson
2025-03-18 12:57 ` Jason Gunthorpe
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