From: Fred Griffoul <griffoul@gmail.com>
To: "Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org>,
linux-coco@lists.linux.dev
Cc: Ackerley Tng <ackerleytng@google.com>,
Alex Williamson <alex@shazbot.org>,
David Woodhouse <dwmw2@infradead.org>,
David Hildenbrand <david@kernel.org>,
Jason Gunthorpe <jgg@ziepe.ca>,
"Joerg Roedel (AMD)" <joro@8bytes.org>,
Kevin Tian <kevin.tian@intel.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Robin Murphy <robin.murphy@arm.com>,
Sean Christopherson <seanjc@google.com>,
Will Deacon <will@kernel.org>, Alexey Kardashevskiy <aik@amd.com>,
Xu Yilun <yilun.xu@linux.intel.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Steven Price <steven.price@arm.com>,
iommu@lists.linux.dev, kvm@vger.kernel.org,
patches@lists.linux.dev
Subject: Re: [RFC PATCH v3 07/13] KVM: guest_memfd: Support private/shared conversion of device memory
Date: Tue, 3 Nov 2026 19:38:50 +0000 [thread overview]
Message-ID: <20261103193850.15363-1-griffoul@gmail.com> (raw)
In-Reply-To: <20261101071928.2462549-8-aneesh.kumar@kernel.org>
"Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org> writes:
> + if (!slot)
> + return -EINVAL;
[...]
> + ret = kvm_arch_gmem_device_map(gi->device.kvm, slot, gpa,
> + (u64)(high - first) << PAGE_SHIFT,
> + PFN_PHYS(pfn));
> + if (ret)
> + return ret;
Unless I'm missing something, these returns leave the pieces already
mapped in place, while the attributes stay shared. A later conversion
to shared would then find nothing to do, and a retry of this
conversion would run into the pieces that are mapped.
Would it make sense for the error path to unmap what was mapped, e.g.
with kvm_gmem_invalidate_start() and KVM_FILTER_PRIVATE on the range?
Fred
next prev parent reply other threads:[~2026-11-03 19:38 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-01 7:19 [RFC PATCH v3 00/13] KVM: guest_memfd: Add a common framework for device memory providers Aneesh Kumar K.V (Arm)
2026-11-01 7:19 ` [RFC PATCH v3 01/13] KVM: guest_memfd: Let providers prepare memory regions Aneesh Kumar K.V (Arm)
2026-11-01 7:19 ` [RFC PATCH v3 02/13] KVM: guest_memfd: Dispatch attribute conversion through backing operations Aneesh Kumar K.V (Arm)
2026-11-01 7:19 ` [RFC PATCH v3 03/13] KVM: guest_memfd: Let providers coordinate mapping changes Aneesh Kumar K.V (Arm)
2026-11-01 7:19 ` [RFC PATCH v3 04/13] KVM: guest_memfd: Dispatch revocation through backing operations Aneesh Kumar K.V (Arm)
2026-11-01 7:19 ` [RFC PATCH v3 05/13] KVM: guest_memfd: Split population by backing type Aneesh Kumar K.V (Arm)
2026-11-01 7:19 ` [RFC PATCH v3 06/13] KVM: guest_memfd: Support device-backed PFN providers Aneesh Kumar K.V (Arm)
2026-11-03 23:12 ` Ackerley Tng
2026-11-01 7:19 ` [RFC PATCH v3 07/13] KVM: guest_memfd: Support private/shared conversion of device memory Aneesh Kumar K.V (Arm)
2026-11-03 19:38 ` Fred Griffoul [this message]
2026-11-01 7:19 ` [RFC PATCH v3 08/13] KVM: guest_memfd: Track private device ranges after attribute updates Aneesh Kumar K.V (Arm)
2026-11-01 7:19 ` [RFC PATCH v3 09/13] KVM: guest_memfd: Expose device provider private state Aneesh Kumar K.V (Arm)
2026-11-01 7:19 ` [RFC PATCH v3 10/13] KVM: guest_memfd: Support range revocation of device mappings Aneesh Kumar K.V (Arm)
2026-11-01 7:19 ` [RFC PATCH v3 11/13] KVM: guest_memfd: Add shared device mmap through PFN providers Aneesh Kumar K.V (Arm)
2026-11-01 7:19 ` [RFC PATCH v3 12/13] KVM: guest_memfd: Remove device mappings on final close Aneesh Kumar K.V (Arm)
2026-11-01 7:19 ` [RFC PATCH v3 13/13] KVM: guest_memfd: Invalidate guest_memfd mappings before removing memslot bindings Aneesh Kumar K.V (Arm)
2026-11-02 13:40 ` [RFC PATCH v3 00/13] KVM: guest_memfd: Add a common framework for device memory providers Aneesh Kumar K.V
2026-11-03 18:36 ` Fred Griffoul
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20261103193850.15363-1-griffoul@gmail.com \
--to=griffoul@gmail.com \
--cc=ackerleytng@google.com \
--cc=aik@amd.com \
--cc=alex@shazbot.org \
--cc=aneesh.kumar@kernel.org \
--cc=catalin.marinas@arm.com \
--cc=david@kernel.org \
--cc=dwmw2@infradead.org \
--cc=iommu@lists.linux.dev \
--cc=jgg@ziepe.ca \
--cc=joro@8bytes.org \
--cc=kevin.tian@intel.com \
--cc=kvm@vger.kernel.org \
--cc=linux-coco@lists.linux.dev \
--cc=patches@lists.linux.dev \
--cc=pbonzini@redhat.com \
--cc=robin.murphy@arm.com \
--cc=seanjc@google.com \
--cc=steven.price@arm.com \
--cc=suzuki.poulose@arm.com \
--cc=will@kernel.org \
--cc=yilun.xu@linux.intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox