From: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: sashiko-reviews@lists.linux.dev, iommu@lists.linux.dev,
linux-coco@lists.linux.dev
Subject: Re: [PATCH v7 16/16] PCI/TSM: wait for vdevice contexts before removing a DSM
Date: Tue, 13 Oct 2026 15:14:54 +0530 [thread overview]
Message-ID: <yq5aecduq6i1.fsf@kernel.org> (raw)
In-Reply-To: <20261012130739.GM13920@nvidia.com>
Jason Gunthorpe <jgg@nvidia.com> writes:
> On Mon, Oct 12, 2026 at 03:31:17PM +0530, Aneesh Kumar K.V wrote:
>
>> With this series, vdevices hold a reference to their parent vIOMMU,
>> which pins arm-cca-host. sysfs unbind is disabled, and the SMCCC
>> provider device has no hot-unplug path.
>
> It probably needs some logic like vfio has to prevent unregister from
> completing if there are active users. The module pin should prevent it
> from ever triggering, but as a safety precaution.
>
Are you suggesting that tsm_unregister() should return an error or wait,
as device removal does? Returning an error would be much easier to
implement by adding an unregistering flag to tsm_dev, set under
pci_tsm_rwsem after checking all pf0->context_users counters.
-aneesh
next prev parent reply other threads:[~2026-10-13 9:44 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-08 5:59 [PATCH v7 00/16] iommufd: vIOMMUs and TSM guest requests for confidential guests Aneesh Kumar K.V (Arm)
2026-10-08 5:59 ` [PATCH v7 01/16] KVM: Introduce file_to_kvm_<arch>() infrastructure Aneesh Kumar K.V (Arm)
2026-10-08 5:59 ` [PATCH v7 02/16] KVM: Add file back-pointer to struct kvm Aneesh Kumar K.V (Arm)
2026-10-08 5:59 ` [PATCH v7 03/16] KVM: x86: Use file_to_kvm_x86() in SEV Aneesh Kumar K.V (Arm)
2026-10-08 5:59 ` [PATCH v7 04/16] KVM/vfio: Use file-based reference counting for KVM Aneesh Kumar K.V (Arm)
2026-10-08 5:59 ` [PATCH v7 05/16] KVM: Restrict kvm_get_kvm/kvm_put_kvm export to internal KVM modules Aneesh Kumar K.V (Arm)
2026-10-08 5:59 ` [PATCH v7 06/16] KVM: Remove unused file_is_kvm Aneesh Kumar K.V (Arm)
2026-10-08 5:59 ` [PATCH v7 07/16] iommufd/device: Associate KVM file pointer with iommufd_device Aneesh Kumar K.V (Arm)
2026-10-08 5:59 ` [PATCH v7 08/16] iommufd/viommu: Keep a reference to the KVM file Aneesh Kumar K.V (Arm)
2026-10-08 5:59 ` [PATCH v7 09/16] tsm: Remove the device from lookup before PCI teardown Aneesh Kumar K.V (Arm)
[not found] ` <sashiko-outbox-163673@kernel.org>
2026-10-12 9:14 ` Aneesh Kumar K.V
2026-10-12 13:01 ` Jason Gunthorpe
2026-10-13 8:49 ` Aneesh Kumar K.V
2026-10-13 11:57 ` Jason Gunthorpe
2026-10-08 5:59 ` [PATCH v7 10/16] iommufd: Add the vdevice TSM request ioctl Aneesh Kumar K.V (Arm)
2026-10-08 5:59 ` [PATCH v7 11/16] PCI/TSM: Remove the legacy guest request interface Aneesh Kumar K.V (Arm)
2026-10-08 5:59 ` [PATCH v7 12/16] PCI/TSM: Add vIOMMU-bound contexts for vdevices Aneesh Kumar K.V (Arm)
2026-10-08 5:59 ` [PATCH v7 13/16] iommufd/viommu: Select vIOMMU operations before allocation Aneesh Kumar K.V (Arm)
2026-10-08 5:59 ` [PATCH v7 14/16] iommufd/viommu: Allow PCI TSM backends to provide vIOMMU operations Aneesh Kumar K.V (Arm)
[not found] ` <sashiko-outbox-163680@kernel.org>
2026-10-12 9:55 ` Aneesh Kumar K.V
2026-10-08 5:59 ` [PATCH v7 15/16] iommufd: Allow vIOMMUs without a parent HWPT Aneesh Kumar K.V (Arm)
2026-10-08 5:59 ` [PATCH v7 16/16] PCI/TSM: wait for vdevice contexts before removing a DSM Aneesh Kumar K.V (Arm)
[not found] ` <sashiko-outbox-163687@kernel.org>
2026-10-12 10:01 ` Aneesh Kumar K.V
2026-10-12 13:07 ` Jason Gunthorpe
2026-10-13 9:44 ` Aneesh Kumar K.V [this message]
2026-10-13 11:59 ` Jason Gunthorpe
2026-10-12 20:34 ` Bjorn Helgaas
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