Alexey Kardashevskiy <aik@xxxxxxx> writes:
> On 4/9/25 01:17, Aneesh Kumar K.V wrote:
>> Dan Williams <dan.j.williams@xxxxxxxxx> writes:
>> ...
>>
>>> +/**
>>> + * pci_tsm_bind() - Bind @pdev as a TDI for @kvm
>>> + * @pdev: PCI device function to bind
>>> + * @kvm: Private memory attach context
>>> + * @tdi_id: Identifier (virtual BDF) for the TDI as referenced by the TSM and DSM
>>> + *
>>> + * Returns 0 on success, or a negative error code on failure.
>>> + *
>>> + * Context: Caller is responsible for constraining the bind lifetime to the
>>> + * registered state of the device. For example, pci_tsm_bind() /
>>> + * pci_tsm_unbind() limited to the VFIO driver bound state of the device.
>>> + */
>>> +int pci_tsm_bind(struct pci_dev *pdev, struct kvm *kvm, u32 tdi_id)
>>> +{
>>> + const struct pci_tsm_ops *ops;
>>> + struct pci_tsm_pf0 *tsm_pf0;
>>> + struct pci_tdi *tdi;
>>> +
>>> + if (!kvm)
>>> + return -EINVAL;
>>> +
>>> + guard(rwsem_read)(&pci_tsm_rwsem);
>>> +
>>> + if (!pdev->tsm)
>>> + return -EINVAL;
>>> +
>>> + ops = pdev->tsm->ops;
>>> +
>>> + if (!is_link_tsm(ops->owner))
>>> + return -ENXIO;
>>> +
>>> + tsm_pf0 = to_pci_tsm_pf0(pdev->tsm);
>>> + guard(mutex)(&tsm_pf0->lock);
>>> +
>>> + /* Resolve races to bind a TDI */
>>> + if (pdev->tsm->tdi) {
>>> + if (pdev->tsm->tdi->kvm == kvm)
>>> + return 0;
>>> + else
>>> + return -EBUSY;
>>> + }
>>> +
>>> + tdi = ops->bind(pdev, kvm, tdi_id);
>>> + if (IS_ERR(tdi))
>>> + return PTR_ERR(tdi);
>>> +
>>> + pdev->tsm->tdi = tdi;
>>> +
>>> + return 0;
>>> +}
>>> +EXPORT_SYMBOL_GPL(pci_tsm_bind);
>>> +
>>
>> Are we missing assigning pdev and kvm in the above function?
>>
>> modified drivers/pci/tsm.c
>> @@ -356,6 +356,8 @@ int pci_tsm_bind(struct pci_dev *pdev, struct kvm *kvm, u32 tdi_id)
>> if (IS_ERR(tdi))
>> return PTR_ERR(tdi);
>>
>> + tdi->pdev = pdev;
>
> This signals that this pdev backref is not exactly needed :)
>
I need that in cca_tsm_unbind
static void cca_tsm_unbind(struct pci_tdi *tdi)
{
struct realm *realm = &tdi->kvm->arch.realm;
rme_unbind_vdev(realm, tdi->pdev, tdi->pdev->tsm->dsm);
module_put(THIS_MODULE);
}
-aneesh
