From: <dan.j.williams@intel.com>
To: Jonathan Cameron <jonathan.cameron@huawei.com>,
Dan Williams <dan.j.williams@intel.com>
Cc: <linux-pci@vger.kernel.org>, <linux-coco@lists.linux.dev>,
<bhelgaas@google.com>, <aneesh.kumar@kernel.org>,
<yilun.xu@linux.intel.com>, <aik@amd.com>
Subject: Re: [PATCH 4/6] PCI/TSM: Add pci_tsm_bind() helper for instantiating TDIs
Date: Wed, 5 Nov 2025 16:11:59 -0800 [thread overview]
Message-ID: <690be7cfa9803_74f7610037@dwillia2-mobl4.notmuch> (raw)
In-Reply-To: <20251105153126.00002a0a@huawei.com>
Jonathan Cameron wrote:
> On Tue, 4 Nov 2025 20:00:53 -0800
> Dan Williams <dan.j.williams@intel.com> wrote:
>
> > After a PCIe device has established a secure link and session between a TEE
> > Security Manager (TSM) and its local Device Security Manager (DSM), the
> > device or its subfunctions are candidates to be bound to a private memory
> > context, a TVM. A PCIe device function interface assigned to a TVM is a TEE
> > Device Interface (TDI).
> >
> > The pci_tsm_bind() requests the low-level TSM driver to associate the
> > device with private MMIO and private IOMMU context resources of a given TVM
> > represented by a @kvm argument. A device in the bound state corresponds to
> > the TDISP protocol LOCKED state and awaits validation by the TVM. It is a
> > 'struct pci_tsm_link_ops' operation because, similar to IDE establishment,
> > it involves host side resource establishment and context setup on behalf of
> > the guest. It is also expected to be performed lazily to allow for
> > operation of the device in non-confidential "shared" context for pre-lock
> > configuration.
> >
> > Co-developed-by: Xu Yilun <yilun.xu@linux.intel.com>
> > Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>
> > Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> Trivial comments only from me.
>
> > diff --git a/drivers/pci/tsm.c b/drivers/pci/tsm.c
> > index 6a2849f77adc..f0e38d7fee38 100644
> > --- a/drivers/pci/tsm.c
> > +++ b/drivers/pci/tsm.c
>
>
[..]
> > + /* Resolve races to bind a TDI */
> > + if (pdev->tsm->tdi) {
> > + if (pdev->tsm->tdi->kvm == kvm)
> > + return 0;
> I'd flip so the error case is out of line. Then drop the else.
>
>
> if (pdev->tsm->tdi->kvm != kvm)
> return -EBUSY;
>
> return 0;
Looks good.
diff --git a/drivers/pci/tsm.c b/drivers/pci/tsm.c
index 7df2a681ed19..001afdf00de6 100644
--- a/drivers/pci/tsm.c
+++ b/drivers/pci/tsm.c
@@ -381,10 +381,9 @@ int pci_tsm_bind(struct pci_dev *pdev, struct kvm *kvm, u32 tdi_id)
/* Resolve races to bind a TDI */
if (pdev->tsm->tdi) {
- if (pdev->tsm->tdi->kvm == kvm)
- return 0;
- else
+ if (pdev->tsm->tdi->kvm != kvm)
return -EBUSY;
+ return 0;
}
tdi = to_pci_tsm_ops(pdev->tsm)->bind(pdev, kvm, tdi_id);
next prev parent reply other threads:[~2025-11-06 0:12 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-05 4:00 [PATCH 0/6] PCI/TSM: Finalize "Link" TSM infrastructure Dan Williams
2025-11-05 4:00 ` [PATCH 1/6] resource: Introduce resource_assigned() for discerning active resources Dan Williams
2025-11-05 9:17 ` Jonathan Cameron
2025-11-05 21:57 ` dan.j.williams
2025-11-05 4:00 ` [PATCH 2/6] PCI/IDE: Add Address Association Register setup for downstream MMIO Dan Williams
2025-11-05 9:58 ` Jonathan Cameron
2025-11-05 23:04 ` dan.j.williams
2025-11-10 11:49 ` Jonathan Cameron
2025-11-05 4:00 ` [PATCH 3/6] PCI/IDE: Initialize an ID for all IDE streams Dan Williams
2025-11-05 15:27 ` Jonathan Cameron
2025-11-05 23:51 ` dan.j.williams
2025-11-10 11:52 ` Jonathan Cameron
2025-11-05 4:00 ` [PATCH 4/6] PCI/TSM: Add pci_tsm_bind() helper for instantiating TDIs Dan Williams
2025-11-05 4:59 ` Aneesh Kumar K.V
2025-11-05 21:49 ` dan.j.williams
2025-11-05 15:31 ` Jonathan Cameron
2025-11-06 0:11 ` dan.j.williams [this message]
2025-11-05 4:00 ` [PATCH 5/6] PCI/TSM: Add pci_tsm_guest_req() for managing TDIs Dan Williams
2025-11-05 15:38 ` Jonathan Cameron
2025-11-06 0:13 ` dan.j.williams
2025-11-05 4:00 ` [PATCH 6/6] PCI/TSM: Add 'dsm' and 'bound' attributes for dependent functions Dan Williams
2025-11-05 17:53 ` Jonathan Cameron
2025-11-13 12:10 ` Jonathan Cameron
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