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 5/6] PCI/TSM: Add pci_tsm_guest_req() for managing TDIs
Date: Wed, 5 Nov 2025 16:13:43 -0800 [thread overview]
Message-ID: <690be837cb8f0_74f761005@dwillia2-mobl4.notmuch> (raw)
In-Reply-To: <20251105153802.00004ddc@huawei.com>
Jonathan Cameron wrote:
> On Tue, 4 Nov 2025 20:00:54 -0800
> Dan Williams <dan.j.williams@intel.com> wrote:
>
> > A PCIe device function interface assigned to a TVM is a TEE Device
> > Interface (TDI). A TDI instantiated by pci_tsm_bind() needs additional
> > steps taken by the TVM to be accepted into the TVM's Trusted Compute
> > Boundary (TCB) and transitioned to the RUN state.
> >
> > pci_tsm_guest_req() is a channel for the guest to request TDISP collateral,
> > like Device Interface Reports, and effect TDISP state changes, like
> > LOCKED->RUN transititions. Similar to IDE establishment and pci_tsm_bind(),
> > these are long running operations involving SPDM message passing via the
> > DOE mailbox.
> >
> > The path for a TVM to invoke pci_tsm_guest_req() is:
> > * TSM triggers exit via guest-to-host-interface ABI (implementation specific)
> > * VMM invokes handler (KVM handle_exit() -> userspace io)
> > * handler issues request (userspace io handler -> ioctl() ->
> > pci_tsm_guest_req())
> > * handler supplies response
> > * VMM posts response, notifies/re-enters TVM
> >
> > This path is purely a transport for messages from TVM to platform TSM. By
> > design the host kernel does not and must not care about the content of
> > these messages. I.e. the host kernel is not in the TCB of the TVM.
> >
> > As this is an opaque passthrough interface, similar to fwctl, the kernel
> > requires that implementations stay within the bounds defined by 'enum
> > pci_tsm_req_scope'. Violation of those expectations likely has market and
> > regulatory consequences. Out of scope requests are blocked by default.
> >
> > 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>
> More triviality inline.
>
>
> > diff --git a/drivers/pci/tsm.c b/drivers/pci/tsm.c
> > index f0e38d7fee38..4dd518b45eea 100644
> > --- a/drivers/pci/tsm.c
> > +++ b/drivers/pci/tsm.c
> > @@ -354,6 +354,69 @@ int pci_tsm_bind(struct pci_dev *pdev, struct kvm *kvm, u32 tdi_id)
> > }
> > EXPORT_SYMBOL_GPL(pci_tsm_bind);
>
> > +ssize_t pci_tsm_guest_req(struct pci_dev *pdev, enum pci_tsm_req_scope scope,
> > + sockptr_t req_in, size_t in_len, sockptr_t req_out,
> > + size_t out_len, u64 *tsm_code)
> > +{
> > + struct pci_tsm_pf0 *tsm_pf0;
> > + struct pci_tdi *tdi;
> > + int rc;
> > +
> > + /*
> > + * Forbid requests that are not directly related to TDISP
> > + * operations
> > + */
>
> /* Forbid requests that are not directly related to TDISP operations */
> Is just under 80 chars.
Indeed it is. Probably a case of rewording but then not reflowing with
clang-format.
next prev parent reply other threads:[~2025-11-06 0:13 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
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 [this message]
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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