From: Jonathan Cameron <jonathan.cameron@huawei.com>
To: 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 15:38:02 +0000 [thread overview]
Message-ID: <20251105153802.00004ddc@huawei.com> (raw)
In-Reply-To: <20251105040055.2832866-6-dan.j.williams@intel.com>
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.
> + */
next prev parent reply other threads:[~2025-11-05 15:38 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 [this message]
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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