Re: [RFC PATCH 06/15] virt: tdx-guest: Support TDI bind and unbind operations

[Xiaoyao Li]

On 9/24/2026 12:10 PM, Zhenzhong Duan wrote:
> Introduce support for binding and unbinding the Trust Device Interface
> (TDI) using the TDCM_OP_BIND and TDCM_OP_UNBIND commands.
> 
> Executing TDCM_OP_BIND transitions the TDI state to a locked state
> (TDI_STATE_CONFIG_LOCKED). Add a sanity check following the bind operation
> to verify this state transition succeeded before finalizing device locking.

Can we expand it to talk more about the BIND and UNBIND?

> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@xxxxxxxxx>
> ---
>  drivers/virt/coco/tdx-guest/connect.c | 75 +++++++++++++++++++++++++++
>  1 file changed, 75 insertions(+)
> 
> diff --git a/drivers/virt/coco/tdx-guest/connect.c b/drivers/virt/coco/tdx-guest/connect.c
> index 1f52a187b30f..e36515fc43ef 100644
> --- a/drivers/virt/coco/tdx-guest/connect.c
> +++ b/drivers/virt/coco/tdx-guest/connect.c
> @@ -159,8 +159,67 @@ static bool tdx_is_dev_teeio_support(struct tdx_devsec *tdevsec)
>  	return !!rsp->is_supported;
>  }
>  
> +static struct tdx_devsec *tdx_tdi_bind_dev(struct tdx_devsec *tdevsec)
> +{
> +	struct pci_dev *pdev = tdevsec->pci.base_tsm.pdev;
> +	int ret;
> +
> +	struct tdcm_ctx *tdcm __free(tdx_tdcm_free) = tdx_tdcm_alloc(pdev, TDCM_OP_BIND, 0, 0);
> +	if (IS_ERR(tdcm))
> +		return ERR_CAST(tdcm);
> +
> +	ret = tdx_tdcm_run(tdcm);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	return tdevsec;
> +}

This return tdevsec and ...

> +
>  static struct pci_tsm *tdx_devsec_lock(struct tsm_dev *tsm_dev, struct pci_dev *pdev)
>  {
> +	u8 state;
>  	int ret;
>  
>  	struct tdx_devsec *tdevsec __free(kfree) = kzalloc(sizeof(*tdevsec), GFP_KERNEL);
> @@ -174,6 +233,19 @@ static struct pci_tsm *tdx_devsec_lock(struct tsm_dev *tsm_dev, struct pci_dev *
>  	if (!tdx_is_dev_teeio_support(tdevsec))
>  		return ERR_PTR(-EOPNOTSUPP);
>  
> +	struct tdx_devsec *tdevsec_bind __free(tdx_tdi_unbind_dev) = tdx_tdi_bind_dev(tdevsec);

... the __free(tdx_tdi_unbind_dev) are not easy to follow.

I'm worried if it is OK to Dave given the previous discussion[1]

[1] https://lore.kernel.org/all/70056924-1702-4020-b805-014efb87afdd@xxxxxxxxx/

> +	if (IS_ERR(tdevsec_bind))
> +		return ERR_CAST(tdevsec_bind);
> +
> +	ret = tdx_tdi_read_state(tdevsec, &state);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	if (state != TDI_STATE_CONFIG_LOCKED)
> +		return ERR_PTR(-EIO);
> +
> +	retain_and_null_ptr(tdevsec_bind);
> +
>  	return &no_free_ptr(tdevsec)->pci.base_tsm;
>  }
>  
> @@ -181,6 +253,9 @@ static void tdx_devsec_unlock(struct pci_tsm *tsm)
>  {
>  	struct tdx_devsec *tdevsec = to_tdx_devsec(tsm);
>  
> +	if (WARN_ON(tdx_tdi_unbind_dev(tdevsec)))
> +		return;
> +
>  	kfree(tdevsec);
>  }
>