Re: [RFC PATCH 05/15] virt: tdx-guest: Add TDCM helpers and TEE-IO support check

[Nikolay Borisov <nik.borisov@suse.com>]

On 24.09.26 г. 7:10 ч., Zhenzhong Duan wrote:
> Implement internal helper wrappers tdx_tdcm_alloc(), tdx_tdcm_run(),
> and tdx_tdcm_free() to manage execution context lifecycle for TDX Connect
> TEE-IO Device Control and Management (TDCM) commands.
> 
> Use these infrastructures to deploy all TDCM commands to orchestrate
> trusted device management, beginning with the first command,
> TDCM_OP_CHECK_TEEIO_SUPP, executed during the secure device locking
> sequence.
> 
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
> ---
>   arch/x86/include/asm/tdx.h            |  48 +++++++++
>   drivers/virt/coco/tdx-guest/connect.c | 139 ++++++++++++++++++++++++++
>   2 files changed, 187 insertions(+)
> 
> diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
> index 4937e23d5483..71cd701d346f 100644
> --- a/arch/x86/include/asm/tdx.h
> +++ b/arch/x86/include/asm/tdx.h
> @@ -105,6 +105,54 @@ int tdx_mcall_extend_rtmr(u8 index, u8 *data);
>   u64 tdx_hcall_get_quote(u8 *buf, size_t size);
>   
>   #ifdef CONFIG_TDX_CONNECT_GUEST
> +enum tdcm_operation {
> +	TDCM_OP_CHECK_TEEIO_SUPP	= 1,
> +	TDCM_OP_BIND			= 2,
> +	TDCM_OP_GET_DEV_INFO		= 3,
> +	TDCM_OP_GET_TDI_REPORT		= 4,
> +	TDCM_OP_START_TDI		= 5,
> +	TDCM_OP_GET_TDI_STATE		= 6,
> +	TDCM_OP_UNBIND			= 7,
> +};
> +
> +enum tdcm_status {
> +	TDCM_STATUS_WAIT		= 0,
> +	TDCM_STATUS_COMPLETED		= 1,
> +	TDCM_STATUS_ERROR		= 2,
> +};
> +
> +enum tdcm_error {
> +	TDCM_ERROR_TDX_MODULE		= 10,
> +	TDCM_ERROR_TDXIO_DEVICE		= 11,
> +	TDCM_ERROR_SPDM_MESSAGE		= 12,
> +	TDCM_ERROR_IDE_KM_MESSAGE	= 13,
> +	TDCM_ERROR_TDISP_MESSAGE	= 14,
> +	TDCM_ERROR_INVALID_STATE	= 15,
> +};
> +
> +struct tdvmcall_tdcm {
> +	__u16 operation;  /* See enum tdcm_operation */
> +	__u8  version;
> +	__u8  rsvd0;
> +	__u32 rsvd1;
> +
> +	__u8  status;     /* See enum tdcm_status */
> +	__u8  error;      /* See enum tdcm_error */
> +	__u16 rsvd2;
> +	__u32 rsvd3;
> +
> +	__u32 data_length;
> +
> +	__u8  data[];
> +} __packed;
> +
> +struct tdcm_rsp_check_teeio_supp {
> +	__u8 is_supported;
> +	__u8  data[];
> +} __packed;
> +
> +#define MAX_TDI_REPORT_SIZE	(16 * PAGE_SIZE)

Since TDCM and all concepts around it are coupled to TDX Connect why are 
those defines in the shared tdx.h file? OTOH, why is struct tdcm_ctx {} 
defined in connect.c and not in the shared file? I think it's high time 
we decided whether code coming for additional functionality should go 
into the shared header or a file, specific to said functionality.

My 2 cents are that since TDCM is solely related to connect then it 
should probably be part of connect.h or some private header under 
tdx-guest/ directory. It's not expected for kernel proper to use that 
interface, no ?

<snip>