On 3/11/25 04:42, Stefano Garzarella wrote:
> SNP platform can provide a vTPM device emulated by SVSM.
>
> The "tpm-svsm" device can be handled by the platform driver added
> by the previous commit in drivers/char/tpm/tpm_svsm.c
>
> The driver will call snp_svsm_vtpm_probe() to check if SVSM is
> present and if it's support the vTPM protocol.
>
> Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
> ---
> arch/x86/coco/sev/core.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c
> index 2166bdff88b7..a2383457889e 100644
> --- a/arch/x86/coco/sev/core.c
> +++ b/arch/x86/coco/sev/core.c
> @@ -2664,6 +2664,11 @@ static struct platform_device sev_guest_device = {
> .id = -1,
> };
>
> +static struct platform_device tpm_svsm_device = {
> + .name = "tpm-svsm",
> + .id = -1,
> +};
> +
> static int __init snp_init_platform_device(void)
> {
> if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
> @@ -2672,6 +2677,9 @@ static int __init snp_init_platform_device(void)
> if (platform_device_register(&sev_guest_device))
> return -ENODEV;
>
> + if (platform_device_register(&tpm_svsm_device))
> + return -ENODEV;
> +
You could avoid registering the device if an SVSM isn't present. Not sure
if that is desirable or not.
Thanks,
Tom
> pr_info("SNP guest platform device initialized.\n");
> return 0;
> }
