devtpm0

devtpm0 refers to a Linux device node associated with the Device TPM (devtpm) subsystem, a kernel interface designed to provide access to Trusted Platform Module (TPM) hardware or emulated TPMs from user space. The devtpm framework aims to offer a stable, uniform path for TPM communication across different backends and deployment scenarios, including bare-metal hardware, virtualized environments, and containerized workloads.

On systems with devtpm support enabled, the TPM device may appear as /dev/devtpm0. Some configurations may still expose a legacy TPM node such as /dev/tpm0 or /dev/tpmrm0, but devtpm provides an alternative interface that can be used by TPM software stacks (for example, TPM2 software tools and libraries) and virtualization tooling that require a consistent TPM access mechanism. The presence and naming of the device depend on kernel version, distribution policies, and whether the hardware TPM or a software-emulated TPM is bound to the devtpm driver.

Typical use of devtpm involves applications and services that perform TPM operations, such as cryptographic background services, attestation, or remote provisioning workflows. In virtualized setups, devtpm can also facilitate delivering a TPM to guests or containers in a manner that helps isolate TPM usage from host processes.

Security considerations include standard Linux permissions controlling access to the device file and the need to ensure that TPM operations are performed by authorized software. As with other TPM interfaces, devtpm adheres to the TPM 2.0 specification for command formatting and responses.

See also: Trusted Platform Module, tpm_tis, tpm_crb, /dev/tpm0, tpm2-tools, abrmd, virtualization.