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Diffstat (limited to 'Documentation/security/tpm/xen-tpmfront.txt')
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diff --git a/Documentation/security/tpm/xen-tpmfront.txt b/Documentation/security/tpm/xen-tpmfront.txt deleted file mode 100644 index 69346de87ff3..000000000000 --- a/Documentation/security/tpm/xen-tpmfront.txt +++ /dev/null @@ -1,113 +0,0 @@ -Virtual TPM interface for Xen - -Authors: Matthew Fioravante (JHUAPL), Daniel De Graaf (NSA) - -This document describes the virtual Trusted Platform Module (vTPM) subsystem for -Xen. The reader is assumed to have familiarity with building and installing Xen, -Linux, and a basic understanding of the TPM and vTPM concepts. - -INTRODUCTION - -The goal of this work is to provide a TPM functionality to a virtual guest -operating system (in Xen terms, a DomU). This allows programs to interact with -a TPM in a virtual system the same way they interact with a TPM on the physical -system. Each guest gets its own unique, emulated, software TPM. However, each -of the vTPM's secrets (Keys, NVRAM, etc) are managed by a vTPM Manager domain, -which seals the secrets to the Physical TPM. If the process of creating each of -these domains (manager, vTPM, and guest) is trusted, the vTPM subsystem extends -the chain of trust rooted in the hardware TPM to virtual machines in Xen. Each -major component of vTPM is implemented as a separate domain, providing secure -separation guaranteed by the hypervisor. The vTPM domains are implemented in -mini-os to reduce memory and processor overhead. - -This mini-os vTPM subsystem was built on top of the previous vTPM work done by -IBM and Intel corporation. - - -DESIGN OVERVIEW ---------------- - -The architecture of vTPM is described below: - -+------------------+ -| Linux DomU | ... -| | ^ | -| v | | -| xen-tpmfront | -+------------------+ - | ^ - v | -+------------------+ -| mini-os/tpmback | -| | ^ | -| v | | -| vtpm-stubdom | ... -| | ^ | -| v | | -| mini-os/tpmfront | -+------------------+ - | ^ - v | -+------------------+ -| mini-os/tpmback | -| | ^ | -| v | | -| vtpmmgr-stubdom | -| | ^ | -| v | | -| mini-os/tpm_tis | -+------------------+ - | ^ - v | -+------------------+ -| Hardware TPM | -+------------------+ - - * Linux DomU: The Linux based guest that wants to use a vTPM. There may be - more than one of these. - - * xen-tpmfront.ko: Linux kernel virtual TPM frontend driver. This driver - provides vTPM access to a Linux-based DomU. - - * mini-os/tpmback: Mini-os TPM backend driver. The Linux frontend driver - connects to this backend driver to facilitate communications - between the Linux DomU and its vTPM. This driver is also - used by vtpmmgr-stubdom to communicate with vtpm-stubdom. - - * vtpm-stubdom: A mini-os stub domain that implements a vTPM. There is a - one to one mapping between running vtpm-stubdom instances and - logical vtpms on the system. The vTPM Platform Configuration - Registers (PCRs) are normally all initialized to zero. - - * mini-os/tpmfront: Mini-os TPM frontend driver. The vTPM mini-os domain - vtpm-stubdom uses this driver to communicate with - vtpmmgr-stubdom. This driver is also used in mini-os - domains such as pv-grub that talk to the vTPM domain. - - * vtpmmgr-stubdom: A mini-os domain that implements the vTPM manager. There is - only one vTPM manager and it should be running during the - entire lifetime of the machine. This domain regulates - access to the physical TPM on the system and secures the - persistent state of each vTPM. - - * mini-os/tpm_tis: Mini-os TPM version 1.2 TPM Interface Specification (TIS) - driver. This driver used by vtpmmgr-stubdom to talk directly to - the hardware TPM. Communication is facilitated by mapping - hardware memory pages into vtpmmgr-stubdom. - - * Hardware TPM: The physical TPM that is soldered onto the motherboard. - - -INTEGRATION WITH XEN --------------------- - -Support for the vTPM driver was added in Xen using the libxl toolstack in Xen -4.3. See the Xen documentation (docs/misc/vtpm.txt) for details on setting up -the vTPM and vTPM Manager stub domains. Once the stub domains are running, a -vTPM device is set up in the same manner as a disk or network device in the -domain's configuration file. - -In order to use features such as IMA that require a TPM to be loaded prior to -the initrd, the xen-tpmfront driver must be compiled in to the kernel. If not -using such features, the driver can be compiled as a module and will be loaded -as usual. |