This enables the use of swtpm (from meta-security) as a virtual TPM in
qemu. These patches extend the existing support in qemu for TPM
passthrough so that a swtpm daemon can be accessed via CUSE (character
device in user space).
To use this:
- add the meta-security layer including the swtpm enhancements for qemu
- bitbake swtpm-native
- create a TPM instance and initialize it with:
$ mkdir -p my-machine/myvtpm0
$ tmp-glibc/sysroots/x86_64-linux/usr/bin/swtpm_setup_oe.sh --tpm-state my-machine/myvtpm0 --createek
Starting vTPM manufacturing as root:root @ Fri 20 Jan 2017 08:56:18 AM CET
TPM is listening on TCP port 52167.
Successfully created EK.
Successfully authored TPM state.
Ending vTPM manufacturing @ Fri 20 Jan 2017 08:56:19 AM CET
- run swtpm *before each runqemu invocation* (it shuts down after use) and
do it as root (required to set up the /dev/vtpm0 CUSE device):
$ sudo sh -c 'PATH=`pwd`/tmp-glibc/sysroots/x86_64-linux/usr/bin/:`pwd`/tmp-glibc/sysroots/x86_64-linux/usr/sbin/:$PATH; export TPM_PATH=`pwd`/my-machine/myvtpm0; swtpm_cuse -n vtpm0' && sudo chmod a+rw /dev/vtpm0
- run qemu:
$ runqemu 'qemuparams=-tpmdev cuse-tpm,id=tpm0,path=/dev/vtpm0 -device tpm-tis,tpmdev=tpm0' ...
The guest kernel has to have TPM support enabled, which can be done with:
KERNEL_FEATURES_append = " features/tpm/tpm.scc"
(From OE-Core rev: 1264d26fa251ac11a9069f3e602dec6be9d8b9ba)
Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
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