Re: [Qemu-devel] TPM does not seem to work under QEMU with TPM patches

[Stefan Berger <stefanb@linux.vnet.ibm.com>]

On 08/20/2012 06:12 PM, Jordi Cucurull Juan wrote:
> Dear all,
>
> I am testing the TPM patches of Stefan Berger to provide TPM support 
> to QEMU. Nevertheless I have not managed to run them successfully. 
> During the compilation of QEMU with his patches (V18 for revision 
> 563987d) I have not had any issue. But, I have a virtual machine based 
> on CentOS 6.2 and the TPM does not seem to be present. I run the 
> machine with the following command line (as a root user):
>
> # /usr/local/bin/qemu-system-x86_64 -hda qemu-disk-centos.img -m 1024 
> -boot d -enable-kvm -usbdevice tablet -k es -tpmdev 
> passthrough,id=tpm0,path=/dev/tpm0 -device tpm-tis,tpmdev=tpm0
>
> My real machine has an Infineon TPM v1.2. When I try to load the TSS 
> library (Trousers) inside the client machine (the CentOS 6.2) it 
> throws the following error:
>
> insmod: error inserting 
> '/lib/modules/2.6.32-279.5.1.el6.x86_64/kernel/drivers/char/tpm/tpm_atmel.ko': 
> -1 no such device
>
You have to use tpm_tis.
Unless you are using the SeaBIOS extensions for TPM support as well you 
have do

modprobe tpm_tis force=1

or in the grub command line

tpm_tis.force=1

The 'force' parameter is necessary if ACPI tables for TPM are missing 
and those are only provided once SeaBIOS has been patched with TPM support.


      Stefan

> Apart from this, QEMU does not throw any error. Should I enable 
> something else to have access to the TPM? In addition, I do not see 
> any /dev/vtpm0 device in my real machine.
>
>
> Best regards,
> Jordi.
>
>