Bug 1327947

Summary: [RFE] enable TPM passthrough at compile time (qemu-kvm-rhev)
Product: Red Hat Enterprise Linux 7 Reporter: Shivraj <shipatil>
Component: qemu-kvm-rhevAssignee: Marc-Andre Lureau <marcandre.lureau>
Status: CLOSED WONTFIX QA Contact: yduan
Severity: medium Docs Contact:
Priority: medium    
Version: 7.2CC: areis, chayang, creynold, cww, dzheng, fmartine, jcoscia, jinzhao, juzhang, kchamart, knoel, lersek, marcandre.lureau, michen, mkalinin, mtessun, pgozart, psztoch, rbalakri, rdoty, shipatil, virt-maint, xfu, yuhuang
Target Milestone: rcKeywords: FutureFeature, OtherQA
Target Release: 7.5   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Enhancement
Doc Text:
Story Points: ---
Clone Of:
: 1519013 1654486 (view as bug list) Environment:
Last Closed: 2018-05-03 14:03:47 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 1298243, 1359862, 1420851, 1431788, 1431790, 1431792, 1473733, 1519016, 1546815, 1558125, 1595018, 1654486, 1654490, 1668199, 1919797    

Description Shivraj 2016-04-18 06:39:10 UTC
Description of problem:
Downstream qemu-kvm does not support the TPM configuration for pass-through devices.

Version-Release number of selected component (if applicable):
qemu-kvm-1.5.3-105.el7_2.3.x86_64

How reproducible:

Steps to Reproduce:
On RHEL 7.2

1. For KVM guest define a TPM passthrough device as per 
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Virtualization_Deployment_and_Administration_Guide/sect-Manipulating_the_domain_xml-Devices.html#sect-Devices-TPM_devices

2. Snip of gues XML definition
---
<tpm model='tpm-tis'>
<backend type='passthrough'>
<device path='/dev/tpm0'/>
</backend> </tpm>
---

3. Start the guest.

Actual results:
Guest fails to start with bellow error:
...
Error starting domain: unsupported configuration: The QEMU executable /usr/libexec/qemu-kvm does not support TPM backend type passthrough
Traceback (most recent call last):
File "/usr/share/virt-manager/virtManager/asyncjob.py", line 89, in cb_wrapper
    callback(asyncjob, *args, **kwargs)
File "/usr/share/virt-manager/virtManager/asyncjob.py", line 125, in tmpcb
    callback(*args, **kwargs)
File "/usr/share/virt-manager/virtManager/libvirtobject.py", line 83, in newfn
    ret = fn(self, *args, **kwargs)
File "/usr/share/virt-manager/virtManager/domain.py", line 1433, in startup
    self._backend.create()
File "/usr/lib64/python2.7/site-packages/libvirt.py", line 1029, in create
    if ret == -1: raise libvirtError ('virDomainCreate() failed', dom=self)
libvirtError: unsupported configuration: The QEMU executable /usr/libexec/qemu-kvm does not support TPM backend type passthrough
...

Expected results:
Guest should start normally.


Additional info:

On RHEL 7.2

# rpm -q qemu-kvm
qemu-kvm-1.5.3-105.el7_2.3.x86_64
# /usr/libexec/qemu-kvm --help | grep -i tpm
<no output>

On Fedora 23

# rpm -q qemu-kvm
qemu-kvm-2.4.1-8.fc23.x86_64
# /usr/bin/qemu-kvm --help | grep -i tpm
TPM device options: -tpmdev passthrough,id=id[,path=path][,cancel-path=path]
            use path to provide path to a character device; default is /dev/tpm0
            use cancel-path to provide path to TPM's cancel sysfs entry;
            if not provided it will be searched for in /sys/class/misc/tpm?/device

Installed tpl-tools package.

# ls -al /lib/modules/$(uname -r)/kernel/drivers/char/tpm
total 128
drwxr-xr-x. 2 root root 4096 Apr 2 16:08 .
drwxr-xr-x. 5 root root 4096 Apr 2 16:08 ..
-rw-r--r--. 1 root root 11241 Mar 1 03:55 tpm_atmel.ko
-rw-r--r--. 1 root root 12097 Mar 1 03:55 tpm_crb.ko
-rw-r--r--. 1 root root 11793 Mar 1 03:55 tpm_i2c_atmel.ko
-rw-r--r--. 1 root root 16121 Mar 1 03:55 tpm_i2c_infineon.ko
-rw-r--r--. 1 root root 21857 Mar 1 03:55 tpm_i2c_nuvoton.ko
-rw-r--r--. 1 root root 25225 Mar 1 03:55 tpm_infineon.ko
-rw-r--r--. 1 root root 15969 Mar 1 03:55 tpm_nsc.ko

# tpm_version
TPM 1.2 Version Info:
Chip Version: 1.2.6.40
Spec Level: 2
Errata Revision: 3
TPM Vendor ID: IFX
Vendor Specific data: 062800be 0074706d 733038ff ff
TPM Version: 01010000
Manufacturer Info: 49465800

Comment 11 Ademar Reis 2017-03-13 18:43:38 UTC
*** Bug 1427894 has been marked as a duplicate of this bug. ***

Comment 15 Ademar Reis 2017-09-18 13:13:46 UTC
*** Bug 1314816 has been marked as a duplicate of this bug. ***

Comment 21 Russell Doty 2018-02-20 14:46:10 UTC
Updated information:

The TPM2 userspace tools as of RHEL 7.5 (Tech Preview in RHEL 7.4) include a resource manager that allows multiple users to interact with a TPM. Multiple keys and key hierarchies can be used. The actual keys are stored on disk as encrypted blobs and loaded and unloaded as needed.

It should be possible to design and implement qemu support such that each VM appears to have its own TPM, including unique set of keys and measurements.

This is not a straight TPM passthrough for the physical TPM, but would meet the requirements for multiple guests using bitlocker and measured boot.

Is this direction worth exploring?