Xen project Mailing List

2013/6/6 Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>

On 06/05/2013 10:57 PM, Bei Guan wrote:
[... cropping and moving the config below ...]

I have applied your patch tpmfront (v3) to the linux-kernel 3.9.1.
When I create the vtpm_manager, there is an error as the following. (on
Xen-4.3-unstable with TPM emulator)
Does this error has something to do with the TPM emulator?
(PS: I have not yet changed the vtpm manager and vtpm to fit for the
emulator.)

[root@localhost vtpm-conf]# xl create -c vtpmmgr-stubdom.cfg
Parsing config from vtpmmgr-stubdom.cfg
Daemon running with PID 6631
Xen Minimal OS!
start_info: 0xa3000(VA)
nr_pages: 0x1000
shared_inf: 0xbbcaf000(MA)
pt_base: 0xa6000(VA)
nr_pt_frames: 0x5
mfn_list: 0x9b000(VA)
mod_start: 0x0(VA)
mod_len: 0
flags: 0x0
cmd_line:
stack: 0x5a7a0-0x7a7a0
MM: Init
_text: 0x0(VA)
_etext: 0x39854(VA)
_erodata: 0x46000(VA)
_edata: 0x48c00(VA)
stack start: 0x5a7a0(VA)
_end: 0x9adc0(VA)
start_pfn: ae
max_pfn: 1000
Mapping memory range 0x400000 - 0x1000000
setting 0x0-0x46000 readonly
skipped 0x1000
MM: Initialise page allocator for b4000(b4000)-1000000(1000000)
MM: done
Demand map pfns at 1001000-2001001000.
Heap resides at 2001002000-4001002000.
Initialising timer interface
Initialising console ... done.
gnttab_table mapped at 0x1001000.
Initialising scheduler
Thread "Idle": pointer: 0x2001002050, stack: 0xd0000
Thread "xenstore": pointer: 0x2001002800, stack: 0xe0000
xenbus initialised on irq 1 mfn 0x1003e8
Thread "shutdown": pointer: 0x2001002fb0, stack: 0xf0000
Dummy main: start_info=0x7a8a0
Thread "main": pointer: 0x2001003760, stack: 0x100000
"main"
Shutting down ()
Shutdown requested: 3
Thread "shutdown" exited.
INFO[VTPM]: Starting vTPM manager domain
INFO[VTPM]: Option: Using tpm_tis driver
******************* BLKFRONT for device/vbd/768 **********

backend at /local/domain/0/backend/qdisk/19/768
Failed to read /local/domain/0/backend/qdisk/19/768/feature-barrier.
32768 sectors of 512 bytes
**************************
blk_open(device/vbd/768) -> 3
============= Init TPM BACK ================
Thread "tpmback-listener": pointer: 0x20010043f0, stack: 0xf0000
============= Init TPM TIS Driver ==============
IOMEM Machine Base Address: FED40000
Enabled Localities: 0
Map 1 (fed40, ...) at 0x1006000 failed: -1.

This seems to be a failure to map the I/O memory for the physical TPM.

Do_exit called!
base is 0x10fcb8 caller is 0x1f0ea
base is 0x10fcd8 caller is 0x284e3
base is 0x10fd88 caller is 0x285b8
base is 0x10fde8 caller is 0x270cc
base is 0x10fe28 caller is 0x270e4
base is 0x10fe38 caller is 0x1bcc9
base is 0x10fe78 caller is 0x6ffc
base is 0x10ff38 caller is 0x3545
base is 0x10ff68 caller is 0x1fc1c
base is 0x10ffe8 caller is 0x343b

The config file for vTPM manager is

kernel="/root/Xen/xen-4.3-unstable/stubdom/mini-os-x86_64-vtpmmgr/mini-os.gz"
memory=16
disk=["file:/var/vtpmmgr-stubdom.img,hda,w"]
name="vtpmmgr"
iomem=["fed40,5"]

The iomem line here should allow the TPM to be mapped without this error. Is
this on a system with a hardware TPM? If not, then that would explain the
error.

2013/6/4 Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>

On 06/04/2013 05:03 AM, Bei Guan wrote:

2013/5/29 Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>

On 05/29/2013 07:23 AM, Bei Guan wrote:

Thank you for all your reply. I'll try vTPM on Xen-4.3-unstable.

However, I don't have a physical TPM on my PC. Can I use the TPM
emulator
in Xen-4.3-unstable now?

Thank you very much,
Bei Guan

The current TPM Manager requires a physical TPM to be present.
While

you could make things work without one, it would require patching
either the vTPM or vTPM Manager domains with an alternate sealing
mechanism for the long-term keys and source of random numbers.

Hi Daniel,

I'm trying vTPM on Xen-4.3-unstable with a TPM emulator. However, I run
into problems.
Everything in stubdom seems to be compiled successfully except for the
TPM
emulator.

I can't help if I don't know what the problems are. Some of the
dependencies
in stubdom may be broken if you got things half-compiled before they
broke,
so a clean tree could help. You also need cmake, but it sounds like
you've
gotten past that point.

I'm not sure how to make the TPM emulator work in Xen-4.3. Can you
give me

more detailed instructions? Such as which part of the code need to be
modified, if necessary. And, how much the coding work need to do to
make
the TPM emulator work?

The TPM emulator (vtpm-stubdom) depends on the TPM Manager
(vtpmmgr-stubdom)
to store its encryption keys securely. The TPM Manager uses a physical
TPM
to secure its own storage. Without a physical TPM, this is not
possible, so
possible workarounds include removing the requirement to have a TPM
manager
from the vTPM domain (remove tpmfront references), or to modify the TPM
manager to not use the physical TPM.

In either case, you will need to find another source for random numbers,
which is one thing the physical TPM is used for. Changing the vTPM
would be
simpler than changing the TPM manager; the code you need to change is
~1000
lines, but most of your changes will be removal of code.

I found there is a code file tpm_tis.c in mini-os/ and
stubdom/ioemu/hw/

respectively. What's the difference between them? Is the code
stubdom/ioemu/hw/tpm_tis.c only for QEMU emulated TPM device?
And, what's the difference between mini-os/tpm_tis.c and
drivers/char/tpm/tpm_tis.c in linux kernel?

Thank you very much.

The mini-os driver is derived from the one in the Linux kernel; they
both
interface with a hardware TPM. The QEMU code (ioemu/hw) emulates a
hardware
TPM based on qemu's access to a Linux /dev/tpm0 device driver. With
Linux
stub domains, this device can be backed by the tpmfront driver
connected to
the vtpm stubdom.

--
Daniel De Graaf
National Security Agency

--
Best Regards,

Bei Guan

Re: [Xen-devel] Install vTPM on Xen-4.2.2