If the requested buffer size of the frontend is smaller than the fixed
buffer size of the host's TPM, fail the startup_tpm() interface function,
which will make the device unusable. We fail it because the backend TPM
could produce larger packets than what the frontend could pass to the OS.
The current combination of TIS frontend and either passthrough or emulator
backend will not lead to this case since the TIS can support any size of
buffer.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Convert the tpm_emulator backend to get the current buffer size
of the external device and set it to the buffer size that the
frontend (TIS) requests.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Rather than hard coding the buffer size in the tpm_passthrough
backend read the TPM I/O buffer size from the host device.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Rather than setting the size of the TPM buffer in the front-end,
query the backend for the size of the buffer. In this patch we
just move the hard-coded buffer size of 4096 to the backends.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
The reported error message is already prefixed with the -device
name & arguments.
Before:
qemu-system-x86_64: -device tpm-tis,id=foo,tpmdev=foo,irq=21: tpm_tis: IRQ 21 is outside valid range of 0 to 15
After:
qemu-system-x86_64: -device tpm-tis,id=foo,tpmdev=foo,irq=21: IRQ 21 is outside valid range of 0 to 15
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
The TPM backend processing thread has common shared variable race
issues. (they should not be so easy to reach since guest interaction
with the device is slow compared to host emulation)
An obvious one is setting op_cancelled from device thread after
calling write(cancel_fd). The backend thread may return before the
device thread has set the variable. Instead set it before
cancellation. Even if the write() failed, the end result is command
get possibly cancelled (even if cancellation came from external
sources it doesn't matter much).
It's worth to consider removing the backend processing thread for now.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
The value is later unneeded, and may leak if the free visitor doesn't
consider it since has_cancel_path is false. And for consistency with
"path" it shouldn't be returned in get_tpm_options().
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Lift from the backend implementation the responsability to call the
request_completed() callback outside of thread context. This also
simplify frontend/interface work, as they no longer need to care
whether the callback is called from a different thread.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Store the TPM interface, the actual object may be different from
TPMState. Keep a reference on the interface, and check the backend
wasn't already initialized.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Rather than returning ~0, return 0 for every register in case of failure
mode. The '0' is better to indicate that there's no device there. It avoids
SeaBIOS detecting a device and getting stuck on it trying to read and write
its registers.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
In case the backend has a failure, such as the tpm_emulator's CMD_INIT
failing, the TIS goes into failure mode and does not respond to reads
or writes to MMIO registers. In this case we need to prevent the ACPI
table from being added and the straight-forward way is to indicate that
there's no known TPM version being used.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
The control chardev is being used from the data thread to set the
locality of the next request. Altough the chr has a write mutex, we
may potentially read the reply from another thread request.
Add a mutex to protect from concurrent control commands.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
This will simplify backend / interface objects relationship, so the
frontend interface will simply have to implement the TPM QOM interface.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
The previous patch cleaned up a bit error handling, and exposed an
existing bug: error_report_err() could be called with a NULL error.
Instead, make tpm_emulator_set_locality() set the error.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
This change introduces a new TPM backend driver that can communicate with
swtpm(software TPM emulator) using unix domain socket interface. QEMU talks to
the TPM emulator using QEMU's socket-based chardev backend device.
Swtpm uses two Unix sockets for communications, one for plain TPM commands and
responses, and one for out-of-band control messages. QEMU passes the data
socket to be used over the control channel.
The swtpm and associated tools can be found here:
https://github.com/stefanberger/swtpm
The swtpm's control channel protocol specification can be found here:
https://github.com/stefanberger/swtpm/wiki/Control-Channel-Specification
Usage:
# setup TPM state directory
mkdir /tmp/mytpm
chown -R tss:root /tmp/mytpm
/usr/bin/swtpm_setup --tpm-state /tmp/mytpm --createek
# Ask qemu to use TPM emulator with given tpm state directory
qemu-system-x86_64 \
[...] \
-chardev socket,id=chrtpm,path=/tmp/swtpm-sock \
-tpmdev emulator,id=tpm0,chardev=chrtpm \
-device tpm-tis,tpmdev=tpm0 \
[...]
Signed-off-by: Amarnath Valluri <amarnath.valluri@intel.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
