Add a TPM Passthrough backend driver implementation
This patch is based of off version 9 of Stefan Berger's patch series
"QEMU Trusted Platform Module (TPM) integration"
and adds a new backend driver for it.
This patch adds a passthrough backend driver for passing commands sent to the
emulated TPM device directly to a TPM device opened on the host machine.
Thus it is possible to use a hardware TPM device in a system running on QEMU,
providing the ability to access a TPM in a special state (e.g. after a Trusted
Boot).
This functionality is being used in the acTvSM Trusted Virtualization Platform
which is available on [1].
Usage example:
qemu-system-x86_64 -tpmdev passthrough,id=tpm0,path=/dev/tpm0 \
-device tpm-tis,tpmdev=tpm0 \
-cdrom test.iso -boot d
Some notes about the host TPM:
The TPM needs to be enabled and activated. If that's not the case one
has to go through the BIOS/UEFI and enable and activate that TPM for TPM
commands to work as expected.
It may be necessary to boot the kernel using tpm_tis.force=1 in the boot
command line or 'modprobe tpm_tis force=1' in case of using it as a module.
Regards,
Andreas Niederl, Stefan Berger
[1] http://trustedjava.sourceforge.net/
Signed-off-by: Andreas Niederl <andreas.niederl@iaik.tugraz.at>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Corey Bryant <coreyb@linux.vnet.ibm.com>
Reviewed-by: Joel Schopp <jschopp@linux.vnet.ibm.com>
Message-id: 1361987275-26289-6-git-send-email-stefanb@linux.vnet.ibm.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/qemu-char.c b/qemu-char.c
index 04aa589..83787c7 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -533,6 +533,30 @@
}
return len1 - len;
}
+
+int recv_all(int fd, void *_buf, int len1, bool single_read)
+{
+ int ret, len;
+ uint8_t *buf = _buf;
+
+ len = len1;
+ while ((len > 0) && (ret = read(fd, buf, len)) != 0) {
+ if (ret < 0) {
+ if (errno != EINTR && errno != EAGAIN) {
+ return -1;
+ }
+ continue;
+ } else {
+ if (single_read) {
+ return ret;
+ }
+ buf += ret;
+ len -= ret;
+ }
+ }
+ return len1 - len;
+}
+
#endif /* !_WIN32 */
typedef struct IOWatchPoll