Re: [PATCH v4 1/3] docs: Add support for TPM devices over I2C bus

[Ninad Palsule]

On 3/25/23 11:10 AM, Stefan Berger wrote:

On 3/25/23 00:37, Ninad Palsule wrote:

This is a documentation change for I2C TPM device support.

Qemu already supports devices attached to ISA and sysbus.
This drop adds support for the I2C bus attached TPM devices.

Signed-off-by: Ninad Palsule <ni...@linux.ibm.com>

---
V2:

Incorporated Stephen's review comments
- Added example in the document.

---
V4:
Incorporate Cedric & Stefan's comments

- Added example for ast2600-evb
- Corrected statement about arm virtual machine.
---
  docs/specs/tpm.rst | 32 ++++++++++++++++++++++++++++++++
  1 file changed, 32 insertions(+)

diff --git a/docs/specs/tpm.rst b/docs/specs/tpm.rst
index 535912a92b..a0600e2834 100644
--- a/docs/specs/tpm.rst
+++ b/docs/specs/tpm.rst
@@ -21,12 +21,16 @@ QEMU files related to TPM TIS interface:
   - ``hw/tpm/tpm_tis_common.c``
   - ``hw/tpm/tpm_tis_isa.c``
   - ``hw/tpm/tpm_tis_sysbus.c``
+ - ``hw/tpm/tpm_tis_i2c.c``
   - ``hw/tpm/tpm_tis.h``
    Both an ISA device and a sysbus device are available. The former is
  used with pc/q35 machine while the latter can be instantiated in the
  Arm virt machine.

  +An I2C device support is also added which can be instantiated in the armadded -> provided

arm -> Arm

Done

+based emulation machines. This device only supports the TPM 2 protocol.
+
  CRB interface
  -------------

  @@ -348,6 +352,34 @@ In case an Arm virt machine is emulated, use the following command line:

      -drive if=pflash,format=raw,file=flash0.img,readonly=on \
      -drive if=pflash,format=raw,file=flash1.img

  +In case a ast2600-evb bmc machine is emulated and want to use TPM device

+attached to I2C bus, use the following command line:
+
+.. code-block:: console
+
+  qemu-system-arm -M ast2600-evb -nographic \
+    -kernel arch/arm/boot/zImage \
+    -dtb arch/arm/boot/dts/aspeed-ast2600-evb.dtb \
+    -initrd rootfs.cpio \
+    -chardev socket,id=chrtpm,path=/tmp/mytpm1/swtpm-sock \
+    -tpmdev emulator,id=tpm0,chardev=chrtpm \
+    -device tpm-tis-i2c,tpmdev=tpm0,bus=aspeed.i2c.bus.12,address=0x2e
+
+In case a Rainier bmc machine is emulated and want to use TPM device
+attached to I2C bus, use the following command line:
+
+.. code-block:: console
+
+  qemu-system-arm -M rainier-bmc -nographic \
+    -kernel ${IMAGEPATH}/fitImage-linux.bin \
+    -dtb ${IMAGEPATH}/aspeed-bmc-ibm-rainier.dtb \
+    -initrd ${IMAGEPATH}/obmc-phosphor-initramfs.rootfs.cpio.xz \

+    -drive file=${IMAGEPATH}/obmc-phosphor-image.rootfs.wic.qcow2,if=sd,index=2\ +    -net nic -net user,hostfwd=:127.0.0.1:2222-:22,hostfwd=:127.0.0.1:2443-:443\

+    -chardev socket,id=chrtpm,path=/tmp/mytpm1/swtpm-sock \
+    -tpmdev emulator,id=tpm0,chardev=chrtpm \
+    -device tpm-tis-i2c,tpmdev=tpm0,bus=aspeed.i2c.bus.12,address=0x2e
+
  In case SeaBIOS is used as firmware, it should show the TPM menu item
  after entering the menu with 'ESC'.

With the above nits:

Reviewed-by: Stefan Berger <stef...@linux.ibm.com>