Add linux,sml-log, which carries the firmware TPM log in a uint8-array, to
the properties. Either this property is required or both linux,sml-base and
linux,sml-size are required. Add a test case for verification.
Fixes: 82003e0487fb ("Documentation: tpm: add the IBM Virtual TPM device tree binding documentation")
Cc: Lukas Wunner <[email protected]>
Cc: Nayna Jain <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Signed-off-by: Stefan Berger <[email protected]>
---
.../devicetree/bindings/tpm/ibm,vtpm.yaml | 20 +++++++++++++++++--
.../devicetree/bindings/tpm/tpm-common.yaml | 14 ++++++++++++-
2 files changed, 31 insertions(+), 3 deletions(-)
diff --git a/Documentation/devicetree/bindings/tpm/ibm,vtpm.yaml b/Documentation/devicetree/bindings/tpm/ibm,vtpm.yaml
index 50a3fd31241c..8885ef3b7638 100644
--- a/Documentation/devicetree/bindings/tpm/ibm,vtpm.yaml
+++ b/Documentation/devicetree/bindings/tpm/ibm,vtpm.yaml
@@ -74,8 +74,6 @@ required:
- ibm,my-dma-window
- ibm,my-drc-index
- ibm,loc-code
- - linux,sml-base
- - linux,sml-size
allOf:
- $ref: tpm-common.yaml#
@@ -102,3 +100,21 @@ examples:
linux,sml-size = <0xbce10200>;
};
};
+ - |
+ soc {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ tpm@30000003 {
+ compatible = "IBM,vtpm20";
+ device_type = "IBM,vtpm";
+ reg = <0x30000003>;
+ interrupts = <0xa0003 0x0>;
+ ibm,#dma-address-cells = <0x2>;
+ ibm,#dma-size-cells = <0x2>;
+ ibm,my-dma-window = <0x10000003 0x0 0x0 0x0 0x10000000>;
+ ibm,my-drc-index = <0x30000003>;
+ ibm,loc-code = "U9080.HEX.134CA08-V7-C3";
+ linux,sml-log = <00 00 00 00 03 00 00>;
+ };
+ };
diff --git a/Documentation/devicetree/bindings/tpm/tpm-common.yaml b/Documentation/devicetree/bindings/tpm/tpm-common.yaml
index 3c1241b2a43f..f6f0b551268c 100644
--- a/Documentation/devicetree/bindings/tpm/tpm-common.yaml
+++ b/Documentation/devicetree/bindings/tpm/tpm-common.yaml
@@ -30,6 +30,11 @@ properties:
size of reserved memory allocated for firmware event log
$ref: /schemas/types.yaml#/definitions/uint32
+ linux,sml-log:
+ description:
+ Content of firmware event log
+ $ref: /schemas/types.yaml#/definitions/uint8-array
+
memory-region:
description: reserved memory allocated for firmware event log
maxItems: 1
@@ -53,15 +58,22 @@ dependentRequired:
linux,sml-base: ['linux,sml-size']
linux,sml-size: ['linux,sml-base']
-# must only have either memory-region or linux,sml-base
+# must only have either memory-region or linux,sml-base/size or linux,sml-log
# as well as either resets or reset-gpios
dependentSchemas:
memory-region:
properties:
linux,sml-base: false
+ linux,sml-log: false
linux,sml-base:
properties:
memory-region: false
+ linux,sml-log: false
+ linux,sml-log:
+ properties:
+ memory-region: false
+ linux,sml-base: false
+ linux,sml-size: false
resets:
properties:
reset-gpios: false
--
2.43.0
On Mon, Mar 11, 2024 at 09:20:29AM -0400, Stefan Berger wrote:
> Add linux,sml-log, which carries the firmware TPM log in a uint8-array, to
> the properties. Either this property is required or both linux,sml-base and
> linux,sml-size are required. Add a test case for verification.
>
> Fixes: 82003e0487fb ("Documentation: tpm: add the IBM Virtual TPM device tree binding documentation")
The Fixes tag is confusing. The patch won't even apply cleanly to the
v4.10 commit referenced here as the conversion to yaml happened only
recently with v6.8.
Why is the Fixes tag necessary in the first place? Same question for
the other patches in the series. This looks like feature work rather
than a fix. Not sure whether it satisfies the "obviously correct"
rule per Documentation/process/stable-kernel-rules.rst.
> --- a/Documentation/devicetree/bindings/tpm/ibm,vtpm.yaml
> +++ b/Documentation/devicetree/bindings/tpm/ibm,vtpm.yaml
> @@ -74,8 +74,6 @@ required:
> - ibm,my-dma-window
> - ibm,my-drc-index
> - ibm,loc-code
> - - linux,sml-base
> - - linux,sml-size
I assume that either these two or the new "linux,sml-log" property
are (still) required? If so, a quick grep through the bindings
(e.g. auxdisplay/img,ascii-lcd.yaml) shows that the following
might work:
required:
- ...
oneOf:
- required:
- linux,sml-base
- required:
- linux,sml-log
> --- a/Documentation/devicetree/bindings/tpm/tpm-common.yaml
> +++ b/Documentation/devicetree/bindings/tpm/tpm-common.yaml
> @@ -30,6 +30,11 @@ properties:
> size of reserved memory allocated for firmware event log
> $ref: /schemas/types.yaml#/definitions/uint32
>
> + linux,sml-log:
> + description:
> + Content of firmware event log
Please add one or two sentences of context so that readers don't
need to use git blame + git log to find out what this is for.
(Mention at least that the property may be used to pass the log
to a kexec kernel.)
> -# must only have either memory-region or linux,sml-base
> +# must only have either memory-region or linux,sml-base/size or linux,sml-log
> # as well as either resets or reset-gpios
> dependentSchemas:
> memory-region:
> properties:
> linux,sml-base: false
> + linux,sml-log: false
> linux,sml-base:
> properties:
> memory-region: false
> + linux,sml-log: false
> + linux,sml-log:
> + properties:
> + memory-region: false
> + linux,sml-base: false
> + linux,sml-size: false
Could you add "linux,sml-size: false" to "memory-region" as well
while at it for consistency?
Thanks,
Lukas
On 3/12/24 07:11, Lukas Wunner wrote:
> On Mon, Mar 11, 2024 at 09:20:29AM -0400, Stefan Berger wrote:
>> Add linux,sml-log, which carries the firmware TPM log in a uint8-array, to
>> the properties. Either this property is required or both linux,sml-base and
>> linux,sml-size are required. Add a test case for verification.
>>
>> Fixes: 82003e0487fb ("Documentation: tpm: add the IBM Virtual TPM device tree binding documentation")
>
> The Fixes tag is confusing. The patch won't even apply cleanly to the
> v4.10 commit referenced here as the conversion to yaml happened only
> recently with v6.8.
Then that's as far back (6.8) as the series may be applied. I put the
Fixes tag on the first appearance of sml-base/sml-size since for kexec
this was never correct.
>
> Why is the Fixes tag necessary in the first place? Same question for
> the other patches in the series. This looks like feature work rather
> than a fix. Not sure whether it satisfies the "obviously correct"
> rule per Documentation/process/stable-kernel-rules.rst.
It is a fix for the interaction of the TPM firmware log with kexec. The
sml-base buffer pointer was never protected across a kexec.
>
>
>> --- a/Documentation/devicetree/bindings/tpm/ibm,vtpm.yaml
>> +++ b/Documentation/devicetree/bindings/tpm/ibm,vtpm.yaml
>> @@ -74,8 +74,6 @@ required:
>> - ibm,my-dma-window
>> - ibm,my-drc-index
>> - ibm,loc-code
>> - - linux,sml-base
>> - - linux,sml-size
>
> I assume that either these two or the new "linux,sml-log" property
> are (still) required? If so, a quick grep through the bindings
> (e.g. auxdisplay/img,ascii-lcd.yaml) shows that the following
> might work:
>
> required:
> - ...
>
> oneOf:
> - required:
> - linux,sml-base
> - required:
> - linux,sml-log
>
You're right, they need to be here since examples could now omit
sml-base or sml-log. I added them. Thanks.
>
>> --- a/Documentation/devicetree/bindings/tpm/tpm-common.yaml
>> +++ b/Documentation/devicetree/bindings/tpm/tpm-common.yaml
>> @@ -30,6 +30,11 @@ properties:
>> size of reserved memory allocated for firmware event log
>> $ref: /schemas/types.yaml#/definitions/uint32
>>
>> + linux,sml-log:
>> + description:
>> + Content of firmware event log
>
> Please add one or two sentences of context so that readers don't
> need to use git blame + git log to find out what this is for.
> (Mention at least that the property may be used to pass the log
> to a kexec kernel.)
Ok, will do:
Content of firmware event log embedded in device tree to be safely
carried across a kexec soft reboot.
>
>
>> -# must only have either memory-region or linux,sml-base
>> +# must only have either memory-region or linux,sml-base/size or linux,sml-log
>> # as well as either resets or reset-gpios
>> dependentSchemas:
>> memory-region:
>> properties:
>> linux,sml-base: false
>> + linux,sml-log: false
>> linux,sml-base:
>> properties:
>> memory-region: false
>> + linux,sml-log: false
>> + linux,sml-log:
>> + properties:
>> + memory-region: false
>> + linux,sml-base: false
>> + linux,sml-size: false
>
> Could you add "linux,sml-size: false" to "memory-region" as well
> while at it for consistency?
Done. Thanks.
Stefan
>
> Thanks,
>
> Lukas
On Tue Mar 12, 2024 at 1:11 PM EET, Lukas Wunner wrote:
> On Mon, Mar 11, 2024 at 09:20:29AM -0400, Stefan Berger wrote:
> > Add linux,sml-log, which carries the firmware TPM log in a uint8-array, to
> > the properties. Either this property is required or both linux,sml-base and
> > linux,sml-size are required. Add a test case for verification.
> >
> > Fixes: 82003e0487fb ("Documentation: tpm: add the IBM Virtual TPM device tree binding documentation")
>
> The Fixes tag is confusing. The patch won't even apply cleanly to the
> v4.10 commit referenced here as the conversion to yaml happened only
> recently with v6.8.
>
> Why is the Fixes tag necessary in the first place? Same question for
> the other patches in the series. This looks like feature work rather
> than a fix. Not sure whether it satisfies the "obviously correct"
> rule per Documentation/process/stable-kernel-rules.rst.
I'm not yet sure whether these are bug fixes and or improvements because
I did not fully understand the scenario where TPM corrupts the event log
so that part reminds to be seen.
Probably once I fully understand what is going on, it is possible to
argue on that.
BR, Jarkko