diff mbox series

[v9,2/2] tpm: Add support for event log pointer found in TPM2 ACPI table

Message ID 20200706181953.3592084-3-stefanb@linux.vnet.ibm.com (mailing list archive)
State New, archived
Headers show
Series tpm2: Make TPM2 logs accessible for non-UEFI firmware | expand

Commit Message

Stefan Berger July 6, 2020, 6:19 p.m. UTC 
From: Stefan Berger <stefanb@linux.ibm.com>

In case a TPM2 is attached, search for a TPM2 ACPI table when trying
to get the event log from ACPI. If one is found, use it to get the
start and length of the log area. This allows non-UEFI systems, such
as SeaBIOS, to pass an event log when using a TPM2.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
---
 drivers/char/tpm/eventlog/acpi.c | 63 +++++++++++++++++++++-----------
 1 file changed, 42 insertions(+), 21 deletions(-)

Comments

Jerry Snitselaar July 6, 2020, 10:04 p.m. UTC | #1 
Stefan Berger @ 2020-07-06 11:19 MST:

> From: Stefan Berger <stefanb@linux.ibm.com>
>
> In case a TPM2 is attached, search for a TPM2 ACPI table when trying
> to get the event log from ACPI. If one is found, use it to get the
> start and length of the log area. This allows non-UEFI systems, such
> as SeaBIOS, to pass an event log when using a TPM2.
>
> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>

Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>

> ---
>  drivers/char/tpm/eventlog/acpi.c | 63 +++++++++++++++++++++-----------
>  1 file changed, 42 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/char/tpm/eventlog/acpi.c b/drivers/char/tpm/eventlog/acpi.c
> index 63ada5e53f13..3633ed70f48f 100644
> --- a/drivers/char/tpm/eventlog/acpi.c
> +++ b/drivers/char/tpm/eventlog/acpi.c
> @@ -49,9 +49,9 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
>  	void __iomem *virt;
>  	u64 len, start;
>  	struct tpm_bios_log *log;
> -
> -	if (chip->flags & TPM_CHIP_FLAG_TPM2)
> -		return -ENODEV;
> +	struct acpi_table_tpm2 *tbl;
> +	struct acpi_tpm2_phy *tpm2_phy;
> +	int format;
>  
>  	log = &chip->log;
>  
> @@ -61,23 +61,44 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
>  	if (!chip->acpi_dev_handle)
>  		return -ENODEV;
>  
> -	/* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
> -	status = acpi_get_table(ACPI_SIG_TCPA, 1,
> -				(struct acpi_table_header **)&buff);
> -
> -	if (ACPI_FAILURE(status))
> -		return -ENODEV;
> -
> -	switch(buff->platform_class) {
> -	case BIOS_SERVER:
> -		len = buff->server.log_max_len;
> -		start = buff->server.log_start_addr;
> -		break;
> -	case BIOS_CLIENT:
> -	default:
> -		len = buff->client.log_max_len;
> -		start = buff->client.log_start_addr;
> -		break;
> +	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
> +		status = acpi_get_table("TPM2", 1,
> +					(struct acpi_table_header **)&tbl);
> +		if (ACPI_FAILURE(status))
> +			return -ENODEV;
> +
> +		if (tbl->header.length <
> +				sizeof(*tbl) + sizeof(struct acpi_tpm2_phy))
> +			return -ENODEV;
> +
> +		tpm2_phy = (void *)tbl + sizeof(*tbl);
> +		len = tpm2_phy->log_area_minimum_length;
> +
> +		start = tpm2_phy->log_area_start_address;
> +		if (!start || !len)
> +			return -ENODEV;
> +
> +		format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
> +	} else {
> +		/* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
> +		status = acpi_get_table(ACPI_SIG_TCPA, 1,
> +					(struct acpi_table_header **)&buff);
> +		if (ACPI_FAILURE(status))
> +			return -ENODEV;
> +
> +		switch (buff->platform_class) {
> +		case BIOS_SERVER:
> +			len = buff->server.log_max_len;
> +			start = buff->server.log_start_addr;
> +			break;
> +		case BIOS_CLIENT:
> +		default:
> +			len = buff->client.log_max_len;
> +			start = buff->client.log_start_addr;
> +			break;
> +		}
> +
> +		format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
>  	}
>  	if (!len) {
>  		dev_warn(&chip->dev, "%s: TCPA log area empty\n", __func__);
> @@ -98,7 +119,7 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
>  	memcpy_fromio(log->bios_event_log, virt, len);
>  
>  	acpi_os_unmap_iomem(virt, len);
> -	return EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
> +	return format;
>  
>  err:
>  	kfree(log->bios_event_log);
Jarkko Sakkinen July 6, 2020, 11:09 p.m. UTC | #2 
On Mon, Jul 06, 2020 at 02:19:53PM -0400, Stefan Berger wrote:
> From: Stefan Berger <stefanb@linux.ibm.com>
> 
> In case a TPM2 is attached, search for a TPM2 ACPI table when trying
> to get the event log from ACPI. If one is found, use it to get the
> start and length of the log area. This allows non-UEFI systems, such
> as SeaBIOS, to pass an event log when using a TPM2.
> 
> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>

Do you think that QEMU with TPM 1.2 emulator turned on would be a viable
way to test this?

I'm anyway more worried about breaking existing TPM 1.2 functionality
and that requires only QEMU without extras.

/Jarkko
Jarkko Sakkinen July 6, 2020, 11:12 p.m. UTC | #3 
On Tue, Jul 07, 2020 at 02:09:18AM +0300, Jarkko Sakkinen wrote:
> On Mon, Jul 06, 2020 at 02:19:53PM -0400, Stefan Berger wrote:
> > From: Stefan Berger <stefanb@linux.ibm.com>
> > 
> > In case a TPM2 is attached, search for a TPM2 ACPI table when trying
> > to get the event log from ACPI. If one is found, use it to get the
> > start and length of the log area. This allows non-UEFI systems, such
> > as SeaBIOS, to pass an event log when using a TPM2.
> > 
> > Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> 
> Do you think that QEMU with TPM 1.2 emulator turned on would be a viable
> way to test this?
> 
> I'm anyway more worried about breaking existing TPM 1.2 functionality
> and that requires only QEMU without extras.

BTW, you should cc your patches to all M- and R-entries in the
MAINTAINERS file. Please, resend this patch set version. You can add
acquired reviewed-by and tested-by tags (e.g. Jerry's) and use this tag
for the patch set: "RESEND,PATCH v9".

/Jarkko
Stefan Berger July 6, 2020, 11:55 p.m. UTC | #4 
On 7/6/20 7:09 PM, Jarkko Sakkinen wrote:
> On Mon, Jul 06, 2020 at 02:19:53PM -0400, Stefan Berger wrote:
>> From: Stefan Berger <stefanb@linux.ibm.com>
>>
>> In case a TPM2 is attached, search for a TPM2 ACPI table when trying
>> to get the event log from ACPI. If one is found, use it to get the
>> start and length of the log area. This allows non-UEFI systems, such
>> as SeaBIOS, to pass an event log when using a TPM2.
>>
>> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> Do you think that QEMU with TPM 1.2 emulator turned on would be a viable
> way to test this?


Yes.


>
> I'm anyway more worried about breaking existing TPM 1.2 functionality
> and that requires only QEMU without extras.
>
> /Jarkko
Jerry Snitselaar July 6, 2020, 11:57 p.m. UTC | #5 
Jarkko Sakkinen @ 2020-07-06 16:09 MST:

> On Mon, Jul 06, 2020 at 02:19:53PM -0400, Stefan Berger wrote:
>> From: Stefan Berger <stefanb@linux.ibm.com>
>> 
>> In case a TPM2 is attached, search for a TPM2 ACPI table when trying
>> to get the event log from ACPI. If one is found, use it to get the
>> start and length of the log area. This allows non-UEFI systems, such
>> as SeaBIOS, to pass an event log when using a TPM2.
>> 
>> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
>
> Do you think that QEMU with TPM 1.2 emulator turned on would be a viable
> way to test this?
>
> I'm anyway more worried about breaking existing TPM 1.2 functionality
> and that requires only QEMU without extras.
>
> /Jarkko

The 1.2 bits should be functionally the same as before, right?
Jarkko Sakkinen July 7, 2020, 2:24 a.m. UTC | #6 
On Mon, Jul 06, 2020 at 07:55:26PM -0400, Stefan Berger wrote:
> On 7/6/20 7:09 PM, Jarkko Sakkinen wrote:
> > On Mon, Jul 06, 2020 at 02:19:53PM -0400, Stefan Berger wrote:
> > > From: Stefan Berger <stefanb@linux.ibm.com>
> > > 
> > > In case a TPM2 is attached, search for a TPM2 ACPI table when trying
> > > to get the event log from ACPI. If one is found, use it to get the
> > > start and length of the log area. This allows non-UEFI systems, such
> > > as SeaBIOS, to pass an event log when using a TPM2.
> > > 
> > > Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> > Do you think that QEMU with TPM 1.2 emulator turned on would be a viable
> > way to test this?
> 
> 
> Yes.

Is the emulator bundled with QEMU or does it have to be installed
separately?

/Jarkko
Jarkko Sakkinen July 7, 2020, 2:24 a.m. UTC | #7 
On Mon, Jul 06, 2020 at 04:57:28PM -0700, Jerry Snitselaar wrote:
> 
> Jarkko Sakkinen @ 2020-07-06 16:09 MST:
> 
> > On Mon, Jul 06, 2020 at 02:19:53PM -0400, Stefan Berger wrote:
> >> From: Stefan Berger <stefanb@linux.ibm.com>
> >> 
> >> In case a TPM2 is attached, search for a TPM2 ACPI table when trying
> >> to get the event log from ACPI. If one is found, use it to get the
> >> start and length of the log area. This allows non-UEFI systems, such
> >> as SeaBIOS, to pass an event log when using a TPM2.
> >> 
> >> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> >
> > Do you think that QEMU with TPM 1.2 emulator turned on would be a viable
> > way to test this?
> >
> > I'm anyway more worried about breaking existing TPM 1.2 functionality
> > and that requires only QEMU without extras.
> >
> > /Jarkko
> 
> The 1.2 bits should be functionally the same as before, right?

Yes. You should be able to read event log with TPM 1.2 as before.

/Jarkko
Stefan Berger July 7, 2020, 3:08 a.m. UTC | #8 
On 7/6/20 10:24 PM, Jarkko Sakkinen wrote:
> On Mon, Jul 06, 2020 at 07:55:26PM -0400, Stefan Berger wrote:
>> On 7/6/20 7:09 PM, Jarkko Sakkinen wrote:
>>> On Mon, Jul 06, 2020 at 02:19:53PM -0400, Stefan Berger wrote:
>>>> From: Stefan Berger <stefanb@linux.ibm.com>
>>>>
>>>> In case a TPM2 is attached, search for a TPM2 ACPI table when trying
>>>> to get the event log from ACPI. If one is found, use it to get the
>>>> start and length of the log area. This allows non-UEFI systems, such
>>>> as SeaBIOS, to pass an event log when using a TPM2.
>>>>
>>>> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
>>> Do you think that QEMU with TPM 1.2 emulator turned on would be a viable
>>> way to test this?
>>
>> Yes.
> Is the emulator bundled with QEMU or does it have to be installed
> separately?

It has to be installed separately. On Fedora 31 it would just be a `sudo 
dnf -y install swtpm-tools` and you should be good to go with libvirt / 
virt-manager.


>
> /Jarkko
Jarkko Sakkinen July 7, 2020, 4:03 a.m. UTC | #9 
On Mon, Jul 06, 2020 at 11:08:12PM -0400, Stefan Berger wrote:
> On 7/6/20 10:24 PM, Jarkko Sakkinen wrote:
> > On Mon, Jul 06, 2020 at 07:55:26PM -0400, Stefan Berger wrote:
> > > On 7/6/20 7:09 PM, Jarkko Sakkinen wrote:
> > > > On Mon, Jul 06, 2020 at 02:19:53PM -0400, Stefan Berger wrote:
> > > > > From: Stefan Berger <stefanb@linux.ibm.com>
> > > > > 
> > > > > In case a TPM2 is attached, search for a TPM2 ACPI table when trying
> > > > > to get the event log from ACPI. If one is found, use it to get the
> > > > > start and length of the log area. This allows non-UEFI systems, such
> > > > > as SeaBIOS, to pass an event log when using a TPM2.
> > > > > 
> > > > > Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> > > > Do you think that QEMU with TPM 1.2 emulator turned on would be a viable
> > > > way to test this?
> > > 
> > > Yes.
> > Is the emulator bundled with QEMU or does it have to be installed
> > separately?
> 
> It has to be installed separately. On Fedora 31 it would just be a `sudo dnf
> -y install swtpm-tools` and you should be good to go with libvirt /
> virt-manager.

Is there some packaging for Debian/Ubuntu available?

/Jarkko
Stefan Berger July 7, 2020, 4:09 a.m. UTC | #10 
On 7/7/20 12:03 AM, Jarkko Sakkinen wrote:
> On Mon, Jul 06, 2020 at 11:08:12PM -0400, Stefan Berger wrote:
>> On 7/6/20 10:24 PM, Jarkko Sakkinen wrote:
>>> On Mon, Jul 06, 2020 at 07:55:26PM -0400, Stefan Berger wrote:
>>>> On 7/6/20 7:09 PM, Jarkko Sakkinen wrote:
>>>>> On Mon, Jul 06, 2020 at 02:19:53PM -0400, Stefan Berger wrote:
>>>>>> From: Stefan Berger <stefanb@linux.ibm.com>
>>>>>>
>>>>>> In case a TPM2 is attached, search for a TPM2 ACPI table when trying
>>>>>> to get the event log from ACPI. If one is found, use it to get the
>>>>>> start and length of the log area. This allows non-UEFI systems, such
>>>>>> as SeaBIOS, to pass an event log when using a TPM2.
>>>>>>
>>>>>> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
>>>>> Do you think that QEMU with TPM 1.2 emulator turned on would be a viable
>>>>> way to test this?
>>>> Yes.
>>> Is the emulator bundled with QEMU or does it have to be installed
>>> separately?
>> It has to be installed separately. On Fedora 31 it would just be a `sudo dnf
>> -y install swtpm-tools` and you should be good to go with libvirt /
>> virt-manager.
> Is there some packaging for Debian/Ubuntu available?


So far may not be available yet. I had *experimented* with a PPA once: 
https://launchpad.net/~stefanberger/+archive/ubuntu/swtpm-focal



> /Jarkko
Jarkko Sakkinen July 8, 2020, 2:07 p.m. UTC | #11 
On Tue, Jul 07, 2020 at 12:09:11AM -0400, Stefan Berger wrote:
> On 7/7/20 12:03 AM, Jarkko Sakkinen wrote:
> > On Mon, Jul 06, 2020 at 11:08:12PM -0400, Stefan Berger wrote:
> > > On 7/6/20 10:24 PM, Jarkko Sakkinen wrote:
> > > > On Mon, Jul 06, 2020 at 07:55:26PM -0400, Stefan Berger wrote:
> > > > > On 7/6/20 7:09 PM, Jarkko Sakkinen wrote:
> > > > > > On Mon, Jul 06, 2020 at 02:19:53PM -0400, Stefan Berger wrote:
> > > > > > > From: Stefan Berger <stefanb@linux.ibm.com>
> > > > > > > 
> > > > > > > In case a TPM2 is attached, search for a TPM2 ACPI table when trying
> > > > > > > to get the event log from ACPI. If one is found, use it to get the
> > > > > > > start and length of the log area. This allows non-UEFI systems, such
> > > > > > > as SeaBIOS, to pass an event log when using a TPM2.
> > > > > > > 
> > > > > > > Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> > > > > > Do you think that QEMU with TPM 1.2 emulator turned on would be a viable
> > > > > > way to test this?
> > > > > Yes.
> > > > Is the emulator bundled with QEMU or does it have to be installed
> > > > separately?
> > > It has to be installed separately. On Fedora 31 it would just be a `sudo dnf
> > > -y install swtpm-tools` and you should be good to go with libvirt /
> > > virt-manager.
> > Is there some packaging for Debian/Ubuntu available?
> 
> 
> So far may not be available yet. I had *experimented* with a PPA once:
> https://launchpad.net/~stefanberger/+archive/ubuntu/swtpm-focal

There is a snap available:

name:      swtpm-mvo
summary:   Libtpms-based TPM emulator
publisher: Michael Vogt (mvo)
store-url: https://snapcraft.io/swtpm-mvo
license:   unset
description: |
  Libtpms-based TPM emulator with socket, character device, and Linux
  CUSE interface.
commands:
  - swtpm-mvo.swtpm
services:
  swtpm-mvo.swtpm-sock: simple, enabled, active
snap-id:      HNl1TwHRBk3OtXQ8OriRB93FDZ6vman7
tracking:     latest/edge
refresh-date: today at 02:05 EEST
channels:
  latest/stable:    –                         
  latest/candidate: –                         
  latest/beta:      0.1.0 2019-07-26 (11) 3MB -
  latest/edge:      0.1.0 2020-07-08 (75) 3MB -
installed:          0.1.0            (74) 3MB -

This is the version information:

❯ swtpm-mvo.swtpm --version
TPM emulator version 0.4.0, Copyright (c) 2014 IBM Corp.

However, if I try to run the first example from [*], I get:

❯ swtpm-mvo.swtpm socket --tpmstate dir=/tmp/mytpm1 \
  --ctrl type=unixio,path=/tmp/mytpm1/swtpm-sock \
  --log level=20
swtpm: Could not open UnixIO socket: No such file or directory

[*] https://www.qemu.org/docs/master/specs/tpm.html

/Jarkko
Stefan Berger July 8, 2020, 2:17 p.m. UTC | #12 
On 7/8/20 10:07 AM, Jarkko Sakkinen wrote:
> On Tue, Jul 07, 2020 at 12:09:11AM -0400, Stefan Berger wrote:
>> On 7/7/20 12:03 AM, Jarkko Sakkinen wrote:
>>> On Mon, Jul 06, 2020 at 11:08:12PM -0400, Stefan Berger wrote:
>>>> On 7/6/20 10:24 PM, Jarkko Sakkinen wrote:
>>>>> On Mon, Jul 06, 2020 at 07:55:26PM -0400, Stefan Berger wrote:
>>>>>> On 7/6/20 7:09 PM, Jarkko Sakkinen wrote:
>>>>>>> On Mon, Jul 06, 2020 at 02:19:53PM -0400, Stefan Berger wrote:
>>>>>>>> From: Stefan Berger <stefanb@linux.ibm.com>
>>>>>>>>
>>>>>>>> In case a TPM2 is attached, search for a TPM2 ACPI table when trying
>>>>>>>> to get the event log from ACPI. If one is found, use it to get the
>>>>>>>> start and length of the log area. This allows non-UEFI systems, such
>>>>>>>> as SeaBIOS, to pass an event log when using a TPM2.
>>>>>>>>
>>>>>>>> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
>>>>>>> Do you think that QEMU with TPM 1.2 emulator turned on would be a viable
>>>>>>> way to test this?
>>>>>> Yes.
>>>>> Is the emulator bundled with QEMU or does it have to be installed
>>>>> separately?
>>>> It has to be installed separately. On Fedora 31 it would just be a `sudo dnf
>>>> -y install swtpm-tools` and you should be good to go with libvirt /
>>>> virt-manager.
>>> Is there some packaging for Debian/Ubuntu available?
>>
>> So far may not be available yet. I had *experimented* with a PPA once:
>> https://launchpad.net/~stefanberger/+archive/ubuntu/swtpm-focal
> There is a snap available:
>
> name:      swtpm-mvo
> summary:   Libtpms-based TPM emulator
> publisher: Michael Vogt (mvo)
> store-url: https://snapcraft.io/swtpm-mvo
> license:   unset
> description: |
>    Libtpms-based TPM emulator with socket, character device, and Linux
>    CUSE interface.
> commands:
>    - swtpm-mvo.swtpm
> services:
>    swtpm-mvo.swtpm-sock: simple, enabled, active
> snap-id:      HNl1TwHRBk3OtXQ8OriRB93FDZ6vman7
> tracking:     latest/edge
> refresh-date: today at 02:05 EEST
> channels:
>    latest/stable:    –
>    latest/candidate: –
>    latest/beta:      0.1.0 2019-07-26 (11) 3MB -
>    latest/edge:      0.1.0 2020-07-08 (75) 3MB -
> installed:          0.1.0            (74) 3MB -
>
> This is the version information:
>
> ❯ swtpm-mvo.swtpm --version
> TPM emulator version 0.4.0, Copyright (c) 2014 IBM Corp.
>
> However, if I try to run the first example from [*], I get:
>
> ❯ swtpm-mvo.swtpm socket --tpmstate dir=/tmp/mytpm1 \
>    --ctrl type=unixio,path=/tmp/mytpm1/swtpm-sock \
>    --log level=20
> swtpm: Could not open UnixIO socket: No such file or directory


Did you create the directory '/tmp/mytpm1' ?


> [*] https://www.qemu.org/docs/master/specs/tpm.html
>
> /Jarkko
Jarkko Sakkinen July 14, 2020, 11:20 a.m. UTC | #13 
On Wed, Jul 08, 2020 at 10:17:17AM -0400, Stefan Berger wrote:
> > ❯ swtpm-mvo.swtpm socket --tpmstate dir=/tmp/mytpm1 \
> >    --ctrl type=unixio,path=/tmp/mytpm1/swtpm-sock \
> >    --log level=20
> > swtpm: Could not open UnixIO socket: No such file or directory
> 
> 
> Did you create the directory '/tmp/mytpm1' ?

Yes. It's the socket file that it is complain because it does
not exist beforehand.

/Jarkko
Stefan Berger July 14, 2020, 12:09 p.m. UTC | #14 
On 7/14/20 7:20 AM, Jarkko Sakkinen wrote:
> On Wed, Jul 08, 2020 at 10:17:17AM -0400, Stefan Berger wrote:
>>> ❯ swtpm-mvo.swtpm socket --tpmstate dir=/tmp/mytpm1 \
>>>     --ctrl type=unixio,path=/tmp/mytpm1/swtpm-sock \
>>>     --log level=20
>>> swtpm: Could not open UnixIO socket: No such file or directory
>>
>> Did you create the directory '/tmp/mytpm1' ?
> Yes. It's the socket file that it is complain because it does
> not exist beforehand.


The socket file is created by the swtpm program.


>
> /Jarkko
Jarkko Sakkinen July 16, 2020, 5:26 p.m. UTC | #15 
On Tue, Jul 14, 2020 at 08:09:03AM -0400, Stefan Berger wrote:
> On 7/14/20 7:20 AM, Jarkko Sakkinen wrote:
> > On Wed, Jul 08, 2020 at 10:17:17AM -0400, Stefan Berger wrote:
> > > > ❯ swtpm-mvo.swtpm socket --tpmstate dir=/tmp/mytpm1 \
> > > >     --ctrl type=unixio,path=/tmp/mytpm1/swtpm-sock \
> > > >     --log level=20
> > > > swtpm: Could not open UnixIO socket: No such file or directory
> > > 
> > > Did you create the directory '/tmp/mytpm1' ?
> > Yes. It's the socket file that it is complain because it does
> > not exist beforehand.
> 
> 
> The socket file is created by the swtpm program.

I got this tested with real hardware, i.e. tested that TPM 1.2 works.

Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

/Jarkko
diff mbox series

Patch

diff --git a/drivers/char/tpm/eventlog/acpi.c b/drivers/char/tpm/eventlog/acpi.c
index 63ada5e53f13..3633ed70f48f 100644
--- a/drivers/char/tpm/eventlog/acpi.c
+++ b/drivers/char/tpm/eventlog/acpi.c
@@ -49,9 +49,9 @@  int tpm_read_log_acpi(struct tpm_chip *chip)
 	void __iomem *virt;
 	u64 len, start;
 	struct tpm_bios_log *log;
-
-	if (chip->flags & TPM_CHIP_FLAG_TPM2)
-		return -ENODEV;
+	struct acpi_table_tpm2 *tbl;
+	struct acpi_tpm2_phy *tpm2_phy;
+	int format;
 
 	log = &chip->log;
 
@@ -61,23 +61,44 @@  int tpm_read_log_acpi(struct tpm_chip *chip)
 	if (!chip->acpi_dev_handle)
 		return -ENODEV;
 
-	/* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
-	status = acpi_get_table(ACPI_SIG_TCPA, 1,
-				(struct acpi_table_header **)&buff);
-
-	if (ACPI_FAILURE(status))
-		return -ENODEV;
-
-	switch(buff->platform_class) {
-	case BIOS_SERVER:
-		len = buff->server.log_max_len;
-		start = buff->server.log_start_addr;
-		break;
-	case BIOS_CLIENT:
-	default:
-		len = buff->client.log_max_len;
-		start = buff->client.log_start_addr;
-		break;
+	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
+		status = acpi_get_table("TPM2", 1,
+					(struct acpi_table_header **)&tbl);
+		if (ACPI_FAILURE(status))
+			return -ENODEV;
+
+		if (tbl->header.length <
+				sizeof(*tbl) + sizeof(struct acpi_tpm2_phy))
+			return -ENODEV;
+
+		tpm2_phy = (void *)tbl + sizeof(*tbl);
+		len = tpm2_phy->log_area_minimum_length;
+
+		start = tpm2_phy->log_area_start_address;
+		if (!start || !len)
+			return -ENODEV;
+
+		format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
+	} else {
+		/* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
+		status = acpi_get_table(ACPI_SIG_TCPA, 1,
+					(struct acpi_table_header **)&buff);
+		if (ACPI_FAILURE(status))
+			return -ENODEV;
+
+		switch (buff->platform_class) {
+		case BIOS_SERVER:
+			len = buff->server.log_max_len;
+			start = buff->server.log_start_addr;
+			break;
+		case BIOS_CLIENT:
+		default:
+			len = buff->client.log_max_len;
+			start = buff->client.log_start_addr;
+			break;
+		}
+
+		format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
 	}
 	if (!len) {
 		dev_warn(&chip->dev, "%s: TCPA log area empty\n", __func__);
@@ -98,7 +119,7 @@  int tpm_read_log_acpi(struct tpm_chip *chip)
 	memcpy_fromio(log->bios_event_log, virt, len);
 
 	acpi_os_unmap_iomem(virt, len);
-	return EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
+	return format;
 
 err:
 	kfree(log->bios_event_log);