Re: [edk2-devel] [PATCH v2 3/4] OvmfPkg: Define a new PPI GUID to signal TPM MMIO accessability

["Lendacky, Thomas" <thomas.lendacky@amd.com>]

On 4/28/21 12:15 PM, Laszlo Ersek wrote:
> On 04/28/21 19:12, Laszlo Ersek wrote:
>> On 04/27/21 18:21, Lendacky, Thomas wrote:
>>> From: Tom Lendacky <thomas.lendacky@amd.com>
>>>
>>> Define a new PPI GUID that is to be used as a signal of when it is safe
>>> to access the TPM MMIO range. This is needed so that, when SEV is active,
>>> the MMIO range can be mapped unencrypted before it is accessed.
>>>
>>> Cc: Laszlo Ersek <lersek@redhat.com>
>>> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
>>> Cc: Jordan Justen <jordan.l.justen@intel.com>
>>> Cc: Brijesh Singh <brijesh.singh@amd.com>
>>> Cc: Erdem Aktas <erdemaktas@google.com>
>>> Cc: James Bottomley <jejb@linux.ibm.com>
>>> Cc: Jiewen Yao <jiewen.yao@intel.com>
>>> Cc: Min Xu <min.m.xu@intel.com>
>>> Cc: Marc-Andr?? Lureau <marcandre.lureau@redhat.com>
> 
> (1) Marc-André's name is garbled here, but I can fix it up.

Sorry about that, looks like my email system didn't like the accent
symbol. I'll look into that and see if I can't fix it (it could also be my
.gitconfig).

Thanks,
Tom

> 
> Thanks
> Laszlo
> 
>>> Cc: Stefan Berger <stefanb@linux.ibm.com>
>>> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
>>> ---
>>>  OvmfPkg/OvmfPkg.dec | 4 ++++
>>>  1 file changed, 4 insertions(+)
>>>
>>> diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec
>>> index 9629707020ba..6ae733f6e39f 100644
>>> --- a/OvmfPkg/OvmfPkg.dec
>>> +++ b/OvmfPkg/OvmfPkg.dec
>>> @@ -128,6 +128,10 @@ [Ppis]
>>>    # has been discovered and recorded
>>>    gOvmfTpmDiscoveredPpiGuid             = {0xb9a61ad0, 0x2802, 0x41f3, {0xb5, 0x13, 0x96, 0x51, 0xce, 0x6b, 0xd5, 0x75}}
>>>  
>>> +  # This PPI signals that accessing the MMIO range of the TPM is possible in
>>> +  # the PEI phase, regardless of memory encryption
>>> +  gOvmfTpmMmioAccessiblePpiGuid         = {0x35c84ff2, 0x7bfe, 0x453d, {0x84, 0x5f, 0x68, 0x3a, 0x49, 0x2c, 0xf7, 0xb7}}
>>> +
>>>  [Protocols]
>>>    gVirtioDeviceProtocolGuid             = {0xfa920010, 0x6785, 0x4941, {0xb6, 0xec, 0x49, 0x8c, 0x57, 0x9f, 0x16, 0x0a}}
>>>    gXenBusProtocolGuid                   = {0x3d3ca290, 0xb9a5, 0x11e3, {0xb7, 0x5d, 0xb8, 0xac, 0x6f, 0x7d, 0x65, 0xe6}}
>>>
>>
>> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
>>
>