Re: Enabling TPM support in ovmf & hang during qemu boot

["Yao, Jiewen" <jiewen.yao@intel.com>]

I can not add memorydiscovered dependency for tcgpei. We do have use case to unit Tpm before memory.

By design, tcgconfig peim is a platform module. Ovmf can create its own one and add dependency there.

As such, tcgpei depends on tcgconfigpei, and later can depend on memory.

thank you!
Yao, Jiewen


> 在 2017年11月13日，下午7:26，Laszlo Ersek <lersek@redhat.com> 写道：
> 
>> On 11/12/17 20:09, Marc-André Lureau wrote:
>> Hi,
>> 
>> I use the attached patch to build OVMF with TPM support.
>> 
>> Even without any TPM device configured (with the following qemu
>> command line) the VM hangs early:
>> 
>> qemu-system-x86_64 -enable-kvm -m 1024 -global
>> isa-debugcon.iobase=0x402 -debugcon file:ovmf.log -drive
>> if=pflash,format=raw,file=...src/edk2/Build/OvmfX64/DEBUG_GCC5/FV/OVMF_CODE.fd,readonly
>> -drive if=pflash,format=raw,file=...src/edk2/Build/OvmfX64/DEBUG_GCC5/FV/OVMF_VARS.fd
>> 
>> I don't have much clue how to debug OVMF, but adding DEBUG lines, I
>> could learn that during ReserveEmuVariableNvStore(), GetNextHob() runs
>> an infinite loop, looking for EFI_HOB_TYPE_UNUSED.
>> 
>> How is the HobList populated? Is it possible to add more of the UNUSED entries?
>> 
>> Any help welcome
>> 
> 
> * Neither Tcg2ConfigPei nor Tcg2Pei depend, in their INF files' [depex]
> section, on "permanent RAM has been discovered" (=
> gEfiPeiMemoryDiscoveredPpiGuid). This means that they can be dispatched
> before OvmfPkg/PlatformPei installs the permanent PEI RAM. Therefore, if
> they call PeiServicesAllocatePages(), the allocation likely runs out of
> the -- very small -- termporary PEI RAM that we have in OVMF.
> 
> The way to mitigate this is either to increase the temp PEI RAM (I
> already have such a set on the list, but for different purposes -- and
> this approach only works if the needed memory is really small), or to
> make both of these PEIMs dependent on gEfiPeiMemoryDiscoveredPpiGuid. I
> can't say -- Jiewen, would it be OK to make these PEIMs dependent on
> gEfiPeiMemoryDiscoveredPpiGuid?
> 
> 
> * Both PEIMs depend on PEI-phase read-only variable access
> (gEfiPeiReadOnlyVariable2PpiGuid). However, OVMF does not include the
> required drivers at the moment -- see
> <https://bugzilla.tianocore.org/show_bug.cgi?id=386>. I had posted a
> series for that back in ~March 2017, but Jordan disagreed with them. (I
> think each of us remains unconvinced by the other's points, from the
> original thread.)
> 
> Thanks
> Laszlo