[PATCH 0/1] OvmfPkg/PlatformInitLib: catch QEMU's CPU hotplug reg block regression

["Laszlo Ersek" <lersek@redhat.com>]

Repo:       https://pagure.io/lersek/edk2.git
Branch:     cpuhp-reg-catch-4250
Test build: https://github.com/tianocore/edk2/pull/3853
Bugzilla:   https://bugzilla.tianocore.org/show_bug.cgi?id=4250

NOTE: the test build linked above (in the github.com CI env) *failed*.
That's because the CI environment is affected by this very QEMU bug!

Namely, the following checks failed -- due to the intentional hang
introduced in this patch:

- PlatformCI_OvmfPkg_Ubuntu_GCC5_PR (12 tests)
- PlatformCI_OvmfPkg_Windows_VS2019_PR (11 tests)

(The Build_VS2019_TARGET_CODE_COVERAGE and
Build_GCC5_TARGET_CODE_COVERAGE tests also failed, but those seem bogus
to me.)

All 12+11=23 PlatformCI_OvmfPkg_* checks failed due to timeout, and the
firmware logs of the DEBUG and NOOPT builds end with:

> INFO - PlatformMaxCpuCountInitialization: Broken CPU hotplug register block: Present=0 Possible=1.
> INFO - PlatformMaxCpuCountInitialization: Switch QEMU's acceleration from TCG to KVM, or update QEMU.
> INFO - PlatformMaxCpuCountInitialization: Refer to <https://bugzilla.tianocore.org/show_bug.cgi?id=4250>.
> INFO - ASSERT /home/vsts/work/1/s/OvmfPkg/Library/PlatformInitLib/Platform.c(574): ((BOOLEAN)(0==1))

So I'm not proposing to merge this immediately; something must be fixed
first:

- use KVM in the CI env, or

- delay this patch until my QEMU fix is merged, and a new release is
  made, and the new QEMU release is packaged by the distros, and the new
  distro packages are picked up by github.com CI.

Suggestions?

Thanks,
Laszlo

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Min Xu <min.m.xu@intel.com>
Cc: Sebastien Boeuf <sebastien.boeuf@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>

Laszlo Ersek (1):
  OvmfPkg/PlatformInitLib: catch QEMU's CPU hotplug reg block regression

 OvmfPkg/Library/PlatformInitLib/Platform.c | 34 ++++++++++++++++++++
 1 file changed, 34 insertions(+)