45a70db3c3
These settings will allow CpuMpPei and CpuDxe to wait for the initial AP
check-ins exactly as long as necessary.
It is safe to set PcdCpuMaxLogicalProcessorNumber and
PcdCpuApInitTimeOutInMicroSeconds in OvmfPkg/PlatformPei.
OvmfPkg/PlatformPei installs the permanent PEI RAM, producing
gEfiPeiMemoryDiscoveredPpiGuid, and UefiCpuPkg/CpuMpPei has a depex on
gEfiPeiMemoryDiscoveredPpiGuid.
It is safe to read the fw_cfg item QemuFwCfgItemSmpCpuCount (0x0005). It
was added to QEMU in 2008 as key FW_CFG_NB_CPUS, in commit 905fdcb5264c
("Add common keys to firmware configuration"). Even if the key is
unavailable (or if fw_cfg is entirely unavailable, for example on Xen),
QemuFwCfgRead16() will return 0, and then we stick with the current
behavior.
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jeff Fan <jeff.fan@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>