On 10/22/2012 01:33 PM, H. Peter Anvin wrote: > On 10/22/2012 01:31 PM, Eric W. Biederman wrote: >>> >>> IIRC Fenghua experimented with that and it didn't work. Not all BIOSes >>> use that bit to determine BSP-ness. >> >> What does a BIOS have to do with anything? >> >> The practical issue here is does an INIT IPI cause the cpu to go into >> startup-ipi-wait or to start booting at 4G-16 bytes. >> >> For dealing with BIOSen we may still need to use the bootstrap processor >> for firmware calls, cpu suspend, and other firmware weirdness, but that >> should all be completely orthogonal to the behavior to what happens >> when an INIT IPI is sent to the cpu. >> >> The only firmware problem I can imagine having is cpu virtualization >> bug. >> > > The whole problem is that some BIOSes go wonky after receiving an INIT > (as in INIT-SIPI-SIPI) to the BSP. > (I presume the failure is SMM-related, but Fenghua might have more details...) -hpa