On Thu, May 04, 2023 at 02:50:18PM +0000, Ross Philipson wrote:
> On Intel, the APs are left in a well documented state after TXT performs
> the late launch. Specifically they cannot have #INIT asserted on them so
> a standard startup via INIT/SIPI/SIPI cannot be performed. Instead the
> early SL stub code parked the APs in a pause/jmp loop waiting for an NMI.
> The modified SMP boot code is called for the Secure Launch case. The
> jump address for the RM piggy entry point is fixed up in the jump where
> the APs are waiting and an NMI IPI is sent to the AP. The AP vectors to
> the Secure Launch entry point in the RM piggy which mimics what the real
> mode code would do then jumps to the standard RM piggy protected mode
> entry point.
>
> Signed-off-by: Ross Philipson <ross.philipson@xxxxxxxxxx>
Hi Ross,
just one minor nit on this one.
> /*
> * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
> * (ie clustered apic addressing mode), this is a LOGICAL apic ID.
> @@ -1132,6 +1210,13 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle,
> cpumask_clear_cpu(cpu, cpu_initialized_mask);
> smp_mb();
>
> + /* With Intel TXT, the AP startup is totally different */
> + if ((slaunch_get_flags() & (SL_FLAG_ACTIVE|SL_FLAG_ARCH_TXT)) ==
nit: spaces around '|'
> + (SL_FLAG_ACTIVE|SL_FLAG_ARCH_TXT)) {
> + boot_error = slaunch_wakeup_cpu_from_txt(cpu, apicid);
> + goto txt_wake;
> + }
