On 2/13/23 13:13, Huang, Kai wrote: > Perhaps I didn't explain clearly in the comment. Below is the updated one: > > /* > * The previous call of __tdx_enable() may only have > * initialized part of present cpus during module > * initialization, and new cpus may have become online > * since then w/o doing per-cpu initialization. > * > * For example, a new CPU can become online when KVM is > * unloaded, in which case tdx_cpu_enable() is not called since > * KVM's CPU online callback has been removed. > * > * To make sure all online cpus are TDX-runnable, always > * do per-cpu initialization for all online cpus here > * even the module has been initialized. > */ This is voodoo. I want a TDX-specific hotplug CPU handler. Period. Please make that happen. Put that code in this patch. That handler should: 1. Run after the KVM handler (if present) 2. See if VMX is on 3. If VMX is on: 3a. Run smp_func_module_lp_init(), else 3b. Mark the CPU as needing smp_func_module_lp_init() Then, in the 'case TDX_MODULE_INITIALIZED:', you call a function to iterate over the cpumask that was generated in 3b. That makes the handoff *EXPLICIT*. You know exactly which CPUs need what done to them. A CPU hotplug either explicitly involves doing the work to make TDX work on the CPU, or explicitly defers the work to a specific later time in a specific later piece of code.
