On 08.08.2025 22:23, Andrew Cooper wrote: > --- a/xen/arch/x86/acpi/wakeup_prot.S > +++ b/xen/arch/x86/acpi/wakeup_prot.S > @@ -63,6 +63,9 @@ LABEL(s3_resume) > pushq %rax > lretq > 1: > + /* Set up early exceptions and CET before entering C properly. */ > + call ap_early_traps_init
But this is the BSP? > --- a/xen/arch/x86/smpboot.c > +++ b/xen/arch/x86/smpboot.c > @@ -327,12 +327,7 @@ void asmlinkage start_secondary(void) > struct cpu_info *info = get_cpu_info(); > unsigned int cpu = smp_processor_id(); > > - /* Critical region without IDT or TSS. Any fault is deadly! */ > - > - set_current(idle_vcpu[cpu]); > - this_cpu(curr_vcpu) = idle_vcpu[cpu]; > rdmsrl(MSR_EFER, this_cpu(efer)); > - init_shadow_spec_ctrl_state(info); > > /* > * Just as during early bootstrap, it is convenient here to disable > @@ -352,14 +347,6 @@ void asmlinkage start_secondary(void) > */ > spin_debug_disable(); > > - get_cpu_info()->use_pv_cr3 = false; > - get_cpu_info()->xen_cr3 = 0; > - get_cpu_info()->pv_cr3 = 0; > - > - load_system_tables(); > - > - /* Full exception support from here on in. */ > - > if ( cpu_has_pks ) > wrpkrs_and_cache(0); /* Must be before setting CR4.PKS */ > > @@ -1064,8 +1051,12 @@ static int cpu_smpboot_alloc(unsigned int cpu) > goto out; > > info = get_cpu_info_from_stack((unsigned long)stack_base[cpu]); > + memset(info, 0, sizeof(*info)); Why do we suddenly need this? Or is this just out of an abundance of caution (while making the individual ->*_cr3 writes unnecessary)? > + init_shadow_spec_ctrl_state(info); May I suggest to move this further down a little, at least ... > info->processor_id = cpu; ... past here? Just in case other values in the struct may be needed in the function at some point. > info->per_cpu_offset = __per_cpu_offset[cpu]; > + info->current_vcpu = idle_vcpu[cpu]; To be able to spot this, I think it wants /* set_current() */ or some such. > + per_cpu(curr_vcpu, cpu) = idle_vcpu[cpu]; It's a little odd to do this early (and remotely), but it looks all fine with how the variable is currently used. Jan
