x86/spec-ctrl: Rework init_shadow_spec_ctrl_state() to take an info pointer

We're going to want to reuse it for a remote stack shortly.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

xen/arch/x86/include/asm/spec_ctrl.h

@@ -99,10 +99,8 @@ extern bool opt_bp_spec_reduce;
  */
 extern paddr_t l1tf_addr_mask, l1tf_safe_maddr;
 
-static inline void init_shadow_spec_ctrl_state(void)
+static inline void init_shadow_spec_ctrl_state(struct cpu_info *info)
 {
-    struct cpu_info *info = get_cpu_info();
-
     info->shadow_spec_ctrl = 0;
     info->xen_spec_ctrl = default_xen_spec_ctrl;
     info->scf = default_scf;

xen/arch/x86/setup.c

@@ -1126,7 +1126,7 @@ void asmlinkage __init noreturn __start_xen(void)
 
     /* Critical region without exception handling.  Any fault is deadly! */
 
-    init_shadow_spec_ctrl_state();
+    init_shadow_spec_ctrl_state(info);
 
     percpu_init_areas();
 

xen/arch/x86/smpboot.c

@@ -332,7 +332,7 @@ void asmlinkage start_secondary(void)
     set_current(idle_vcpu[cpu]);
     this_cpu(curr_vcpu) = idle_vcpu[cpu];
     rdmsrl(MSR_EFER, this_cpu(efer));
-    init_shadow_spec_ctrl_state();
+    init_shadow_spec_ctrl_state(info);
 
     /*
      * Just as during early bootstrap, it is convenient here to disable

xen/arch/x86/spec_ctrl.c

@@ -2226,7 +2226,7 @@ void __init init_speculation_mitigations(void)
         opt_eager_fpu = should_use_eager_fpu();
 
     /* (Re)init BSP state now that default_scf has been calculated. */
-    init_shadow_spec_ctrl_state();
+    init_shadow_spec_ctrl_state(get_cpu_info());
 
     /*
      * For microcoded IBRS only (i.e. Intel, pre eIBRS), it is recommended to