[PATCH 1/3] x86/spec-ctrl: Split the "Hardware features" diagnostic line

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

Separate the read-only hints from the features requiring active actions on
Xen's behalf.

Also take the opportunity split the IBRS/IBPB and IBPB mess.  More features
with overlapping enumeration are on the way, and and it is not useful to split
them like this.

No practical change.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
---
 xen/arch/x86/spec_ctrl.c | 41 ++++++++++++++++++++++++-----------------
 1 file changed, 24 insertions(+), 17 deletions(-)

diff --git a/xen/arch/x86/spec_ctrl.c b/xen/arch/x86/spec_ctrl.c
index 739b7913ff86..9bf0fbf99813 100644
--- a/xen/arch/x86/spec_ctrl.c
+++ b/xen/arch/x86/spec_ctrl.c
@@ -317,23 +317,30 @@ static void __init print_details(enum ind_thunk thunk, 
uint64_t caps)
 
     printk("Speculative mitigation facilities:\n");
 
-    /* Hardware features which pertain to speculative mitigations. */
-    printk("  Hardware features:%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n",
-           (_7d0 & cpufeat_mask(X86_FEATURE_IBRSB)) ? " IBRS/IBPB" : "",
-           (_7d0 & cpufeat_mask(X86_FEATURE_STIBP)) ? " STIBP"     : "",
-           (_7d0 & cpufeat_mask(X86_FEATURE_L1D_FLUSH)) ? " L1D_FLUSH" : "",
-           (_7d0 & cpufeat_mask(X86_FEATURE_SSBD))  ? " SSBD"      : "",
-           (_7d0 & cpufeat_mask(X86_FEATURE_MD_CLEAR)) ? " MD_CLEAR" : "",
-           (_7d0 & cpufeat_mask(X86_FEATURE_SRBDS_CTRL)) ? " SRBDS_CTRL" : "",
-           (e8b  & cpufeat_mask(X86_FEATURE_IBPB))  ? " IBPB"      : "",
-           (caps & ARCH_CAPS_IBRS_ALL)              ? " IBRS_ALL"  : "",
-           (caps & ARCH_CAPS_RDCL_NO)               ? " RDCL_NO"   : "",
-           (caps & ARCH_CAPS_RSBA)                  ? " RSBA"      : "",
-           (caps & ARCH_CAPS_SKIP_L1DFL)            ? " SKIP_L1DFL": "",
-           (caps & ARCH_CAPS_SSB_NO)                ? " SSB_NO"    : "",
-           (caps & ARCH_CAPS_MDS_NO)                ? " MDS_NO"    : "",
-           (caps & ARCH_CAPS_TSX_CTRL)              ? " TSX_CTRL"  : "",
-           (caps & ARCH_CAPS_TAA_NO)                ? " TAA_NO"    : "");
+    /*
+     * Hardware read-only information, stating immunity to certain issues, or
+     * suggestions of which mitigation to use.
+     */
+    printk("  Hardware hints:%s%s%s%s%s%s%s\n",
+           (caps & ARCH_CAPS_RDCL_NO)                        ? " RDCL_NO"      
  : "",
+           (caps & ARCH_CAPS_IBRS_ALL)                       ? " IBRS_ALL"     
  : "",
+           (caps & ARCH_CAPS_RSBA)                           ? " RSBA"         
  : "",
+           (caps & ARCH_CAPS_SKIP_L1DFL)                     ? " SKIP_L1DFL"   
  : "",
+           (caps & ARCH_CAPS_SSB_NO)                         ? " SSB_NO"       
  : "",
+           (caps & ARCH_CAPS_MDS_NO)                         ? " MDS_NO"       
  : "",
+           (caps & ARCH_CAPS_TAA_NO)                         ? " TAA_NO"       
  : "");
+
+    /* Hardware features which need driving to mitigate issues. */
+    printk("  Hardware features:%s%s%s%s%s%s%s%s\n",
+           (e8b  & cpufeat_mask(X86_FEATURE_IBPB)) ||
+           (_7d0 & cpufeat_mask(X86_FEATURE_IBRSB))          ? " IBPB"         
  : "",
+           (_7d0 & cpufeat_mask(X86_FEATURE_IBRSB))          ? " IBRS"         
  : "",
+           (_7d0 & cpufeat_mask(X86_FEATURE_STIBP))          ? " STIBP"        
  : "",
+           (_7d0 & cpufeat_mask(X86_FEATURE_SSBD))           ? " SSBD"         
  : "",
+           (_7d0 & cpufeat_mask(X86_FEATURE_L1D_FLUSH))      ? " L1D_FLUSH"    
  : "",
+           (_7d0 & cpufeat_mask(X86_FEATURE_MD_CLEAR))       ? " MD_CLEAR"     
  : "",
+           (_7d0 & cpufeat_mask(X86_FEATURE_SRBDS_CTRL))     ? " SRBDS_CTRL"   
  : "",
+           (caps & ARCH_CAPS_TSX_CTRL)                       ? " TSX_CTRL"     
  : "");
 
     /* Compiled-in support which pertains to mitigations. */
     if ( IS_ENABLED(CONFIG_INDIRECT_THUNK) || IS_ENABLED(CONFIG_SHADOW_PAGING) 
)
-- 
2.11.0