commit 03de6917bd11c0591867607ce74ef658f76eabb9
Author: Aurelien Jarno <aurelien@aurel32.net>
Date:   Wed Dec 15 23:46:19 2021 +0100
 
    elf: Fix tst-cpu-features-cpuinfo for KVM guests on some AMD systems [BZ #28704]
    
    On KVM guests running on some AMD systems, the IBRS feature is reported
    as a synthetic feature using the Intel feature, while the cpuinfo entry
    keeps the same. Handle that by first checking the presence of the Intel
    feature on AMD systems.
    
    Fixes bug 28704.
    
    (cherry picked from commit 94058f6cde8b887178885954740ac6c866d25eab)
 
diff --git a/sysdeps/x86/tst-cpu-features-cpuinfo.c b/sysdeps/x86/tst-cpu-features-cpuinfo.c
index 2d4927f5e52dc260..830aaca2ecae971b 100644
--- a/sysdeps/x86/tst-cpu-features-cpuinfo.c
+++ b/sysdeps/x86/tst-cpu-features-cpuinfo.c
@@ -169,7 +169,14 @@ do_test (int argc, char **argv)
   else if (cpu_features->basic.kind == arch_kind_amd)
     {
       fails += CHECK_PROC (ibpb, AMD_IBPB);
-      fails += CHECK_PROC (ibrs, AMD_IBRS);
+
+      /* The IBRS feature on AMD processors is reported using the Intel feature
+       * on KVM guests (synthetic bit).  In both cases the cpuinfo entry is the
+       * same.  */
+      if (HAS_CPU_FEATURE (IBRS_IBPB))
+        fails += CHECK_PROC (ibrs, IBRS_IBPB);
+      else
+        fails += CHECK_PROC (ibrs, AMD_IBRS);
       fails += CHECK_PROC (stibp, AMD_STIBP);
     }
   fails += CHECK_PROC (ibt, IBT);