File xsa471-08.patch of Package xen.39650

# Commit 30f8fed68f3c2e63594ff9202b3d05b971781e36
# Date 2025-06-30 12:41:33 +0100
# Author Andrew Cooper <andrew.cooper3@citrix.com>
# Committer Andrew Cooper <andrew.cooper3@citrix.com>
x86/cpu-policy: Simplify logic in guest_common_default_feature_adjustments()

For features which are unconditionally set in the max policies, making the
default policy to match the host can be done with a conditional clear.

This is simpler than the unconditional clear, conditional set currently
performed.

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

--- a/xen/arch/x86/cpu-policy.c
+++ b/xen/arch/x86/cpu-policy.c
@@ -500,17 +500,14 @@ static void __init guest_common_default_
          * reasons, so reset the default policy back to the host values in
          * case we're unaffected.
          */
-        __clear_bit(X86_FEATURE_MD_CLEAR, fs);
-        if ( cpu_has_md_clear )
-            __set_bit(X86_FEATURE_MD_CLEAR, fs);
+        if ( !cpu_has_md_clear )
+            __clear_bit(X86_FEATURE_MD_CLEAR, fs);
 
-        __clear_bit(X86_FEATURE_FB_CLEAR, fs);
-        if ( cpu_has_fb_clear )
-            __set_bit(X86_FEATURE_FB_CLEAR, fs);
+        if ( !cpu_has_fb_clear )
+            __clear_bit(X86_FEATURE_FB_CLEAR, fs);
 
-        __clear_bit(X86_FEATURE_RFDS_CLEAR, fs);
-        if ( cpu_has_rfds_clear )
-            __set_bit(X86_FEATURE_RFDS_CLEAR, fs);
+        if ( !cpu_has_rfds_clear )
+            __clear_bit(X86_FEATURE_RFDS_CLEAR, fs);
 
         /*
          * The Gather Data Sampling microcode mitigation (August 2023) has an