[xen master] x86: calculate number of synthetic feature and bug enumerators

[patchbot@xxxxxxx]

commit 191e2c7a02b0f6454ad9bf8876192b00df3adf6a
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Tue Feb 3 15:11:53 2026 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Feb 3 15:11:53 2026 +0100

    x86: calculate number of synthetic feature and bug enumerators
    
    Rather than spelling out their amounts (requiring updates when multiples
    of 32 are crossed), introduce a sentinel each and calculate the two
    numbers from those.
    
    No difference in generated code, albeit debug info size grows quite a bit.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/include/asm/cpufeatures.h | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/include/asm/cpufeatures.h 
b/xen/arch/x86/include/asm/cpufeatures.h
index 0d90924e3e..f7958110af 100644
--- a/xen/arch/x86/include/asm/cpufeatures.h
+++ b/xen/arch/x86/include/asm/cpufeatures.h
@@ -7,7 +7,6 @@
 #define FSCAPINTS FEATURESET_NR_ENTRIES
 
 /* Synthetic words follow the featureset words. */
-#define X86_NR_SYNTH 2
 #define X86_SYNTH(x) (FSCAPINTS * 32 + (x))
 
 /* Synthetic features */
@@ -44,9 +43,11 @@ XEN_CPUFEATURE(IBPB_ENTRY_HVM,    X86_SYNTH(29)) /* 
MSR_PRED_CMD used by Xen for
 XEN_CPUFEATURE(USE_VMCALL,        X86_SYNTH(30)) /* Use VMCALL instead of 
VMMCALL */
 XEN_CPUFEATURE(PDX_COMPRESSION,   X86_SYNTH(31)) /* PDX compression */
 XEN_CPUFEATURE(XEN_REP_MOVSB,     X86_SYNTH(32)) /* REP MOVSB used for 
memcpy() */
+XEN_CPUFEATURE(nr,                X86_SYNTH(33)) /* Number of synthetic 
features */
+
+#define X86_NR_SYNTH DIV_ROUND_UP(X86_FEATURE_nr - FSCAPINTS * 32, 32)
 
 /* Bug words follow the synthetic words. */
-#define X86_NR_BUG 1
 #define X86_BUG(x) ((FSCAPINTS + X86_NR_SYNTH) * 32 + (x))
 
 #define X86_BUG_FPU_PTRS          X86_BUG( 0) /* (F)X{SAVE,RSTOR} doesn't 
save/restore FOP/FIP/FDP. */
@@ -64,5 +65,10 @@ XEN_CPUFEATURE(XEN_REP_MOVSB,     X86_SYNTH(32)) /* REP 
MOVSB used for memcpy()
 #define X86_SPEC_BHB_LOOPS        X86_BUG(20) /* Use clear_bhb_loops for BHI 
mitigation.*/
 #define X86_SPEC_BHB_LOOPS_LONG   X86_BUG(21) /* Upgrade clear_bhb_loops to 
the "long" sequence. */
 
+#define X86_BUG_nr                X86_BUG(22) /* Number of bug identifiers */
+
+#define X86_NR_BUG DIV_ROUND_UP(X86_BUG_nr - (FSCAPINTS + X86_NR_SYNTH) * 32, \
+                                32)
+
 /* Total number of capability words, inc synth and bug words. */
 #define NCAPINTS (FSCAPINTS + X86_NR_SYNTH + X86_NR_BUG) /* N 32-bit words 
worth of info */
--
generated by git-patchbot for /home/xen/git/xen.git#master