[Devel] [PATCH RHEL10 COMMIT] fixup! arch/x86: introduce cpuid override

[Konstantin Khorenko]

The commit is pushed to "branch-rh10-6.12.0-55.52.1.5.x.vz10-ovz" and will appear at git at bitbucket.org:openvz/vzkernel.git
after rh10-6.12.0-55.52.1.5.29.vz10
------>
commit 8cd5cd3bc3da7260caababb0bf2e501159372ad8
Author: Vladimir Riabchun <vladimir.riabchun at virtuozzo.com>
Date:   Tue Jun 2 21:10:29 2026 +0000

    fixup! arch/x86: introduce cpuid override
    
    arch/x86/kernel/cpuid_fault.c:275:52: error: 'proc_vz_dir' undeclared
      275 |         proc = proc_create("cpuid_override", 0644, proc_vz_dir,
          |                                                    ^~~~~~~~~~~
    
    We have no proc_vz_dir without CONFIG_VE. For minimal logic change
    cover all the code in cpuid_fault.c except do_cpuid_fault
    with #ifdef CONFIG_VE.
    
    When CONFIG_VE is disabled, the behavior will be as if
    cpuid_override list is empty.
    
    https://virtuozzo.atlassian.net/browse/VSTOR-130116
    
    Feature: !CONFIG_VE build
    Signed-off-by: Vladimir Riabchun <vladimir.riabchun at virtuozzo.com>
    Reviewed-by: Vasileios Almpanis <vasileios.almpanis at virtuozzo.com>
---
 arch/x86/kernel/cpuid_fault.c | 64 +++++++++++++++++++++++++++----------------
 1 file changed, 40 insertions(+), 24 deletions(-)

diff --git a/arch/x86/kernel/cpuid_fault.c b/arch/x86/kernel/cpuid_fault.c
index ed5349b955f82..b50e52012a52b 100644
--- a/arch/x86/kernel/cpuid_fault.c
+++ b/arch/x86/kernel/cpuid_fault.c
@@ -20,6 +20,45 @@
 #include <asm/uaccess.h>
 #include <asm/traps.h>
 
+#ifdef CONFIG_VE
+static bool cpuid_override_match(unsigned int op, unsigned int count,
+				 unsigned int *eax, unsigned int *ebx,
+				 unsigned int *ecx, unsigned int *edx);
+
+#else
+static inline bool cpuid_override_match(unsigned int op, unsigned int count,
+					unsigned int *eax, unsigned int *ebx,
+					unsigned int *ecx, unsigned int *edx)
+{
+	return false;
+}
+#endif
+
+void __do_cpuid_fault(unsigned int op, unsigned int count,
+		      unsigned int *eax, unsigned int *ebx,
+		      unsigned int *ecx, unsigned int *edx)
+{
+	/* check if op is overridden */
+	if (cpuid_override_match(op, count, eax, ebx, ecx, edx))
+		return;
+
+	/* fallback to real cpuid */
+	cpuid_count(op, count, eax, ebx, ecx, edx);
+}
+
+void do_cpuid_fault(struct pt_regs *regs)
+{
+	unsigned int eax, ebx, ecx, edx;
+
+	__do_cpuid_fault(regs->ax, regs->cx, &eax, &ebx, &ecx, &edx);
+
+	regs->ax = eax;
+	regs->bx = ebx;
+	regs->cx = ecx;
+	regs->dx = edx;
+}
+
+#ifdef CONFIG_VE
 struct cpuid_override_table __rcu *cpuid_override __read_mostly;
 static DEFINE_SPINLOCK(cpuid_override_lock);
 
@@ -98,30 +137,6 @@ static bool cpuid_override_match(unsigned int op, unsigned int count,
 	return ret;
 }
 
-void __do_cpuid_fault(unsigned int op, unsigned int count,
-		      unsigned int *eax, unsigned int *ebx,
-		      unsigned int *ecx, unsigned int *edx)
-{
-	/* check if op is overridden */
-	if (cpuid_override_match(op, count, eax, ebx, ecx, edx))
-		return;
-
-	/* fallback to real cpuid */
-	cpuid_count(op, count, eax, ebx, ecx, edx);
-}
-
-void do_cpuid_fault(struct pt_regs *regs)
-{
-	unsigned int eax, ebx, ecx, edx;
-
-	__do_cpuid_fault(regs->ax, regs->cx, &eax, &ebx, &ecx, &edx);
-
-	regs->ax = eax;
-	regs->bx = ebx;
-	regs->cx = ecx;
-	regs->dx = edx;
-}
-
 /*
  * CPUID override entry format:
  *
@@ -280,3 +295,4 @@ static int __init cpuid_fault_init(void)
 	return 0;
 }
 module_init(cpuid_fault_init);
+#endif /* CONFIG_VE */