diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index d7da28fada87..a5a4944ce5d1 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -335,6 +335,22 @@ static inline int alternatives_text_reserved(void *start, void *end)
  */
 #define ASM_NO_INPUT_CLOBBER(clbr...) "i" (0) : clbr
 
+/* Macro for creating assembler functions avoiding any C magic. */
+#define DEFINE_ASM_FUNC(func, instr, sec)		\
+	asm (".pushsection " #sec ", \"ax\"\n"		\
+	     ".global " #func "\n\t"			\
+	     ".type " #func ", @function\n\t"		\
+	     ASM_FUNC_ALIGN "\n"			\
+	     #func ":\n\t"				\
+	     ASM_ENDBR					\
+	     instr "\n\t"				\
+	     ASM_RET					\
+	     ".size " #func ", . - " #func "\n\t"	\
+	     ".popsection")
+
+void x86_BUG(void);
+void x86_nop(void);
+
 #else /* __ASSEMBLY__ */
 
 #ifdef CONFIG_SMP
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index b49778664d2b..3474dac4607d 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -726,18 +726,6 @@ static __always_inline unsigned long arch_local_irq_save(void)
 #undef PVOP_VCALL4
 #undef PVOP_CALL4
 
-#define DEFINE_PARAVIRT_ASM(func, instr, sec)		\
-	asm (".pushsection " #sec ", \"ax\"\n"		\
-	     ".global " #func "\n\t"			\
-	     ".type " #func ", @function\n\t"		\
-	     ASM_FUNC_ALIGN "\n"			\
-	     #func ":\n\t"				\
-	     ASM_ENDBR					\
-	     instr "\n\t"				\
-	     ASM_RET					\
-	     ".size " #func ", . - " #func "\n\t"	\
-	     ".popsection")
-
 extern void default_banner(void);
 
 #else  /* __ASSEMBLY__ */
diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index 4acbcddddc29..fe58f1882e9c 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -557,8 +557,6 @@ void paravirt_enter_lazy_mmu(void);
 void paravirt_leave_lazy_mmu(void);
 void paravirt_flush_lazy_mmu(void);
 
-void _paravirt_nop(void);
-void paravirt_BUG(void);
 unsigned long paravirt_ret0(void);
 #ifdef CONFIG_PARAVIRT_XXL
 u64 _paravirt_ident_64(u64);
@@ -568,7 +566,7 @@ void pv_native_irq_enable(void);
 unsigned long pv_native_read_cr2(void);
 #endif
 
-#define paravirt_nop	((void *)_paravirt_nop)
+#define paravirt_nop	((void *)x86_nop)
 
 extern struct paravirt_patch_site __parainstructions[],
 	__parainstructions_end[];
diff --git a/arch/x86/include/asm/qspinlock_paravirt.h b/arch/x86/include/asm/qspinlock_paravirt.h
index 42b17cf10b10..2189b3379b1c 100644
--- a/arch/x86/include/asm/qspinlock_paravirt.h
+++ b/arch/x86/include/asm/qspinlock_paravirt.h
@@ -54,8 +54,8 @@ __PV_CALLEE_SAVE_REGS_THUNK(__pv_queued_spin_unlock_slowpath, ".spinlock.text");
 	"pop    %rdx\n\t"						\
 	FRAME_END
 
-DEFINE_PARAVIRT_ASM(__raw_callee_save___pv_queued_spin_unlock,
-		    PV_UNLOCK_ASM, .spinlock.text);
+DEFINE_ASM_FUNC(__raw_callee_save___pv_queued_spin_unlock,
+		PV_UNLOCK_ASM, .spinlock.text);
 
 #else /* CONFIG_64BIT */
 
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index f615e0cb6d93..b7c70479fe58 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -253,6 +253,16 @@ static void __init_or_module noinline optimize_nops(u8 *instr, size_t len)
 	}
 }
 
+/* Low-level backend functions usable from alternative code replacements. */
+DEFINE_ASM_FUNC(x86_nop, "", .entry.text);
+EXPORT_SYMBOL_GPL(x86_nop);
+
+noinstr void x86_BUG(void)
+{
+	BUG();
+}
+EXPORT_SYMBOL_GPL(x86_BUG);
+
 /*
  * Replace instructions with better alternatives for this CPU type. This runs
  * before SMP is initialized to avoid SMP problems with self modifying code.
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 1cceac5984da..d025fc630115 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -803,8 +803,8 @@ extern bool __raw_callee_save___kvm_vcpu_is_preempted(long);
  "cmpb   $0, " __stringify(KVM_STEAL_TIME_preempted) "+steal_time(%rax)\n\t" \
  "setne  %al\n\t"
 
-DEFINE_PARAVIRT_ASM(__raw_callee_save___kvm_vcpu_is_preempted,
-		    PV_VCPU_PREEMPTED_ASM, .text);
+DEFINE_ASM_FUNC(__raw_callee_save___kvm_vcpu_is_preempted,
+		PV_VCPU_PREEMPTED_ASM, .text);
 #endif
 
 static void __init kvm_guest_init(void)
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index ac10b46c5832..dfad56679f88 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -34,14 +34,8 @@
 #include <asm/io_bitmap.h>
 #include <asm/gsseg.h>
 
-/*
- * nop stub, which must not clobber anything *including the stack* to
- * avoid confusing the entry prologues.
- */
-DEFINE_PARAVIRT_ASM(_paravirt_nop, "", .entry.text);
-
 /* stub always returning 0. */
-DEFINE_PARAVIRT_ASM(paravirt_ret0, "xor %eax,%eax", .entry.text);
+DEFINE_ASM_FUNC(paravirt_ret0, "xor %eax,%eax", .entry.text);
 
 void __init default_banner(void)
 {
@@ -49,12 +43,6 @@ void __init default_banner(void)
 	       pv_info.name);
 }
 
-/* Undefined instruction for dealing with missing ops pointers. */
-noinstr void paravirt_BUG(void)
-{
-	BUG();
-}
-
 static unsigned paravirt_patch_call(void *insn_buff, const void *target,
 				    unsigned long addr, unsigned len)
 {
@@ -64,11 +52,11 @@ static unsigned paravirt_patch_call(void *insn_buff, const void *target,
 }
 
 #ifdef CONFIG_PARAVIRT_XXL
-DEFINE_PARAVIRT_ASM(_paravirt_ident_64, "mov %rdi, %rax", .text);
-DEFINE_PARAVIRT_ASM(pv_native_save_fl, "pushf; pop %rax", .noinstr.text);
-DEFINE_PARAVIRT_ASM(pv_native_irq_disable, "cli", .noinstr.text);
-DEFINE_PARAVIRT_ASM(pv_native_irq_enable, "sti", .noinstr.text);
-DEFINE_PARAVIRT_ASM(pv_native_read_cr2, "mov %cr2, %rax", .noinstr.text);
+DEFINE_ASM_FUNC(_paravirt_ident_64, "mov %rdi, %rax", .text);
+DEFINE_ASM_FUNC(pv_native_save_fl, "pushf; pop %rax", .noinstr.text);
+DEFINE_ASM_FUNC(pv_native_irq_disable, "cli", .noinstr.text);
+DEFINE_ASM_FUNC(pv_native_irq_enable, "sti", .noinstr.text);
+DEFINE_ASM_FUNC(pv_native_read_cr2, "mov %cr2, %rax", .noinstr.text);
 #endif
 
 DEFINE_STATIC_KEY_TRUE(virt_spin_lock_key);
@@ -90,9 +78,9 @@ unsigned int paravirt_patch(u8 type, void *insn_buff, unsigned long addr,
 	unsigned ret;
 
 	if (opfunc == NULL)
-		/* If there's no function, patch it with paravirt_BUG() */
-		ret = paravirt_patch_call(insn_buff, paravirt_BUG, addr, len);
-	else if (opfunc == _paravirt_nop)
+		/* If there's no function, patch it with x86_BUG() */
+		ret = paravirt_patch_call(insn_buff, x86_BUG, addr, len);
+	else if (opfunc == x86_nop)
 		ret = 0;
 	else
 		/* Otherwise call the function. */
diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
index 6092fea7d651..5d132f5a5d7d 100644
--- a/arch/x86/xen/irq.c
+++ b/arch/x86/xen/irq.c
@@ -45,7 +45,7 @@ static const typeof(pv_ops) xen_irq_ops __initconst = {
 		/* Initial interrupt flag handling only called while interrupts off. */
 		.save_fl = __PV_IS_CALLEE_SAVE(paravirt_ret0),
 		.irq_disable = __PV_IS_CALLEE_SAVE(paravirt_nop),
-		.irq_enable = __PV_IS_CALLEE_SAVE(paravirt_BUG),
+		.irq_enable = __PV_IS_CALLEE_SAVE(x86_BUG),
 
 		.safe_halt = xen_safe_halt,
 		.halt = xen_halt,
