From 3efe1a0f604cb7c4afd0381294acbdec75c65325 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Fri, 29 Aug 2025 10:43:44 +0200
Subject: [PATCH] target/i386: limit a20 to system emulation
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It is not used by user-mode emulation and is the only caller of
cpu_interrupt() in qemu-i386 and qemu-x86_64.

Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/i386/helper.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/target/i386/helper.c b/target/i386/helper.c
index e0aaed3c4c4..651041ccfa6 100644
--- a/target/i386/helper.c
+++ b/target/i386/helper.c
@@ -110,6 +110,7 @@ int cpu_x86_support_mca_broadcast(CPUX86State *env)
 /* x86 mmu */
 /* XXX: add PGE support */
 
+#ifndef CONFIG_USER_ONLY
 void x86_cpu_set_a20(X86CPU *cpu, int a20_state)
 {
     CPUX86State *env = &cpu->env;
@@ -129,6 +130,7 @@ void x86_cpu_set_a20(X86CPU *cpu, int a20_state)
         env->a20_mask = ~(1 << 20) | (a20_state << 20);
     }
 }
+#endif
 
 void cpu_x86_update_cr0(CPUX86State *env, uint32_t new_cr0)
 {
-- 
2.47.3