diff --git a/target-i386/helper.c b/target-i386/helper.c
index 4bf9db7..696e4e1 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -26,6 +26,22 @@
 
 //#define DEBUG_MMU
 
+#ifdef DEBUG_MMU
+static const bool debug_mmu = true;
+#else
+static const bool debug_mmu;
+#endif
+
+static void GCC_FMT_ATTR(1, 2) mmu_dprintf(const char *fmt, ...)
+{
+    if (debug_mmu) {
+        va_list ap;
+        va_start(ap, fmt);
+        vprintf(fmt, ap);
+        va_end(ap);
+    }
+}
+
 static void cpu_x86_version(CPUX86State *env, int *family, int *model)
 {
     int cpuver = env->cpuid_version;
@@ -372,9 +388,8 @@ void x86_cpu_set_a20(X86CPU *cpu, int a20_state)
 
     a20_state = (a20_state != 0);
     if (a20_state != ((env->a20_mask >> 20) & 1)) {
-#if defined(DEBUG_MMU)
-        printf("A20 update: a20=%d\n", a20_state);
-#endif
+        mmu_dprintf("A20 update: a20=%d\n", a20_state);
+
         /* if the cpu is currently executing code, we must unlink it and
            all the potentially executing TB */
         cpu_interrupt(env, CPU_INTERRUPT_EXITTB);
@@ -390,9 +405,8 @@ void cpu_x86_update_cr0(CPUX86State *env, uint32_t new_cr0)
 {
     int pe_state;
 
-#if defined(DEBUG_MMU)
-    printf("CR0 update: CR0=0x%08x\n", new_cr0);
-#endif
+    mmu_dprintf("CR0 update: CR0=0x%08x\n", new_cr0);
+
     if ((new_cr0 & (CR0_PG_MASK | CR0_WP_MASK | CR0_PE_MASK)) !=
         (env->cr[0] & (CR0_PG_MASK | CR0_WP_MASK | CR0_PE_MASK))) {
         tlb_flush(env, 1);
@@ -433,18 +447,15 @@ void cpu_x86_update_cr3(CPUX86State *env, target_ulong new_cr3)
 {
     env->cr[3] = new_cr3;
     if (env->cr[0] & CR0_PG_MASK) {
-#if defined(DEBUG_MMU)
-        printf("CR3 update: CR3=" TARGET_FMT_lx "\n", new_cr3);
-#endif
+        mmu_dprintf("CR3 update: CR3=" TARGET_FMT_lx "\n", new_cr3);
         tlb_flush(env, 0);
     }
 }
 
 void cpu_x86_update_cr4(CPUX86State *env, uint32_t new_cr4)
 {
-#if defined(DEBUG_MMU)
-    printf("CR4 update: CR4=%08x\n", (uint32_t)env->cr[4]);
-#endif
+    mmu_dprintf("CR4 update: CR4=%08x\n", (uint32_t)env->cr[4]);
+
     if ((new_cr4 ^ env->cr[4]) &
         (CR4_PGE_MASK | CR4_PAE_MASK | CR4_PSE_MASK |
          CR4_SMEP_MASK | CR4_SMAP_MASK)) {
@@ -510,10 +521,9 @@ int cpu_x86_handle_mmu_fault(CPUX86State *env, target_ulong addr,
     target_ulong vaddr, virt_addr;
 
     is_user = mmu_idx == MMU_USER_IDX;
-#if defined(DEBUG_MMU)
-    printf("MMU fault: addr=" TARGET_FMT_lx " w=%d u=%d eip=" TARGET_FMT_lx "\n",
-           addr, is_write1, is_user, env->eip);
-#endif
+    mmu_dprintf("MMU fault: addr=" TARGET_FMT_lx " w=%d u=%d"
+                " eip=" TARGET_FMT_lx "\n",
+                addr, is_write1, is_user, env->eip);
     is_write = is_write1 & 1;
 
     if (!(env->cr[0] & CR0_PG_MASK)) {
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 0cf413d..9cbef77 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -37,13 +37,21 @@
 //#define DEBUG_KVM
 
 #ifdef DEBUG_KVM
-#define DPRINTF(fmt, ...) \
-    do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
+static const bool debug_kvm = true;
 #else
-#define DPRINTF(fmt, ...) \
-    do { } while (0)
+static const bool debug_kvm;
 #endif
 
+static void GCC_FMT_ATTR(1, 2) DPRINTF(const char *fmt, ...)
+{
+    if (debug_kvm) {
+        va_list ap;
+        va_start(ap, fmt);
+        vfprintf(stderr, fmt, ap);
+        va_end(ap);
+    }
+}
+
 #define MSR_KVM_WALL_CLOCK  0x11
 #define MSR_KVM_SYSTEM_TIME 0x12
 
diff --git a/target-i386/seg_helper.c b/target-i386/seg_helper.c
index 3247dee..2338d54 100644
--- a/target-i386/seg_helper.c
+++ b/target-i386/seg_helper.c
@@ -29,14 +29,28 @@
 #endif /* !defined(CONFIG_USER_ONLY) */
 
 #ifdef DEBUG_PCALL
-# define LOG_PCALL(...) qemu_log_mask(CPU_LOG_PCALL, ## __VA_ARGS__)
-# define LOG_PCALL_STATE(env)                                  \
-    log_cpu_state_mask(CPU_LOG_PCALL, (env), CPU_DUMP_CCOP)
+static const bool debug_pcall = true;
 #else
-# define LOG_PCALL(...) do { } while (0)
-# define LOG_PCALL_STATE(env) do { } while (0)
+static const bool debug_pcall;
 #endif
 
+static void GCC_FMT_ATTR(1, 2) LOG_PCALL(const char *fmt, ...)
+{
+    if (debug_pcall) {
+        va_list ap;
+        va_start(ap, fmt);
+        qemu_log_mask(CPU_LOG_PCALL, fmt, ap);
+        va_end(ap);
+    }
+}
+
+static inline void LOG_PCALL_STATE(CPUX86State *env)
+{
+    if (debug_pcall) {
+        log_cpu_state_mask(CPU_LOG_PCALL, (env), CPU_DUMP_CCOP);
+    }
+}
+
 /* return non zero if error */
 static inline int load_segment(CPUX86State *env, uint32_t *e1_ptr,
                                uint32_t *e2_ptr, int selector)
