qemu-log: introduce qemu_log_separate

In some cases, the same message is printed both on stderr and in the log.
Avoid duplicate output in the default case where stderr _is_ the log,
and standardize this to stderr+log where it used to use stdio+log.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

exec.c

@@ -870,7 +870,7 @@ void cpu_abort(CPUState *cpu, const char *fmt, ...)
     vfprintf(stderr, fmt, ap);
     fprintf(stderr, "\n");
     cpu_dump_state(cpu, stderr, fprintf, CPU_DUMP_FPU | CPU_DUMP_CCOP);
-    if (qemu_log_enabled()) {
+    if (qemu_log_separate()) {
         qemu_log("qemu: fatal: ");
         qemu_log_vprintf(fmt, ap2);
         qemu_log("\n");

include/qemu/log.h

@@ -28,6 +28,13 @@ static inline bool qemu_log_enabled(void)
     return qemu_logfile != NULL;
 }
 
+/* Returns true if qemu_log() will write somewhere else than stderr
+ */
+static inline bool qemu_log_separate(void)
+{
+    return qemu_logfile != NULL && qemu_logfile != stderr;
+}
+
 #define CPU_LOG_TB_OUT_ASM (1 << 0)
 #define CPU_LOG_TB_IN_ASM  (1 << 1)
 #define CPU_LOG_TB_OP      (1 << 2)

linux-user/main.c

@@ -1472,8 +1472,8 @@ do {                                                                    \
     CPUState *cs = ENV_GET_CPU(env);                                    \
     fprintf(stderr, fmt , ## __VA_ARGS__);                              \
     cpu_dump_state(cs, stderr, fprintf, 0);                             \
+    if (qemu_log_separate()) {                                          \
         qemu_log(fmt, ## __VA_ARGS__);                                  \
-    if (qemu_log_enabled()) {                                           \
         log_cpu_state(cs, 0);                                           \
     }                                                                   \
 } while (0)

target-cris/translate.c

@@ -130,8 +130,10 @@ typedef struct DisasContext {
 
 static void gen_BUG(DisasContext *dc, const char *file, int line)
 {
-    printf("BUG: pc=%x %s %d\n", dc->pc, file, line);
+    fprintf(stderr, "BUG: pc=%x %s %d\n", dc->pc, file, line);
+    if (qemu_log_separate()) {
         qemu_log("BUG: pc=%x %s %d\n", dc->pc, file, line);
+    }
     cpu_abort(CPU(dc->cpu), "%s:%d\n", file, line);
 }
 

target-ppc/excp_helper.c

@@ -131,12 +131,11 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
             /* Machine check exception is not enabled.
              * Enter checkstop state.
              */
-            if (qemu_log_enabled()) {
-                qemu_log("Machine check while not allowed. "
-                        "Entering checkstop state\n");
-            } else {
             fprintf(stderr, "Machine check while not allowed. "
                     "Entering checkstop state\n");
+            if (qemu_log_separate()) {
+                qemu_log("Machine check while not allowed. "
+                        "Entering checkstop state\n");
             }
             cs->halted = 1;
             cs->interrupt_request |= CPU_INTERRUPT_EXITTB;

target-ppc/translate.c

@@ -4285,19 +4285,23 @@ static inline void gen_op_mfspr(DisasContext *ctx)
              * allowing userland application to read the PVR
              */
             if (sprn != SPR_PVR) {
-                qemu_log("Trying to read privileged spr %d (0x%03x) at "
+                fprintf(stderr, "Trying to read privileged spr %d (0x%03x) at "
                         TARGET_FMT_lx "\n", sprn, sprn, ctx->nip - 4);
-                printf("Trying to read privileged spr %d (0x%03x) at "
+                if (qemu_log_separate()) {
+                    qemu_log("Trying to read privileged spr %d (0x%03x) at "
                              TARGET_FMT_lx "\n", sprn, sprn, ctx->nip - 4);
                 }
+            }
             gen_inval_exception(ctx, POWERPC_EXCP_PRIV_REG);
         }
     } else {
         /* Not defined */
-        qemu_log("Trying to read invalid spr %d (0x%03x) at "
+        fprintf(stderr, "Trying to read invalid spr %d (0x%03x) at "
                 TARGET_FMT_lx "\n", sprn, sprn, ctx->nip - 4);
-        printf("Trying to read invalid spr %d (0x%03x) at "
+        if (qemu_log_separate()) {
+            qemu_log("Trying to read invalid spr %d (0x%03x) at "
                      TARGET_FMT_lx "\n", sprn, sprn, ctx->nip - 4);
+        }
         gen_inval_exception(ctx, POWERPC_EXCP_INVAL_SPR);
     }
 }
@@ -4431,17 +4435,21 @@ static void gen_mtspr(DisasContext *ctx)
             (*write_cb)(ctx, sprn, rS(ctx->opcode));
         } else {
             /* Privilege exception */
-            qemu_log("Trying to write privileged spr %d (0x%03x) at "
+            fprintf(stderr, "Trying to write privileged spr %d (0x%03x) at "
                     TARGET_FMT_lx "\n", sprn, sprn, ctx->nip - 4);
-            printf("Trying to write privileged spr %d (0x%03x) at "
+            if (qemu_log_separate()) {
+                qemu_log("Trying to write privileged spr %d (0x%03x) at "
                          TARGET_FMT_lx "\n", sprn, sprn, ctx->nip - 4);
+            }
             gen_inval_exception(ctx, POWERPC_EXCP_PRIV_REG);
         }
     } else {
         /* Not defined */
+        if (qemu_log_separate()) {
             qemu_log("Trying to write invalid spr %d (0x%03x) at "
                      TARGET_FMT_lx "\n", sprn, sprn, ctx->nip - 4);
-        printf("Trying to write invalid spr %d (0x%03x) at "
+        }
+        fprintf(stderr, "Trying to write invalid spr %d (0x%03x) at "
                 TARGET_FMT_lx "\n", sprn, sprn, ctx->nip - 4);
         gen_inval_exception(ctx, POWERPC_EXCP_INVAL_SPR);
     }

target-s390x/helper.c

@@ -33,7 +33,7 @@
 #ifdef DEBUG_S390_STDOUT
 #define DPRINTF(fmt, ...) \
     do { fprintf(stderr, fmt, ## __VA_ARGS__); \
-         qemu_log(fmt, ##__VA_ARGS__); } while (0)
+         if (qemu_log_separate()) qemu_log(fmt, ##__VA_ARGS__); } while (0)
 #else
 #define DPRINTF(fmt, ...) \
     do { qemu_log(fmt, ## __VA_ARGS__); } while (0)

target-s390x/mmu_helper.c

@@ -30,7 +30,7 @@
 #ifdef DEBUG_S390_STDOUT
 #define DPRINTF(fmt, ...) \
     do { fprintf(stderr, fmt, ## __VA_ARGS__); \
-         qemu_log(fmt, ##__VA_ARGS__); } while (0)
+         if (qemu_log_separate()) qemu_log(fmt, ##__VA_ARGS__); } while (0)
 #else
 #define DPRINTF(fmt, ...) \
     do { qemu_log(fmt, ## __VA_ARGS__); } while (0)