ppc/spapr: Use qemu_log_mask() for hcall_dprintf()

To see the output of the hcall_dprintf statements, you currently have
to enable the DEBUG_SPAPR_HCALLS macro in include/hw/ppc/spapr.h.
This is ugly because a) not every user who wants to debug guest
problems can or wants to recompile QEMU to be able to see such issues,
and b) since this macro is disabled by default, the code in the
hcall_dprintf() brackets tends to bitrot until somebody temporarily
enables that macro again.
Since the hcall_dprintf statements except one indicate guest
problems, let's always use qemu_log_mask(LOG_GUEST_ERROR, ...) for
this macro instead. One spot indicated an unimplemented host feature,
so this is changed into qemu_log_mask(LOG_UNIMP, ...) instead. Now
it's possible to see all those messages by simply adding the CLI
parameter "-d guest_errors,unimp", without the need to re-compile
the binary.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

hw/ppc/spapr_hcall.c

@@ -971,7 +971,8 @@ target_ulong spapr_hypercall(PowerPCCPU *cpu, target_ulong opcode,
         }
     }
 
-    hcall_dprintf("Unimplemented hcall 0x" TARGET_FMT_lx "\n", opcode);
+    qemu_log_mask(LOG_UNIMP, "Unimplemented SPAPR hcall 0x" TARGET_FMT_lx "\n",
+                  opcode);
     return H_FUNCTION;
 }
 

include/hw/ppc/spapr.h

@@ -353,15 +353,10 @@ typedef struct sPAPRDeviceTreeUpdateHeader {
     uint32_t version_id;
 } sPAPRDeviceTreeUpdateHeader;
 
-/*#define DEBUG_SPAPR_HCALLS*/
-
-#ifdef DEBUG_SPAPR_HCALLS
-#define hcall_dprintf(fmt, ...) \
-    do { fprintf(stderr, "%s: " fmt, __func__, ## __VA_ARGS__); } while (0)
-#else
 #define hcall_dprintf(fmt, ...) \
-    do { } while (0)
-#endif
+    do { \
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: " fmt, __func__, ## __VA_ARGS__); \
+    } while (0)
 
 typedef target_ulong (*spapr_hcall_fn)(PowerPCCPU *cpu, sPAPRMachineState *sm,
                                        target_ulong opcode,