migration: pre_save return int

Modify the pre_save method on VMStateDescription to return an int
rather than void so that it potentially can fail.

Changed zillions of devices to make them return 0; the only
case I've made it return non-0 is hw/intc/s390_flic_kvm.c that already
had an error_report/return case.

Note: If you add an error exit in your pre_save you must emit
an error_report to say why.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20170925112917.21340-2-dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

5 files changed, 17 insertions, 6 deletions

diff --git a/target/arm/machine.c b/target/arm/machine.c
index e5fe083da4..29df7ac87d 100644
--- a/target/arm/machine.c
+++ b/target/arm/machine.c
@@ -394,7 +394,7 @@ static const VMStateInfo vmstate_powered_off = {
     .put = put_power,
 };
 
-static void cpu_pre_save(void *opaque)
+static int cpu_pre_save(void *opaque)
 {
     ARMCPU *cpu = opaque;
 
@@ -415,6 +415,8 @@ static void cpu_pre_save(void *opaque)
            cpu->cpreg_array_len * sizeof(uint64_t));
     memcpy(cpu->cpreg_vmstate_values, cpu->cpreg_values,
            cpu->cpreg_array_len * sizeof(uint64_t));
+
+    return 0;
 }
 
 static int cpu_post_load(void *opaque, int version_id)
diff --git a/target/i386/machine.c b/target/i386/machine.c
index 29cc58eda9..df5ec359eb 100644
--- a/target/i386/machine.c
+++ b/target/i386/machine.c
@@ -160,13 +160,15 @@ static floatx80 cpu_set_fp80(uint64_t mant, uint16_t upper)
     return temp.d;
 }
 
-static void fpreg_pre_save(void *opaque)
+static int fpreg_pre_save(void *opaque)
 {
     x86_FPReg_tmp *tmp = opaque;
 
     /* we save the real CPU data (in case of MMX usage only 'mant'
        contains the MMX register */
     cpu_get_fp80(&tmp->tmp_mant, &tmp->tmp_exp, tmp->parent->d);
+
+    return 0;
 }
 
 static int fpreg_post_load(void *opaque, int version)
@@ -196,7 +198,7 @@ static const VMStateDescription vmstate_fpreg = {
     }
 };
 
-static void cpu_pre_save(void *opaque)
+static int cpu_pre_save(void *opaque)
 {
     X86CPU *cpu = opaque;
     CPUX86State *env = &cpu->env;
@@ -228,6 +230,7 @@ static void cpu_pre_save(void *opaque)
         env->segs[R_SS].flags &= ~(env->segs[R_SS].flags & DESC_DPL_MASK);
     }
 
+    return 0;
 }
 
 static int cpu_post_load(void *opaque, int version_id)
diff --git a/target/ppc/machine.c b/target/ppc/machine.c
index e36b7100cb..384caee800 100644
--- a/target/ppc/machine.c
+++ b/target/ppc/machine.c
@@ -146,7 +146,7 @@ static bool cpu_pre_2_8_migration(void *opaque, int version_id)
     return cpu->pre_2_8_migration;
 }
 
-static void cpu_pre_save(void *opaque)
+static int cpu_pre_save(void *opaque)
 {
     PowerPCCPU *cpu = opaque;
     CPUPPCState *env = &cpu->env;
@@ -195,6 +195,8 @@ static void cpu_pre_save(void *opaque)
         cpu->mig_insns_flags2 = env->insns_flags2 & insns_compat_mask2;
         cpu->mig_nb_BATs = env->nb_BATs;
     }
+
+    return 0;
 }
 
 /*
diff --git a/target/s390x/machine.c b/target/s390x/machine.c
index 097a147dbb..e1b7015d20 100644
--- a/target/s390x/machine.c
+++ b/target/s390x/machine.c
@@ -37,13 +37,15 @@ static int cpu_post_load(void *opaque, int version_id)
     return 0;
 }
 
-static void cpu_pre_save(void *opaque)
+static int cpu_pre_save(void *opaque)
 {
     S390CPU *cpu = opaque;
 
     if (kvm_enabled()) {
         kvm_s390_vcpu_interrupt_pre_save(cpu);
     }
+
+    return 0;
 }
 
 static inline bool fpu_needed(void *opaque)
diff --git a/target/sparc/machine.c b/target/sparc/machine.c
index 6bd6b8ee3e..8ff9dea297 100644
--- a/target/sparc/machine.c
+++ b/target/sparc/machine.c
@@ -88,7 +88,7 @@ static const VMStateInfo vmstate_psr = {
     .put = put_psr,
 };
 
-static void cpu_pre_save(void *opaque)
+static int cpu_pre_save(void *opaque)
 {
     SPARCCPU *cpu = opaque;
     CPUSPARCState *env = &cpu->env;
@@ -97,6 +97,8 @@ static void cpu_pre_save(void *opaque)
      * window as the outs of the first window
      */
     cpu_set_cwp(env, env->cwp);
+
+    return 0;
 }
 
 /* 32-bit SPARC retains migration compatibility with older versions