migration: Unify failure check for migrate_add_blocker()

Most callers check the return value.  Some check whether it set an
error.  Functionally equivalent, but the former tends to be easier on
the eyes, so do that everywhere.

Prior art: commit c6ecec43b2 "qemu-option: Check return value instead
of @err where convenient".

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210720125408.387910-10-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/backends/tpm/tpm_emulator.c b/backends/tpm/tpm_emulator.c
index e5f1063ab6c3cb5ad9d5e0bec2e470a9c77538e6..f8095d23d54d7508aa1aeefeacf1e44ea7060e2e 100644 (file)
--- a/backends/tpm/tpm_emulator.c
+++ b/backends/tpm/tpm_emulator.c
@@ -492,8 +492,7 @@ static int tpm_emulator_block_migration(TPMEmulator *tpm_emu)
         error_setg(&tpm_emu->migration_blocker,
                    "Migration disabled: TPM emulator does not support "
                    "migration");
-        migrate_add_blocker(tpm_emu->migration_blocker, &err);
-        if (err) {
+        if (migrate_add_blocker(tpm_emu->migration_blocker, &err) < 0) {
             error_report_err(err);
             error_free(tpm_emu->migration_blocker);
             tpm_emu->migration_blocker = NULL;

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index e8f85a5d2db19bec0b1673542fdea0b61a216102..dbbc6b6915b6bf0013f18b90446dc7fb4d6cd04f 100644 (file)
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1372,7 +1372,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
 
     if (hdev->migration_blocker != NULL) {
         r = migrate_add_blocker(hdev->migration_blocker, errp);
-        if (*errp) {
+        if (r < 0) {
             error_free(hdev->migration_blocker);
             goto fail_busyloop;
         }

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 57aed525b557e8eb0ecb4d51836b28b65947ebec..500d2e0e686f66cab8db3ee0a479984a08bd909a 100644 (file)
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -1435,7 +1435,7 @@ static int hyperv_init_vcpu(X86CPU *cpu)
                    "'hv-passthrough' CPU flag prevents migration, use explicit"
                    " set of hv-* flags instead");
         ret = migrate_add_blocker(hv_passthrough_mig_blocker, &local_err);
-        if (local_err) {
+        if (ret < 0) {
             error_report_err(local_err);
             return ret;
         }
@@ -1449,7 +1449,7 @@ static int hyperv_init_vcpu(X86CPU *cpu)
                    " make sure SMT is disabled and/or that vCPUs are properly"
                    " pinned)");
         ret = migrate_add_blocker(hv_no_nonarch_cs_mig_blocker, &local_err);
-        if (local_err) {
+        if (ret < 0) {
             error_report_err(local_err);
             return ret;
         }
@@ -1888,7 +1888,7 @@ int kvm_arch_init_vcpu(CPUState *cs)
                        "State blocked by non-migratable CPU device"
                        " (invtsc flag)");
             r = migrate_add_blocker(invtsc_mig_blocker, &local_err);
-            if (local_err) {
+            if (r < 0) {
                 error_report_err(local_err);
                 return r;
             }

diff --git a/target/i386/nvmm/nvmm-all.c b/target/i386/nvmm/nvmm-all.c
index 7bb0d9e30e308d09f1356452fdc1dbed06fcdce7..28dee4c5ee3fabe4d9107a314f9a4a337cae98a6 100644 (file)
--- a/target/i386/nvmm/nvmm-all.c
+++ b/target/i386/nvmm/nvmm-all.c
@@ -926,8 +926,7 @@ nvmm_init_vcpu(CPUState *cpu)
         error_setg(&nvmm_migration_blocker,
             "NVMM: Migration not supported");
 
-        (void)migrate_add_blocker(nvmm_migration_blocker, &local_error);
-        if (local_error) {
+        if (migrate_add_blocker(nvmm_migration_blocker, &local_error) < 0) {
             error_report_err(local_error);
             error_free(nvmm_migration_blocker);
             return -EINVAL;

diff --git a/target/i386/whpx/whpx-all.c b/target/i386/whpx/whpx-all.c
index cc8c0b984b144fc75a61afae75316433f00ac51a..3e925b9da70d6732cc674905dd596baf8d5a0e76 100644 (file)
--- a/target/i386/whpx/whpx-all.c
+++ b/target/i386/whpx/whpx-all.c
@@ -1346,8 +1346,7 @@ int whpx_init_vcpu(CPUState *cpu)
                "State blocked due to non-migratable CPUID feature support,"
                "dirty memory tracking support, and XSAVE/XRSTOR support");
 
-        (void)migrate_add_blocker(whpx_migration_blocker, &local_error);
-        if (local_error) {
+        if (migrate_add_blocker(whpx_migration_blocker, &local_error) < 0) {
             error_report_err(local_error);
             error_free(whpx_migration_blocker);
             ret = -EINVAL;