From 2eadc5c611ca8cc916f74c0f393f1fd942903ef7 Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Wed, 16 Oct 2019 10:29:31 +0800 Subject: [PATCH 6/8] migration: Change SaveStateEntry.instance_id into uint32_t It was always used as 32bit, so define it as used to be clear. Instead of using -1 as the auto-gen magic value, we switch to UINT32_MAX. We also make sure that we don't auto-gen this value to avoid overflowed instance IDs without being noticed. Suggested-by: Juan Quintela Signed-off-by: Peter Xu Reviewed-by: Juan Quintela Signed-off-by: Juan Quintela --- hw/intc/apic_common.c | 2 +- include/migration/register.h | 2 +- include/migration/vmstate.h | 2 +- migration/savevm.c | 18 ++++++++++-------- stubs/vmstate.c | 2 +- 5 files changed, 14 insertions(+), 12 deletions(-) diff --git a/hw/intc/apic_common.c b/hw/intc/apic_common.c index faea1af..07adba0 100644 --- a/hw/intc/apic_common.c +++ b/hw/intc/apic_common.c @@ -313,7 +313,7 @@ static void apic_common_realize(DeviceState *dev, Error **errp) APICCommonState *s = APIC_COMMON(dev); APICCommonClass *info; static DeviceState *vapic; - int instance_id = s->id; + uint32_t instance_id = s->id; info = APIC_COMMON_GET_CLASS(s); info->realize(dev, errp); diff --git a/include/migration/register.h b/include/migration/register.h index 3d0b983..8b2bc5b 100644 --- a/include/migration/register.h +++ b/include/migration/register.h @@ -70,7 +70,7 @@ typedef struct SaveVMHandlers { int register_savevm_live(DeviceState *dev, const char *idstr, - int instance_id, + uint32_t instance_id, int version_id, const SaveVMHandlers *ops, void *opaque); diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h index 92f531a..8abd2e3 100644 --- a/include/migration/vmstate.h +++ b/include/migration/vmstate.h @@ -1117,7 +1117,7 @@ bool vmstate_save_needed(const VMStateDescription *vmsd, void *opaque); #define VMSTATE_INSTANCE_ID_ANY -1 /* Returns: 0 on success, -1 on failure */ -int vmstate_register_with_alias_id(DeviceState *dev, int instance_id, +int vmstate_register_with_alias_id(DeviceState *dev, uint32_t instance_id, const VMStateDescription *vmsd, void *base, int alias_id, int required_for_version, diff --git a/migration/savevm.c b/migration/savevm.c index 62552ab..7d89c57 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -229,7 +229,7 @@ typedef struct CompatEntry { typedef struct SaveStateEntry { QTAILQ_ENTRY(SaveStateEntry) entry; char idstr[256]; - int instance_id; + uint32_t instance_id; int alias_id; int version_id; /* version id read from the stream */ @@ -616,10 +616,10 @@ void dump_vmstate_json_to_file(FILE *out_file) fclose(out_file); } -static int calculate_new_instance_id(const char *idstr) +static uint32_t calculate_new_instance_id(const char *idstr) { SaveStateEntry *se; - int instance_id = 0; + uint32_t instance_id = 0; QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { if (strcmp(idstr, se->idstr) == 0 @@ -627,6 +627,8 @@ static int calculate_new_instance_id(const char *idstr) instance_id = se->instance_id + 1; } } + /* Make sure we never loop over without being noticed */ + assert(instance_id != VMSTATE_INSTANCE_ID_ANY); return instance_id; } @@ -682,7 +684,7 @@ static void savevm_state_handler_insert(SaveStateEntry *nse) distinguishing id for all instances of your device class. */ int register_savevm_live(DeviceState *dev, const char *idstr, - int instance_id, + uint32_t instance_id, int version_id, const SaveVMHandlers *ops, void *opaque) @@ -756,7 +758,7 @@ void unregister_savevm(DeviceState *dev, const char *idstr, void *opaque) } } -int vmstate_register_with_alias_id(DeviceState *dev, int instance_id, +int vmstate_register_with_alias_id(DeviceState *dev, uint32_t instance_id, const VMStateDescription *vmsd, void *opaque, int alias_id, int required_for_version, @@ -1507,7 +1509,7 @@ int qemu_save_device_state(QEMUFile *f) return qemu_file_get_error(f); } -static SaveStateEntry *find_se(const char *idstr, int instance_id) +static SaveStateEntry *find_se(const char *idstr, uint32_t instance_id) { SaveStateEntry *se; @@ -2187,7 +2189,7 @@ qemu_loadvm_section_start_full(QEMUFile *f, MigrationIncomingState *mis) /* Find savevm section */ se = find_se(idstr, instance_id); if (se == NULL) { - error_report("Unknown savevm section or instance '%s' %d. " + error_report("Unknown savevm section or instance '%s' %"PRIu32". " "Make sure that your current VM setup matches your " "saved VM setup, including any hotplugged devices", idstr, instance_id); @@ -2211,7 +2213,7 @@ qemu_loadvm_section_start_full(QEMUFile *f, MigrationIncomingState *mis) ret = vmstate_load(f, se); if (ret < 0) { - error_report("error while loading state for instance 0x%x of" + error_report("error while loading state for instance 0x%"PRIx32" of" " device '%s'", instance_id, idstr); return ret; } diff --git a/stubs/vmstate.c b/stubs/vmstate.c index e1e89b8..4ed5cc6 100644 --- a/stubs/vmstate.c +++ b/stubs/vmstate.c @@ -4,7 +4,7 @@ const VMStateDescription vmstate_dummy = {}; int vmstate_register_with_alias_id(DeviceState *dev, - int instance_id, + uint32_t instance_id, const VMStateDescription *vmsd, void *base, int alias_id, int required_for_version, -- 1.8.3.1