migration: consolidate VMStateField.start

The member VMStateField.start is used for two things, partial data
migration for VBUFFER data (basically provide migration for a
sub-buffer) and for locating next in QTAILQ.

The implementation of the VBUFFER feature is broken when VMSTATE_ALLOC
is used. This however goes unnoticed because actually partial migration
for VBUFFER is not used at all.

Let's consolidate the usage of VMStateField.start by removing support
for partial migration for VBUFFER.
Signed-off-by: NHalil Pasic <pasic@linux.vnet.ibm.com>

Message-Id: <20170203175217.45562-1-pasic@linux.vnet.ibm.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

hw/char/exynos4210_uart.c

@@ -561,7 +561,7 @@ static const VMStateDescription vmstate_exynos4210_uart_fifo = {
     .fields = (VMStateField[]) {
         VMSTATE_UINT32(sp, Exynos4210UartFIFO),
         VMSTATE_UINT32(rp, Exynos4210UartFIFO),
-        VMSTATE_VBUFFER_UINT32(data, Exynos4210UartFIFO, 1, NULL, 0, size),
+        VMSTATE_VBUFFER_UINT32(data, Exynos4210UartFIFO, 1, NULL, size),
         VMSTATE_END_OF_LIST()
     }
 };

hw/display/g364fb.c

@@ -464,7 +464,7 @@ static const VMStateDescription vmstate_g364fb = {
     .minimum_version_id = 1,
     .post_load = g364fb_post_load,
     .fields = (VMStateField[]) {
-        VMSTATE_VBUFFER_UINT32(vram, G364State, 1, NULL, 0, vram_size),
+        VMSTATE_VBUFFER_UINT32(vram, G364State, 1, NULL, vram_size),
         VMSTATE_BUFFER_UNSAFE(color_palette, G364State, 0, 256 * 3),
         VMSTATE_BUFFER_UNSAFE(cursor_palette, G364State, 0, 9),
         VMSTATE_UINT16_ARRAY(cursor, G364State, 512),

hw/dma/pl330.c

@@ -173,8 +173,8 @@ static const VMStateDescription vmstate_pl330_fifo = {
     .version_id = 1,
     .minimum_version_id = 1,
     .fields = (VMStateField[]) {
-        VMSTATE_VBUFFER_UINT32(buf, PL330Fifo, 1, NULL, 0, buf_size),
-        VMSTATE_VBUFFER_UINT32(tag, PL330Fifo, 1, NULL, 0, buf_size),
+        VMSTATE_VBUFFER_UINT32(buf, PL330Fifo, 1, NULL, buf_size),
+        VMSTATE_VBUFFER_UINT32(tag, PL330Fifo, 1, NULL, buf_size),
         VMSTATE_UINT32(head, PL330Fifo),
         VMSTATE_UINT32(num, PL330Fifo),
         VMSTATE_UINT32(buf_size, PL330Fifo),
@@ -282,8 +282,8 @@ static const VMStateDescription vmstate_pl330 = {
         VMSTATE_STRUCT(manager, PL330State, 0, vmstate_pl330_chan, PL330Chan),
         VMSTATE_STRUCT_VARRAY_UINT32(chan, PL330State, num_chnls, 0,
                                      vmstate_pl330_chan, PL330Chan),
-        VMSTATE_VBUFFER_UINT32(lo_seqn, PL330State, 1, NULL, 0, num_chnls),
-        VMSTATE_VBUFFER_UINT32(hi_seqn, PL330State, 1, NULL, 0, num_chnls),
+        VMSTATE_VBUFFER_UINT32(lo_seqn, PL330State, 1, NULL, num_chnls),
+        VMSTATE_VBUFFER_UINT32(hi_seqn, PL330State, 1, NULL, num_chnls),
         VMSTATE_STRUCT(fifo, PL330State, 0, vmstate_pl330_fifo, PL330Fifo),
         VMSTATE_STRUCT(read_queue, PL330State, 0, vmstate_pl330_queue,
                        PL330Queue),

hw/intc/exynos4210_gic.c

@@ -393,7 +393,7 @@ static const VMStateDescription vmstate_exynos4210_irq_gate = {
     .version_id = 2,
     .minimum_version_id = 2,
     .fields = (VMStateField[]) {
-        VMSTATE_VBUFFER_UINT32(level, Exynos4210IRQGateState, 1, NULL, 0, n_in),
+        VMSTATE_VBUFFER_UINT32(level, Exynos4210IRQGateState, 1, NULL, n_in),
         VMSTATE_END_OF_LIST()
     }
 };

hw/ipmi/isa_ipmi_bt.c

@@ -471,10 +471,8 @@ static const VMStateDescription vmstate_ISAIPMIBTDevice = {
         VMSTATE_BOOL(bt.use_irq, ISAIPMIBTDevice),
         VMSTATE_BOOL(bt.irqs_enabled, ISAIPMIBTDevice),
         VMSTATE_UINT32(bt.outpos, ISAIPMIBTDevice),
-        VMSTATE_VBUFFER_UINT32(bt.outmsg, ISAIPMIBTDevice, 1, NULL, 0,
-                               bt.outlen),
-        VMSTATE_VBUFFER_UINT32(bt.inmsg, ISAIPMIBTDevice, 1, NULL, 0,
-                               bt.inlen),
+        VMSTATE_VBUFFER_UINT32(bt.outmsg, ISAIPMIBTDevice, 1, NULL, bt.outlen),
+        VMSTATE_VBUFFER_UINT32(bt.inmsg, ISAIPMIBTDevice, 1, NULL, bt.inlen),
         VMSTATE_UINT8(bt.control_reg, ISAIPMIBTDevice),
         VMSTATE_UINT8(bt.mask_reg, ISAIPMIBTDevice),
         VMSTATE_UINT8(bt.waiting_rsp, ISAIPMIBTDevice),

hw/net/vmxnet3.c

@@ -2397,7 +2397,7 @@ static const VMStateDescription vmxstate_vmxnet3_mcast_list = {
     .pre_load = vmxnet3_mcast_list_pre_load,
     .needed = vmxnet3_mc_list_needed,
     .fields = (VMStateField[]) {
-        VMSTATE_VBUFFER_UINT32(mcast_list, VMXNET3State, 0, NULL, 0,
+        VMSTATE_VBUFFER_UINT32(mcast_list, VMXNET3State, 0, NULL,
             mcast_list_buff_size),
         VMSTATE_END_OF_LIST()
     }

hw/nvram/mac_nvram.c

@@ -82,7 +82,7 @@ static const VMStateDescription vmstate_macio_nvram = {
     .version_id = 1,
     .minimum_version_id = 1,
     .fields = (VMStateField[]) {
-        VMSTATE_VBUFFER_UINT32(data, MacIONVRAMState, 0, NULL, 0, size),
+        VMSTATE_VBUFFER_UINT32(data, MacIONVRAMState, 0, NULL, size),
         VMSTATE_END_OF_LIST()
     }
 };

hw/nvram/spapr_nvram.c

@@ -224,7 +224,7 @@ static const VMStateDescription vmstate_spapr_nvram = {
     .post_load = spapr_nvram_post_load,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32(size, sPAPRNVRAM),
-        VMSTATE_VBUFFER_ALLOC_UINT32(buf, sPAPRNVRAM, 1, NULL, 0, size),
+        VMSTATE_VBUFFER_ALLOC_UINT32(buf, sPAPRNVRAM, 1, NULL, size),
         VMSTATE_END_OF_LIST()
     },
 };

hw/sd/sdhci.c

@@ -1253,7 +1253,7 @@ const VMStateDescription sdhci_vmstate = {
         VMSTATE_UINT16(data_count, SDHCIState),
         VMSTATE_UINT64(admasysaddr, SDHCIState),
         VMSTATE_UINT8(stopped_state, SDHCIState),
-        VMSTATE_VBUFFER_UINT32(fifo_buffer, SDHCIState, 1, NULL, 0, buf_maxsz),
+        VMSTATE_VBUFFER_UINT32(fifo_buffer, SDHCIState, 1, NULL, buf_maxsz),
         VMSTATE_TIMER_PTR(insert_timer, SDHCIState),
         VMSTATE_TIMER_PTR(transfer_timer, SDHCIState),
         VMSTATE_END_OF_LIST()

hw/timer/m48t59.c

@@ -563,7 +563,7 @@ static const VMStateDescription vmstate_m48t59 = {
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(lock, M48t59State),
         VMSTATE_UINT16(addr, M48t59State),
-        VMSTATE_VBUFFER_UINT32(buffer, M48t59State, 0, NULL, 0, size),
+        VMSTATE_VBUFFER_UINT32(buffer, M48t59State, 0, NULL, size),
         VMSTATE_END_OF_LIST()
     }
 };

include/migration/vmstate.h

@@ -587,7 +587,8 @@ extern const VMStateInfo vmstate_info_qtailq;
     .offset       = vmstate_offset_buffer(_state, _field) + _start,  \
 }
 
-#define VMSTATE_VBUFFER_MULTIPLY(_field, _state, _version, _test, _start, _field_size, _multiply) { \
+#define VMSTATE_VBUFFER_MULTIPLY(_field, _state, _version, _test,    \
+                                 _field_size, _multiply) {           \
     .name         = (stringify(_field)),                             \
     .version_id   = (_version),                                      \
     .field_exists = (_test),                                         \
@@ -596,10 +597,9 @@ extern const VMStateInfo vmstate_info_qtailq;
     .info         = &vmstate_info_buffer,                            \
     .flags        = VMS_VBUFFER|VMS_POINTER|VMS_MULTIPLY,            \
     .offset       = offsetof(_state, _field),                        \
-    .start        = (_start),                                        \
 }
 
-#define VMSTATE_VBUFFER(_field, _state, _version, _test, _start, _field_size) { \
+#define VMSTATE_VBUFFER(_field, _state, _version, _test, _field_size) { \
     .name         = (stringify(_field)),                             \
     .version_id   = (_version),                                      \
     .field_exists = (_test),                                         \
@@ -607,10 +607,9 @@ extern const VMStateInfo vmstate_info_qtailq;
     .info         = &vmstate_info_buffer,                            \
     .flags        = VMS_VBUFFER|VMS_POINTER,                         \
     .offset       = offsetof(_state, _field),                        \
-    .start        = (_start),                                        \
 }
 
-#define VMSTATE_VBUFFER_UINT32(_field, _state, _version, _test, _start, _field_size) { \
+#define VMSTATE_VBUFFER_UINT32(_field, _state, _version, _test, _field_size) { \
     .name         = (stringify(_field)),                             \
     .version_id   = (_version),                                      \
     .field_exists = (_test),                                         \
@@ -618,10 +617,10 @@ extern const VMStateInfo vmstate_info_qtailq;
     .info         = &vmstate_info_buffer,                            \
     .flags        = VMS_VBUFFER|VMS_POINTER,                         \
     .offset       = offsetof(_state, _field),                        \
-    .start        = (_start),                                        \
 }
 
-#define VMSTATE_VBUFFER_ALLOC_UINT32(_field, _state, _version, _test, _start, _field_size) { \
+#define VMSTATE_VBUFFER_ALLOC_UINT32(_field, _state, _version,       \
+                                     _test, _field_size) {           \
     .name         = (stringify(_field)),                             \
     .version_id   = (_version),                                      \
     .field_exists = (_test),                                         \
@@ -629,7 +628,6 @@ extern const VMStateInfo vmstate_info_qtailq;
     .info         = &vmstate_info_buffer,                            \
     .flags        = VMS_VBUFFER|VMS_POINTER|VMS_ALLOC,               \
     .offset       = offsetof(_state, _field),                        \
-    .start        = (_start),                                        \
 }
 
 #define VMSTATE_BUFFER_UNSAFE_INFO_TEST(_field, _state, _test, _version, _info, _size) { \
@@ -948,13 +946,10 @@ extern const VMStateInfo vmstate_info_qtailq;
     VMSTATE_BUFFER_START_MIDDLE_V(_f, _s, _start, 0)
 
 #define VMSTATE_PARTIAL_VBUFFER(_f, _s, _size)                        \
-    VMSTATE_VBUFFER(_f, _s, 0, NULL, 0, _size)
+    VMSTATE_VBUFFER(_f, _s, 0, NULL, _size)
 
 #define VMSTATE_PARTIAL_VBUFFER_UINT32(_f, _s, _size)                        \
-    VMSTATE_VBUFFER_UINT32(_f, _s, 0, NULL, 0, _size)
-
-#define VMSTATE_SUB_VBUFFER(_f, _s, _start, _size)                    \
-    VMSTATE_VBUFFER(_f, _s, 0, NULL, _start, _size)
+    VMSTATE_VBUFFER_UINT32(_f, _s, 0, NULL, _size)
 
 #define VMSTATE_BUFFER_TEST(_f, _s, _test)                            \
     VMSTATE_STATIC_BUFFER(_f, _s, 0, _test, 0, sizeof(typeof_field(_s, _f)))

migration/savevm.c

@@ -356,7 +356,7 @@ static const VMStateDescription vmstate_configuration = {
     .pre_save = configuration_pre_save,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32(len, SaveState),
-        VMSTATE_VBUFFER_ALLOC_UINT32(name, SaveState, 0, NULL, 0, len),
+        VMSTATE_VBUFFER_ALLOC_UINT32(name, SaveState, 0, NULL, len),
         VMSTATE_END_OF_LIST()
     },
     .subsections = (const VMStateDescription*[]) {

migration/vmstate.c

@@ -68,10 +68,10 @@ static void *vmstate_base_addr(void *opaque, VMStateField *field, bool alloc)
                 }
             }
             if (size) {
-                *((void **)base_addr + field->start) = g_malloc(size);
+                *(void **)base_addr = g_malloc(size);
             }
         }
-        base_addr = *(void **)base_addr + field->start;
+        base_addr = *(void **)base_addr;
     }
 
     return base_addr;

target/s390x/machine.c

@@ -180,7 +180,7 @@ const VMStateDescription vmstate_s390_cpu = {
         VMSTATE_UINT8(env.cpu_state, S390CPU),
         VMSTATE_UINT8(env.sigp_order, S390CPU),
         VMSTATE_UINT32_V(irqstate_saved_size, S390CPU, 4),
-        VMSTATE_VBUFFER_UINT32(irqstate, S390CPU, 4, NULL, 0,
+        VMSTATE_VBUFFER_UINT32(irqstate, S390CPU, 4, NULL,
                                irqstate_saved_size),
         VMSTATE_END_OF_LIST()
     },

util/fifo8.c

@@ -118,7 +118,7 @@ const VMStateDescription vmstate_fifo8 = {
     .version_id = 1,
     .minimum_version_id = 1,
     .fields = (VMStateField[]) {
-        VMSTATE_VBUFFER_UINT32(data, Fifo8, 1, NULL, 0, capacity),
+        VMSTATE_VBUFFER_UINT32(data, Fifo8, 1, NULL, capacity),
         VMSTATE_UINT32(head, Fifo8),
         VMSTATE_UINT32(num, Fifo8),
         VMSTATE_END_OF_LIST()