[Qemu-devel] [RFC] PCI/migration merge vmstate_pci_device and vmstate_pcie_device

["Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

The vmstate_pci_device and vmstate_pcie_devices differ
just in the size of one buffer; combine the two using a _TEST
macro.

I think this is safe as long as everywhere which currently
uses either of these two uses the right type.

One thing that concerns me is that some places use pci_device_load/save
which does some irq mangling, but others just use the VMSTATE_PCI_DEVICE
macro - how are they getting the same irq mangling?

This passes a smoke test migrate of:
./x86_64-softmmu/qemu-system-x86_64 -M pc,accel=kvm -m 1024
./littlefed20.img -device e1000e -device virtio-net -device
e1000 -device virtio-rng -device megasas -device megasas-gen2 -device
ioh3420 -device nec-usb-xhci

to an unmodified qemu.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 hw/net/e1000e.c                    |  2 +-
 hw/net/vmxnet3.c                   |  2 +-
 hw/pci-bridge/ioh3420.c            |  2 +-
 hw/pci-bridge/xio3130_downstream.c |  2 +-
 hw/pci-bridge/xio3130_upstream.c   |  2 +-
 hw/pci/pci.c                       | 41 +++++++++++++++++---------------------
 hw/scsi/megasas.c                  |  2 +-
 hw/scsi/vmw_pvscsi.c               |  2 +-
 hw/usb/hcd-xhci.c                  |  2 +-
 include/hw/pci/pcie.h              | 10 ----------
 10 files changed, 26 insertions(+), 41 deletions(-)

diff --git a/hw/net/e1000e.c b/hw/net/e1000e.c
index 4994e1c..463ac9b 100644
--- a/hw/net/e1000e.c
+++ b/hw/net/e1000e.c
@@ -592,7 +592,7 @@ static const VMStateDescription e1000e_vmstate = {
     .pre_save = e1000e_pre_save,
     .post_load = e1000e_post_load,
     .fields = (VMStateField[]) {
-        VMSTATE_PCIE_DEVICE(parent_obj, E1000EState),
+        VMSTATE_PCI_DEVICE(parent_obj, E1000EState),
         VMSTATE_MSIX(parent_obj, E1000EState),
 
         VMSTATE_UINT32(ioaddr, E1000EState),
diff --git a/hw/net/vmxnet3.c b/hw/net/vmxnet3.c
index bbb898b..86cded9 100644
--- a/hw/net/vmxnet3.c
+++ b/hw/net/vmxnet3.c
@@ -2538,7 +2538,7 @@ static const VMStateDescription vmstate_vmxnet3_pcie_device = {
     .minimum_version_id = 1,
     .needed = vmxnet3_vmstate_need_pcie_device,
     .fields = (VMStateField[]) {
-        VMSTATE_PCIE_DEVICE(parent_obj, VMXNET3State),
+        VMSTATE_PCI_DEVICE(parent_obj, VMXNET3State),
         VMSTATE_END_OF_LIST()
     }
 };
diff --git a/hw/pci-bridge/ioh3420.c b/hw/pci-bridge/ioh3420.c
index c8b5ac4..98114e1 100644
--- a/hw/pci-bridge/ioh3420.c
+++ b/hw/pci-bridge/ioh3420.c
@@ -178,7 +178,7 @@ static const VMStateDescription vmstate_ioh3420 = {
     .minimum_version_id = 1,
     .post_load = pcie_cap_slot_post_load,
     .fields = (VMStateField[]) {
-        VMSTATE_PCIE_DEVICE(parent_obj.parent_obj.parent_obj, PCIESlot),
+        VMSTATE_PCI_DEVICE(parent_obj.parent_obj.parent_obj, PCIESlot),
         VMSTATE_STRUCT(parent_obj.parent_obj.parent_obj.exp.aer_log,
                        PCIESlot, 0, vmstate_pcie_aer_log, PCIEAERLog),
         VMSTATE_END_OF_LIST()
diff --git a/hw/pci-bridge/xio3130_downstream.c b/hw/pci-bridge/xio3130_downstream.c
index cef6e13..4c54301 100644
--- a/hw/pci-bridge/xio3130_downstream.c
+++ b/hw/pci-bridge/xio3130_downstream.c
@@ -164,7 +164,7 @@ static const VMStateDescription vmstate_xio3130_downstream = {
     .minimum_version_id = 1,
     .post_load = pcie_cap_slot_post_load,
     .fields = (VMStateField[]) {
-        VMSTATE_PCIE_DEVICE(parent_obj.parent_obj.parent_obj, PCIESlot),
+        VMSTATE_PCI_DEVICE(parent_obj.parent_obj.parent_obj, PCIESlot),
         VMSTATE_STRUCT(parent_obj.parent_obj.parent_obj.exp.aer_log,
                        PCIESlot, 0, vmstate_pcie_aer_log, PCIEAERLog),
         VMSTATE_END_OF_LIST()
diff --git a/hw/pci-bridge/xio3130_upstream.c b/hw/pci-bridge/xio3130_upstream.c
index 4ad0440..45dbd1c 100644
--- a/hw/pci-bridge/xio3130_upstream.c
+++ b/hw/pci-bridge/xio3130_upstream.c
@@ -136,7 +136,7 @@ static const VMStateDescription vmstate_xio3130_upstream = {
     .version_id = 1,
     .minimum_version_id = 1,
     .fields = (VMStateField[]) {
-        VMSTATE_PCIE_DEVICE(parent_obj.parent_obj, PCIEPort),
+        VMSTATE_PCI_DEVICE(parent_obj.parent_obj, PCIEPort),
         VMSTATE_STRUCT(parent_obj.parent_obj.exp.aer_log, PCIEPort, 0,
                        vmstate_pcie_aer_log, PCIEAERLog),
         VMSTATE_END_OF_LIST()
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 16df188..8e4226b 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -542,30 +542,29 @@ static VMStateInfo vmstate_info_pci_irq_state = {
     .put  = put_pci_irq_state,
 };
 
+static bool migrate_is_pcie(void *opaque, int version_id)
+{
+    return pci_is_express((PCIDevice *)opaque);
+}
+
+static bool migrate_is_not_pcie(void *opaque, int version_id)
+{
+    return !pci_is_express((PCIDevice *)opaque);
+}
+
 const VMStateDescription vmstate_pci_device = {
     .name = "PCIDevice",
     .version_id = 2,
     .minimum_version_id = 1,
     .fields = (VMStateField[]) {
         VMSTATE_INT32_POSITIVE_LE(version_id, PCIDevice),
-        VMSTATE_BUFFER_UNSAFE_INFO(config, PCIDevice, 0,
-                                   vmstate_info_pci_config,
+        VMSTATE_BUFFER_UNSAFE_INFO_TEST(config, PCIDevice,
+                                   migrate_is_not_pcie,
+                                   0, vmstate_info_pci_config,
                                    PCI_CONFIG_SPACE_SIZE),
-        VMSTATE_BUFFER_UNSAFE_INFO(irq_state, PCIDevice, 2,
-				   vmstate_info_pci_irq_state,
-				   PCI_NUM_PINS * sizeof(int32_t)),
-        VMSTATE_END_OF_LIST()
-    }
-};
-
-const VMStateDescription vmstate_pcie_device = {
-    .name = "PCIEDevice",
-    .version_id = 2,
-    .minimum_version_id = 1,
-    .fields = (VMStateField[]) {
-        VMSTATE_INT32_POSITIVE_LE(version_id, PCIDevice),
-        VMSTATE_BUFFER_UNSAFE_INFO(config, PCIDevice, 0,
-                                   vmstate_info_pci_config,
+        VMSTATE_BUFFER_UNSAFE_INFO_TEST(config, PCIDevice,
+                                   migrate_is_pcie,
+                                   0, vmstate_info_pci_config,
                                    PCIE_CONFIG_SPACE_SIZE),
         VMSTATE_BUFFER_UNSAFE_INFO(irq_state, PCIDevice, 2,
 				   vmstate_info_pci_irq_state,
@@ -574,10 +573,6 @@ const VMStateDescription vmstate_pcie_device = {
     }
 };
 
-static inline const VMStateDescription *pci_get_vmstate(PCIDevice *s)
-{
-    return pci_is_express(s) ? &vmstate_pcie_device : &vmstate_pci_device;
-}
 
 void pci_device_save(PCIDevice *s, QEMUFile *f)
 {
@@ -586,7 +581,7 @@ void pci_device_save(PCIDevice *s, QEMUFile *f)
      * This makes us compatible with old devices
      * which never set or clear this bit. */
     s->config[PCI_STATUS] &= ~PCI_STATUS_INTERRUPT;
-    vmstate_save_state(f, pci_get_vmstate(s), s, NULL);
+    vmstate_save_state(f, &vmstate_pci_device, s, NULL);
     /* Restore the interrupt status bit. */
     pci_update_irq_status(s);
 }
@@ -594,7 +589,7 @@ void pci_device_save(PCIDevice *s, QEMUFile *f)
 int pci_device_load(PCIDevice *s, QEMUFile *f)
 {
     int ret;
-    ret = vmstate_load_state(f, pci_get_vmstate(s), s, s->version_id);
+    ret = vmstate_load_state(f, &vmstate_pci_device, s, s->version_id);
     /* Restore the interrupt status bit. */
     pci_update_irq_status(s);
     return ret;
diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c
index 67fc1e7..adc0c4b 100644
--- a/hw/scsi/megasas.c
+++ b/hw/scsi/megasas.c
@@ -2288,7 +2288,7 @@ static const VMStateDescription vmstate_megasas_gen2 = {
     .minimum_version_id = 0,
     .minimum_version_id_old = 0,
     .fields      = (VMStateField[]) {
-        VMSTATE_PCIE_DEVICE(parent_obj, MegasasState),
+        VMSTATE_PCI_DEVICE(parent_obj, MegasasState),
         VMSTATE_MSIX(parent_obj, MegasasState),
 
         VMSTATE_INT32(fw_state, MegasasState),
diff --git a/hw/scsi/vmw_pvscsi.c b/hw/scsi/vmw_pvscsi.c
index a5ce7de..7557546 100644
--- a/hw/scsi/vmw_pvscsi.c
+++ b/hw/scsi/vmw_pvscsi.c
@@ -1207,7 +1207,7 @@ static const VMStateDescription vmstate_pvscsi_pcie_device = {
     .name = "pvscsi/pcie",
     .needed = pvscsi_vmstate_need_pcie_device,
     .fields = (VMStateField[]) {
-        VMSTATE_PCIE_DEVICE(parent_obj, PVSCSIState),
+        VMSTATE_PCI_DEVICE(parent_obj, PVSCSIState),
         VMSTATE_END_OF_LIST()
     }
 };
diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
index 4acf0c6..e0b5169 100644
--- a/hw/usb/hcd-xhci.c
+++ b/hw/usb/hcd-xhci.c
@@ -3894,7 +3894,7 @@ static const VMStateDescription vmstate_xhci = {
     .version_id = 1,
     .post_load = usb_xhci_post_load,
     .fields = (VMStateField[]) {
-        VMSTATE_PCIE_DEVICE(parent_obj, XHCIState),
+        VMSTATE_PCI_DEVICE(parent_obj, XHCIState),
         VMSTATE_MSIX(parent_obj, XHCIState),
 
         VMSTATE_STRUCT_VARRAY_UINT32(ports, XHCIState, numports, 1,
diff --git a/include/hw/pci/pcie.h b/include/hw/pci/pcie.h
index 056d25e..894262e 100644
--- a/include/hw/pci/pcie.h
+++ b/include/hw/pci/pcie.h
@@ -121,16 +121,6 @@ void pcie_add_capability(PCIDevice *dev,
 void pcie_ari_init(PCIDevice *dev, uint16_t offset, uint16_t nextfn);
 void pcie_dev_ser_num_init(PCIDevice *dev, uint16_t offset, uint64_t ser_num);
 
-extern const VMStateDescription vmstate_pcie_device;
-
-#define VMSTATE_PCIE_DEVICE(_field, _state) {                        \
-    .name       = (stringify(_field)),                               \
-    .size       = sizeof(PCIDevice),                                 \
-    .vmsd       = &vmstate_pcie_device,                              \
-    .flags      = VMS_STRUCT,                                        \
-    .offset     = vmstate_offset_value(_state, _field, PCIDevice),   \
-}
-
 void pcie_cap_slot_hotplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
                               Error **errp);
 void pcie_cap_slot_hot_unplug_request_cb(HotplugHandler *hotplug_dev,
-- 
2.9.3