[Qemu-devel] [PATCH 2/4] Disable section footers on older machine types

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

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

The next patch adds section footers; but we don't want to
break migration compatibility so disable them on older
machine types

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 hw/i386/pc_piix.c             | 2 ++
 hw/i386/pc_q35.c              | 2 ++
 include/migration/migration.h | 1 +
 savevm.c                      | 7 +++++++
 4 files changed, 12 insertions(+)

diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 212e263..dd4c826 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -52,6 +52,7 @@
 #ifdef CONFIG_XEN
 #  include <xen/hvm/hvm_info_table.h>
 #endif
+#include "migration/migration.h"
 
 #define MAX_IDE_BUS 2
 
@@ -312,6 +313,7 @@ static void pc_init_pci(MachineState *machine)
 
 static void pc_compat_2_3(MachineState *machine)
 {
+    savevm_skip_section_footers();
 }
 
 static void pc_compat_2_2(MachineState *machine)
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index e67f2de..3fea169 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -45,6 +45,7 @@
 #include "hw/usb.h"
 #include "hw/cpu/icc_bus.h"
 #include "qemu/error-report.h"
+#include "migration/migration.h"
 
 /* ICH9 AHCI has 6 ports */
 #define MAX_SATA_PORTS     6
@@ -291,6 +292,7 @@ static void pc_q35_init(MachineState *machine)
 
 static void pc_compat_2_3(MachineState *machine)
 {
+    savevm_skip_section_footers();
 }
 
 static void pc_compat_2_2(MachineState *machine)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index a6e025a..9afee02 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -180,4 +180,5 @@ size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
                              ram_addr_t offset, size_t size,
                              uint64_t *bytes_sent);
 
+void savevm_skip_section_footers(void);
 #endif
diff --git a/savevm.c b/savevm.c
index edb8f33..415914f 100644
--- a/savevm.c
+++ b/savevm.c
@@ -51,6 +51,8 @@
 #define ARP_PTYPE_IP 0x0800
 #define ARP_OP_REQUEST_REV 0x3
 
+static bool skip_section_footers;
+
 static int announce_self_create(uint8_t *buf,
                                 uint8_t *mac_addr)
 {
@@ -602,6 +604,11 @@ static void vmstate_save(QEMUFile *f, SaveStateEntry *se, QJSON *vmdesc)
     vmstate_save_state(f, se->vmsd, se->opaque, vmdesc);
 }
 
+void savevm_skip_section_footers(void)
+{
+    skip_section_footers = true;
+}
+
 /*
  * Write the header for device section (QEMU_VM_SECTION START/END/PART/FULL)
  */
-- 
2.4.1