[PATCH 2/2] xen: cleanup unrealized flash devices

[Paul Durrant <paul@xen.org>]

From: Paul Durrant <pdurrant@amazon.com>

The generic pc_machine_initfn() calls pc_system_flash_create() which creates
'system.flash0' and 'system.flash1' devices. These devices are then realized
by pc_system_flash_map() which is called from pc_system_firmware_init() which
itself is called via pc_memory_init(). The latter however is not called when
xen_enable() is true and hence the following assertion fails:

qemu-system-i386: hw/core/qdev.c:439: qdev_assert_realized_properly:
Assertion `dev->realized' failed

These flash devices are unneeded when using Xen so this patch avoids the
assertion by simply removing them using pc_system_flash_cleanup_unused().

Reported-by: Jason Andryuk <jandryuk@gmail.com>
Fixes: ebc29e1beab0 ("pc: Support firmware configuration with -blockdev")
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Tested-by: Jason Andryuk <jandryuk@gmail.com>
---
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
---
 hw/i386/pc_piix.c    | 9 ++++++---
 hw/i386/pc_sysfw.c   | 2 +-
 include/hw/i386/pc.h | 1 +
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 1497d0e4ae..977d40afb8 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -186,9 +186,12 @@ static void pc_init1(MachineState *machine,
     if (!xen_enabled()) {
         pc_memory_init(pcms, system_memory,
                        rom_memory, &ram_memory);
-    } else if (machine->kernel_filename != NULL) {
-        /* For xen HVM direct kernel boot, load linux here */
-        xen_load_linux(pcms);
+    } else {
+        pc_system_flash_cleanup_unused(pcms);
+        if (machine->kernel_filename != NULL) {
+            /* For xen HVM direct kernel boot, load linux here */
+            xen_load_linux(pcms);
+        }
     }
 
     gsi_state = pc_gsi_create(&x86ms->gsi, pcmc->pci_enabled);
diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c
index ec2a3b3e7e..0ff47a4b59 100644
--- a/hw/i386/pc_sysfw.c
+++ b/hw/i386/pc_sysfw.c
@@ -108,7 +108,7 @@ void pc_system_flash_create(PCMachineState *pcms)
     }
 }
 
-static void pc_system_flash_cleanup_unused(PCMachineState *pcms)
+void pc_system_flash_cleanup_unused(PCMachineState *pcms)
 {
     char *prop_name;
     int i;
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index e6135c34d6..497f2b7ab7 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -187,6 +187,7 @@ int cmos_get_fd_drive_type(FloppyDriveType fd0);
 
 /* pc_sysfw.c */
 void pc_system_flash_create(PCMachineState *pcms);
+void pc_system_flash_cleanup_unused(PCMachineState *pcms);
 void pc_system_firmware_init(PCMachineState *pcms, MemoryRegion *rom_memory);
 
 /* acpi-build.c */
-- 
2.20.1