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[Qemu-devel] [PATCH v4] floppy: save and restore DIR register
From: |
Jason Wang |
Subject: |
[Qemu-devel] [PATCH v4] floppy: save and restore DIR register |
Date: |
Wed, 6 Apr 2011 18:34:31 +0800 |
We need to keep DIR register unchanged across migration, but currently it
depends on the media_changed flags from block layer. Since we do not
save/restore it and the bdrv_open() called in dest node may set the
media_changed flag when trying to open floppy image, guest driver may think the
floppy have changed after migration. To fix this, a new filed media_changed in
FDrive strcutre was introduced in order to save and restore the it from block
layer through pre_save/post_load callbacks.
Signed-off-by: Jason Wang <address@hidden>
---
Changed from V3:
According to Juan's suggestions, back to v2 and just add the checking for
media_changed "changed" in .needed.
Do not fail the migration when src have a drive but dest does not, we can treat
it as user ejected the floppy.
Changed from V2:
According to Paolo's suggestions, a default_migration_media_changed property was
added to avoid saving subsections as much as possible. Its was set media_changed
in pre_load callback and then we can avoid the saving when it was equal to the
media_changed when migrating the FDrive. Behaviors of elder machine types are
also kept through compat_props.
Changed from V1:
Check the drive->bs during post_load.
hw/fdc.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 50 insertions(+), 1 deletions(-)
diff --git a/hw/fdc.c b/hw/fdc.c
index 9fdbc75..edf0360 100644
--- a/hw/fdc.c
+++ b/hw/fdc.c
@@ -36,6 +36,7 @@
#include "qdev-addr.h"
#include "blockdev.h"
#include "sysemu.h"
+#include "block_int.h"
/********************************************************/
/* debug Floppy devices */
@@ -82,6 +83,7 @@ typedef struct FDrive {
uint8_t max_track; /* Nb of tracks */
uint16_t bps; /* Bytes per sector */
uint8_t ro; /* Is read-only */
+ uint8_t media_changed; /* Is media changed */
} FDrive;
static void fd_init(FDrive *drv)
@@ -533,16 +535,63 @@ static CPUWriteMemoryFunc * const
fdctrl_mem_write_strict[3] = {
NULL,
};
+static void fdrive_media_changed_pre_save(void *opaque)
+{
+ FDrive *drive = opaque;
+
+ drive->media_changed = drive->bs->media_changed;
+}
+
+static int fdrive_media_changed_post_load(void *opaque, int version_id)
+{
+ FDrive *drive = opaque;
+
+ if (drive->bs != NULL) {
+ drive->bs->media_changed = drive->media_changed;
+ }
+
+ /* User ejected the floppy when drive->bs == NULL */
+ return 0;
+}
+
+static bool fdrive_media_changed_needed(void *opaque)
+{
+ FDrive *drive = opaque;
+
+ return (drive->bs != NULL && drive->bs->media_changed != 1);
+}
+
+static const VMStateDescription vmstate_fdrive_media_changed = {
+ .name = "fdrive/media_changed",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .minimum_version_id_old = 1,
+ .pre_save = fdrive_media_changed_pre_save,
+ .post_load = fdrive_media_changed_post_load,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT8(media_changed, FDrive),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
static const VMStateDescription vmstate_fdrive = {
.name = "fdrive",
.version_id = 1,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
- .fields = (VMStateField []) {
+ .fields = (VMStateField[]) {
VMSTATE_UINT8(head, FDrive),
VMSTATE_UINT8(track, FDrive),
VMSTATE_UINT8(sect, FDrive),
VMSTATE_END_OF_LIST()
+ },
+ .subsections = (VMStateSubsection[]) {
+ {
+ .vmsd = &vmstate_fdrive_media_changed,
+ .needed = &fdrive_media_changed_needed,
+ } , {
+ /* empty */
+ }
}
};
--
1.7.1
- [Qemu-devel] [PATCH v4] floppy: save and restore DIR register,
Jason Wang <=