xemu/hw/core
Peter Maydell 032cfe6a79 pl031: Correctly migrate state when using -rtc clock=host
The PL031 RTC tracks the difference between the guest RTC
and the host RTC using a tick_offset field. For migration,
however, we currently always migrate the offset between
the guest and the vm_clock, even if the RTC clock is not
the same as the vm_clock; this was an attempt to retain
migration backwards compatibility.

Unfortunately this results in the RTC behaving oddly across
a VM state save and restore -- since the VM clock stands still
across save-then-restore, regardless of how much real world
time has elapsed, the guest RTC ends up out of sync with the
host RTC in the restored VM.

Fix this by migrating the raw tick_offset. To retain migration
compatibility as far as possible, we have a new property
migrate-tick-offset; by default this is 'true' and we will
migrate the true tick offset in a new subsection; if the
incoming data has no subsection we fall back to the old
vm_clock-based offset information, so old->new migration
compatibility is preserved. For complete new->old migration
compatibility, the property is set to 'false' for 4.0 and
earlier machine types (this will only affect 'virt-4.0'
and below, as none of the other pl031-using machines are
versioned).

Reported-by: Russell King <rmk@armlinux.org.uk>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: 20190709143912.28905-1-peter.maydell@linaro.org
2019-07-15 14:17:04 +01:00
..
bus.c hw/core/bus.c: Only the main system bus can have no parent 2019-06-13 15:14:03 +01:00
empty_slot.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
fw-path-provider.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
generic-loader.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
hotplug.c call HotplugHandler->plug() as the last step in device realization 2018-10-19 13:44:12 +02:00
irq.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
Kconfig kconfig: introduce kconfig files 2019-03-07 21:45:53 +01:00
loader-fit.c loader-fit: Wean off error_printf() 2019-04-17 21:21:49 +02:00
loader.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
machine-hmp-cmds.c i386/cpu: Consolidate die-id validity in smp context 2019-07-05 17:08:03 -03:00
machine-qmp-cmds.c qmp: Add deprecation information to query-machines 2019-07-05 17:08:04 -03:00
machine.c pl031: Correctly migrate state when using -rtc clock=host 2019-07-15 14:17:04 +01:00
Makefile.objs qdev: add qdev_add_vm_change_state_handler() 2019-07-08 16:00:26 +02:00
nmi.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
null-machine.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
numa.c numa: allow memory-less nodes when using memdev as backend 2019-07-05 17:12:45 -03:00
or-irq.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
platform-bus.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
ptimer.c ptimer: Add TRIGGER_ONLY_ON_DECREMENT policy option 2018-07-09 14:51:34 +01:00
qdev-fw.c linux-user: remove nmi.c and fw-path-provider.c 2018-01-23 14:20:52 +01:00
qdev-properties-system.c block: Add qdev_prop_drive_iothread property type 2019-06-04 15:22:22 +02:00
qdev-properties.c qemu-common: Move qemu_isalnum() etc. to qemu/ctype.h 2019-06-11 20:22:09 +02:00
qdev.c qapi: Split qom.json and qdev.json off misc.json 2019-07-02 07:19:57 +02:00
register.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
reset.c qemu/queue.h: leave head structs anonymous unless necessary 2019-01-11 15:46:55 +01:00
split-irq.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
stream.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
sysbus.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
uboot_image.h Support u-boot noload images for arm as used by, NetBSD/evbarm GENERIC kernel. 2019-01-07 15:46:20 +00:00
vm-change-state-handler.c qdev: add qdev_add_vm_change_state_handler() 2019-07-08 16:00:26 +02:00