hw/arm/virt: Disable pl011 clock migration if needed

A clock is added by commit aac63e0e6e ("hw/char/pl011: add a clock
input") since v5.2.0 which corresponds to virt-5.2 machine type. It
causes backwards migration failure from upstream to downstream (v5.1.0)
when the machine type is specified with virt-5.1.

This fixes the issue by following instructions from section "Connecting
subsections to properties" in docs/devel/migration.rst. With this applied,
the PL011 clock is migrated based on the machine type.

   virt-5.2 or newer:  migration
   virt-5.1 or older:  non-migration

Cc: qemu-stable@nongnu.org # v5.2.0+
Fixes: aac63e0e6e ("hw/char/pl011: add a clock input")
Suggested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Message-id: 20210318023801.18287-1-gshan@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Gavin Shan 2021-03-18 10:38:01 +08:00 committed by Peter Maydell
parent 5ca634afcf
commit e6fa978d83
3 changed files with 11 additions and 0 deletions

View File

@ -322,10 +322,18 @@ static const MemoryRegionOps pl011_ops = {
.endianness = DEVICE_NATIVE_ENDIAN,
};
static bool pl011_clock_needed(void *opaque)
{
PL011State *s = PL011(opaque);
return s->migrate_clk;
}
static const VMStateDescription vmstate_pl011_clock = {
.name = "pl011/clock",
.version_id = 1,
.minimum_version_id = 1,
.needed = pl011_clock_needed,
.fields = (VMStateField[]) {
VMSTATE_CLOCK(clk, PL011State),
VMSTATE_END_OF_LIST()
@ -363,6 +371,7 @@ static const VMStateDescription vmstate_pl011 = {
static Property pl011_properties[] = {
DEFINE_PROP_CHR("chardev", PL011State, chr),
DEFINE_PROP_BOOL("migrate-clk", PL011State, migrate_clk, true),
DEFINE_PROP_END_OF_LIST(),
};

View File

@ -52,6 +52,7 @@ GlobalProperty hw_compat_5_1[] = {
{ "virtio-scsi-device", "num_queues", "1"},
{ "nvme", "use-intel-id", "on"},
{ "pvpanic", "events", "1"}, /* PVPANIC_PANICKED */
{ "pl011", "migrate-clk", "off" },
};
const size_t hw_compat_5_1_len = G_N_ELEMENTS(hw_compat_5_1);

View File

@ -50,6 +50,7 @@ struct PL011State {
CharBackend chr;
qemu_irq irq[6];
Clock *clk;
bool migrate_clk;
const unsigned char *id;
};