On 27/07/2016 14:39, Igor Mammedov wrote:
> QEMU fails migration with following error:
>
> qemu-system-x86_64: Missing section footer for i2c_bus
> qemu-system-x86_64: load of migration failed: Invalid argument
>
> when migrating from:
> qemu-system-x86_64-v2.6.0 -m 256M rhel72.img -M pc-i440fx-2.6
> to
> qemu-system-x86_64-v2.7.0-rc0 -m 256M rhel72.img -M pc-i440fx-2.6
>
> Regression is added by commit 2293c27f (i2c: implement broadcast write)
>
> Fix it by dropping 'broadcast' VMState introduced by 2293c27f and
> reuse broadcast 0x00 address as broadcast flag in bus->saved_address.
> Then if there were ongoing broadcast at migration time, set
> bus->saved_address to it and at i2c_slave_post_load() time check
> for it instead of transfering and using 'broadcast' VMState.
>
> As result of reusing existing saved_address VMState, no compat
> glue will be needed to keep forward/backward compatiblity. which
> makes fix much less intrusive.
>
> Signed-off-by: Igor Mammedov <imamm...@redhat.com>
> ---
> CC: fred.kon...@greensocs.com
> CC: alistair.fran...@xilinx.com
> CC: crosthwaite.pe...@gmail.com
> CC: hyun.k...@xilinx.com
> CC: peter.mayd...@linaro.org
>
> ---
> hw/i2c/core.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/hw/i2c/core.c b/hw/i2c/core.c
> index abb3efb..4afbe0b 100644
> --- a/hw/i2c/core.c
> +++ b/hw/i2c/core.c
> @@ -17,6 +17,8 @@ struct I2CNode {
> QLIST_ENTRY(I2CNode) next;
> };
>
> +#define I2C_BROADCAST 0x00
> +
> struct I2CBus
> {
> BusState qbus;
> @@ -47,6 +49,8 @@ static void i2c_bus_pre_save(void *opaque)
> if (!QLIST_EMPTY(&bus->current_devs)) {
> if (!bus->broadcast) {
> bus->saved_address =
> QLIST_FIRST(&bus->current_devs)->elt->address;
> + } else {
> + bus->saved_address = I2C_BROADCAST;
> }
> }
> }
> @@ -58,7 +62,6 @@ static const VMStateDescription vmstate_i2c_bus = {
> .pre_save = i2c_bus_pre_save,
> .fields = (VMStateField[]) {
> VMSTATE_UINT8(saved_address, I2CBus),
> - VMSTATE_BOOL(broadcast, I2CBus),
> VMSTATE_END_OF_LIST()
> }
> };
> @@ -93,7 +96,7 @@ int i2c_start_transfer(I2CBus *bus, uint8_t address, int
> recv)
> I2CSlaveClass *sc;
> I2CNode *node;
>
> - if (address == 0x00) {
> + if (address == I2C_BROADCAST) {
> /*
> * This is a broadcast, the current_devs will be all the devices of
> the
> * bus.
> @@ -221,7 +224,8 @@ static int i2c_slave_post_load(void *opaque, int
> version_id)
> I2CNode *node;
>
> bus = I2C_BUS(qdev_get_parent_bus(DEVICE(dev)));
> - if ((bus->saved_address == dev->address) || (bus->broadcast)) {
> + if ((bus->saved_address == dev->address) ||
> + (bus->saved_address == I2C_BROADCAST)) {
> node = g_malloc(sizeof(struct I2CNode));
> node->elt = dev;
> QLIST_INSERT_HEAD(&bus->current_devs, node, next);
>
That's better than both the v1 patch and my suggestion. Good!
I've queued the patch and hope to send a pull request tomorrow.
Paolo
