Re: [PATCH v22 5/9] ACPI: Record the Generic Error Status Block address

[Peter Maydell <peter.maydell@linaro.org>]

On Wed, 8 Jan 2020 at 11:33, Dongjiu Geng <gengdongjiu@huawei.com> wrote:
>
> Record the GHEB address via fw_cfg file, when recording
> a error to CPER, it will use this address to find out
> Generic Error Data Entries and write the error.
>
> Make the HEST GHES to a GED device.
>
> Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
> Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
> ---
>  hw/acpi/generic_event_device.c         | 15 ++++++++++++++-
>  hw/acpi/ghes.c                         | 16 ++++++++++++++++
>  hw/arm/virt-acpi-build.c               | 13 ++++++++++++-
>  include/hw/acpi/generic_event_device.h |  2 ++
>  include/hw/acpi/ghes.h                 |  6 ++++++
>  5 files changed, 50 insertions(+), 2 deletions(-)
>
> diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c
> index 9cee90c..9bf37e4 100644
> --- a/hw/acpi/generic_event_device.c
> +++ b/hw/acpi/generic_event_device.c
> @@ -234,12 +234,25 @@ static const VMStateDescription vmstate_ged_state = {
>      }
>  };
>
> +static const VMStateDescription vmstate_ghes_state = {
> +    .name = "acpi-ghes-state",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .fields      = (VMStateField[]) {
> +        VMSTATE_UINT64(ghes_addr_le, AcpiGhesState),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
>  static const VMStateDescription vmstate_acpi_ged = {
>      .name = "acpi-ged",
>      .version_id = 1,
>      .minimum_version_id = 1,
>      .fields = (VMStateField[]) {
> -        VMSTATE_STRUCT(ged_state, AcpiGedState, 1, vmstate_ged_state, GEDState),
> +        VMSTATE_STRUCT(ged_state, AcpiGedState, 1,
> +                       vmstate_ged_state, GEDState),
> +        VMSTATE_STRUCT(ghes_state, AcpiGedState, 1,
> +                       vmstate_ghes_state, AcpiGhesState),
>          VMSTATE_END_OF_LIST(),
>      },
>      .subsections = (const VMStateDescription * []) {

You can't just add fields to an existing VMStateDescription
like this -- it will break migration compatibility. Instead you
need to add a new subsection to this vmstate, with a '.needed'
function which indicates when the subsection should be present.

thanks
-- PMM