Re: [Qemu-devel] [PATCH v4 2/3] pc: acpi-build: update linker on guest access

[Marcel Apfelbaum <marcel@redhat.com>]

On 02/09/2015 03:59 PM, Igor Mammedov wrote:
> Linker table is build only once, so if later during
> tables rebuild sizes of other ACPI tables change
> pointers will be patched incorrectly due to wrong
> offsets in linker. Resulting in guest not being able
> to find ACPI tables.
> Fix it by updating 'linker' table with the rest of
> tables when firmware reads it.
>
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
>   hw/i386/acpi-build.c | 8 +++++++-
>   1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index 5b2b017..21ea3db 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -1527,6 +1527,8 @@ struct AcpiBuildState {
>       uint8_t patched;
>       PcGuestInfo *guest_info;
>       void *rsdp;
> +    ram_addr_t linker_ram;
> +    uint32_t linker_size;
>   } AcpiBuildState;
>
>   static bool acpi_get_mcfg(AcpiMcfgInfo *mcfg)
> @@ -1733,6 +1735,8 @@ static void acpi_build_update(void *build_opaque, uint32_t offset)
>       memcpy(qemu_get_ram_ptr(build_state->table_ram), tables.table_data->data,
>              build_state->table_size);
>       memcpy(build_state->rsdp, tables.rsdp->data, acpi_data_len(tables.rsdp));
> +    memcpy(qemu_get_ram_ptr(build_state->linker_ram), tables.linker->data,
> +           build_state->linker_size);
>
>       cpu_physical_memory_set_dirty_range_nocode(build_state->table_ram,
>                                                  build_state->table_size);
> @@ -1799,7 +1803,9 @@ void acpi_setup(PcGuestInfo *guest_info)
>       assert(build_state->table_ram != RAM_ADDR_MAX);
>       build_state->table_size = acpi_data_len(tables.table_data);
>
> -    acpi_add_rom_blob(NULL, tables.linker, "etc/table-loader", 0);
> +    build_state->linker_ram =
> +        acpi_add_rom_blob(build_state, tables.linker, "etc/table-loader", 0);
> +    build_state->linker_size = acpi_data_len(tables.linker);
>
>       fw_cfg_add_file(guest_info->fw_cfg, ACPI_BUILD_TPMLOG_FILE,
>                       tables.tcpalog->data, acpi_data_len(tables.tcpalog));
>


Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>