Re: [PATCH v5 17/23] hw/i386/pc: Remove PCMachineClass::resizable_acpi_blob

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 29 May 2024 07:15:33 +0200
Philippe Mathieu-Daudé <philmd@linaro.org> wrote:

> PCMachineClass::resizable_acpi_blob was only used by the
> pc-i440fx-2.2 machine, which got removed. It is now always
> true. Remove it, simplifying acpi_build().
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> Reviewed-by: Zhao Liu <zhao1.liu@intel.com>

Reviewed-by: Igor Mammedov <imammedo@redhat.com>

> ---
>  include/hw/i386/pc.h |  3 ---
>  hw/i386/acpi-build.c | 10 ----------
>  hw/i386/pc.c         |  1 -
>  3 files changed, 14 deletions(-)
> 
> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> index 996495985e..808de4eca7 100644
> --- a/include/hw/i386/pc.h
> +++ b/include/hw/i386/pc.h
> @@ -125,9 +125,6 @@ struct PCMachineClass {
>      /* create kvmclock device even when KVM PV features are not exposed */
>      bool kvmclock_create_always;
>  
> -    /* resizable acpi blob compat */
> -    bool resizable_acpi_blob;
> -
>      /*
>       * whether the machine type implements broken 32-bit address space bound
>       * check for memory.
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index a6f8203460..ab2d4d8dcb 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -2688,16 +2688,6 @@ void acpi_build(AcpiBuildTables *tables, MachineState *machine)
>       * keep the table size stable for all (max_cpus, max_memory_slots)
>       * combinations.
>       */
> -    /* Make sure we have a buffer in case we need to resize the tables. */
> -    if ((tables_blob->len > ACPI_BUILD_TABLE_SIZE / 2) &&
> -        !pcmc->resizable_acpi_blob) {
> -        /* As of QEMU 2.1, this fires with 160 VCPUs and 255 memory slots.  */
> -        warn_report("ACPI table size %u exceeds %d bytes,"
> -                    " migration may not work",
> -                    tables_blob->len, ACPI_BUILD_TABLE_SIZE / 2);
> -        error_printf("Try removing CPUs, NUMA nodes, memory slots"
> -                     " or PCI bridges.\n");
> -    }
>      acpi_align_size(tables_blob, ACPI_BUILD_TABLE_SIZE);
>  
>      acpi_align_size(tables->linker->cmd_blob, ACPI_BUILD_ALIGN_SIZE);
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index ccfcb92605..fae21f75aa 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -1768,7 +1768,6 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
>      pcmc->acpi_data_size = 0x20000 + 0x8000;
>      pcmc->pvh_enabled = true;
>      pcmc->kvmclock_create_always = true;
> -    pcmc->resizable_acpi_blob = true;
>      x86mc->apic_xrupt_override = true;
>      assert(!mc->get_hotplug_handler);
>      mc->get_hotplug_handler = pc_get_hotplug_handler;