[SeaBIOS] [PATCH] vcpu hotplug: Setup vcpu add/remove infrastructure, including madt bios_info and dsdt

[Kevin O'Connor]

On Fri, Jan 22, 2010 at 09:35:55AM +0800, Liu, Jinsong wrote:
> From cb997030cba02e7e74a29b3d942aeba9808ed293 Mon Sep 17 00:00:00 2001
> From: Liu, Jinsong <jinsong.liu at intel.com>
> Date: Fri, 22 Jan 2010 03:18:46 +0800
> Subject: [PATCH]         Setup vcpu add/remove infrastructure, including madt bios_info and dsdt.
> 
>         1. setup madt bios_info structure, so that static dsdt get
>            run-time madt info like checksum address, lapic address,
>            max cpu numbers, with least hardcode magic number (realmode
>            address of bios_info).
>         2. setup vcpu add/remove dsdt infrastructure, including processor
>            related acpi objects and control methods. vcpu add/remove will
>            trigger SCI and then control method _L02. By matching madt, vcpu
>            number and add/remove action were found, then by notify control
>            method, it will notify OS acpi driver.
> 
>         Signed-off-by: Liu, Jinsong <jinsong.liu at intel.com>

Thanks.

I'd like to see Gleb's comments on the ACPI changes.

[...]
> diff --git a/src/acpi.c b/src/acpi.c
> index f613b03..037da46 100644
> --- a/src/acpi.c
> +++ b/src/acpi.c
> @@ -344,6 +344,9 @@ build_fadt(int bdf)
>      return fadt;
>  }
> 
> +u32 madt_csum_addr, madt_lapic0_addr;
> +u32 max_cpus_byte, max_cpus_bit;
> +
>  static void*
>  build_madt(void)
>  {
> @@ -360,6 +363,10 @@ build_madt(void)
>      madt->local_apic_address = cpu_to_le32(BUILD_APIC_ADDR);
>      madt->flags = cpu_to_le32(1);
>      struct madt_processor_apic *apic = (void*)&madt[1];
> +    madt_csum_addr = (u32)&madt->checksum;
> +    madt_lapic0_addr = (u32)apic;
> +    max_cpus_byte = MaxCountCPUs / 8;
> +    max_cpus_bit = MaxCountCPUs % 8;

I'm confused at why global variables are being created, exported, and
set, just to be copied to another location later on.

> +/* *****************************************************************
> + * use bios_info to enable dsdt get run-time madt and cpu info,
> + * and to avoid more hardcode magic number.
> + *******************************************************************/
> +#define BIOS_INFO_PHYSICAL_ADDRESS    0x000EA000

That wont work - nothing stops 0xea000 from being used by an option
rom or the bios itself.  If a physical address is needed, the
VAR16FIXED() macro needs to be used.  However, I'm very reluctant to
add new hardcoded addresses - there has to be a very compelling reason
to do that.

-Kevin