On Thu, Sep 18, 2014 at 06:05:46PM +0200, Paolo Bonzini wrote:
> Besides ACPI tables, there are a few other uses of high memory in SeaBIOS:
> SMBIOS tables and USB drivers use it in particular. These uses allocate
> a very small amount of memory. Malloc metadata also lives there. So we
> need _some_ extra padding there to avoid initrd breakage, but not much.
>
> John Snow found a case where RHEL5 was broken by the recent change to
> ACPI_TABLE_SIZE; in his case 4KB of extra padding are fine, but just
> to be safe I am adding 32KB, which is roughly the same amount of
> padding that was left by QEMU 2.0 and earlier.
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
I already queued a patch with some slightly better comments
so I'll keep that.
Will append your text to the commit log.
Thanks!
> ---
> hw/i386/pc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 77b6782..b9d4be7 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -73,7 +73,7 @@
> #endif
>
> /* Leave a chunk of memory at the top of RAM for the BIOS ACPI tables. */
> -unsigned acpi_data_size = 0x20000;
> +unsigned acpi_data_size = 0x28000;
> void pc_set_legacy_acpi_data_size(void)
> {
> acpi_data_size = 0x10000;
> --
> 1.8.3.1
