Re: [PATCH] x86: trim ram need to check if mtrr is there v2

[Jeremy Fitzhardinge <jeremy@goop.org>]

Yinghai Lu wrote:
> [PATCH] x86: trim ram need to check if mtrr is there v2
>
>   
>>> Jeremy Fitzhardinge wrote:
>>> When booting a current x86.git kernel under kvm, I get this:
>>>
>>> (qemu) Linux version 2.6.24-rc8 (jeremy@ezr) (gcc version 4.1.2 20070925 
>>> (Red Hat 4.1.2-33)) #1928 SMP PREEMPT Thu Jan 24 17:09:04 PST 2008
>>> early_ioremap_init()
>>> BIOS-provided physical RAM map:
>>> BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
>>> BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
>>> BIOS-e820: 00000000000e8000 - 0000000000100000 (reserved)
>>> BIOS-e820: 0000000000100000 - 000000001fff0000 (usable)
>>> BIOS-e820: 000000001fff0000 - 0000000020000000 (ACPI data)
>>> BIOS-e820: 00000000fffc0000 - 0000000100000000 (reserved)
>>> console [earlyser0] enabled
>>> 0MB HIGHMEM available.
>>> 511MB LOWMEM available.
>>> Scan SMP from c0000000 for 1024 bytes.
>>> Scan SMP from c009fc00 for 1024 bytes.
>>> Scan SMP from c00f0000 for 65536 bytes.
>>> Scan SMP from c009fc00 for 1024 bytes.
>>> ***************
>>> **** WARNING: likely BIOS bug
>>> **** MTRRs don't cover all of memory, trimmed 131056 pages
>>> ***************
>>>       
>> H. Peter Anvin wrote:
>> Looks like the code doesn't check that the CPU *has* MTRRs...
>>     
>
> so check it mtrr is there, also check if mem less 4G and is AMD as early
>   

Thanks, this gets me to usermode under kvm.

    J