On Jan 24, 2008 11:43 PM, Jeremy Fitzhardinge <[EMAIL PROTECTED]> wrote: > > 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 ([EMAIL PROTECTED]) (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.
i think the is 0xffffffff to 0xffffffffUL make the difference. the cpu mode in KVM/qemu may cpu_has_mtrr, but doesn't really have return mtrr msr with correct value. is_cpu(INTEL) already make sure we have mtrr_if got assigned and cpu_has_mtrr. may need to fix qemu instead... Can you try post /proc/mtrr for your guest in kvm/qemu? Thanks YH -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/