* Joerg Roedel <[EMAIL PROTECTED]> wrote:
> > ok. Then i guess we should just leave the warning and the backtrace
> > in place until they get a fix done?
>
> No. I don't agree. The MTRRs are set up by the BIOS because it knows
> the hardware best (I know this is only true in theory). The OS should
> basically trust the BIOS MTRR settings. If the OS can't trust the
> BIOS, like on real hardware, the check and the warning is necessary.
> If the OS can trust the BIOS, like running in a KVM or QEMU virtual
> machine, it should just ignore the case where all MTRRs are blank.
well, i can agree with the warning being pointless on KVM paravirt, but
it's not pointless in the Qemu context.
we fundamentall _dont_ trust the BIOS's MTRR settings, just check the
very function that you modified: mtrr_trim_uncached_memory() - that
function handles _exactly_ a case where a BIOS messes up MTRR's. This
problem has caused real user-side breakage and just not emitting a
warning because Qemu is lazy to emulate a proper PC is not a strong
enough argument.
so i've applied the KVM bits but the warning stays for Qemu.
Ingo
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