Messages in this thread | | | Date | Mon, 22 Aug 2022 10:32:28 +0200 | Subject | Re: [PATCH v2 01/10] x86/mtrr: fix MTRR fixup on APs | From | Juergen Gross <> |
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On 22.08.22 10:28, Borislav Petkov wrote: > On Mon, Aug 22, 2022 at 07:17:40AM +0200, Juergen Gross wrote: >> And then there is mtrr_state_warn() in arch/x86/kernel/cpu/mtrr/generic.c >> which has a comment saying: >> >> /* Some BIOS's are messed up and don't set all MTRRs the same! */ > > That thing also says: > > pr_info("mtrr: probably your BIOS does not setup all CPUs.\n"); > pr_info("mtrr: corrected configuration.\n"); > > because it'll go and force on all CPUs the MTRR state it read from the > BSP in mtrr_bp_init->get_mtrr_state. > >> Yes, the chances are slim to hit such a box, > > Well, my workstation says: > > $ dmesg | grep -i mtrr > [ 0.391514] mtrr: your CPUs had inconsistent variable MTRR settings > [ 0.395199] mtrr: probably your BIOS does not setup all CPUs. > [ 0.399199] mtrr: corrected configuration. > > but that's the variable MTRRs. > >> but your reasoning suggests I should remove the related code? > > My reasoning says you should not do anything at all here - works as > advertized. :-) >
And what about the:
pr_warn("mtrr: your CPUs had inconsistent MTRRdefType settings\n");
This is the case the patch would fix.
Juergen [unhandled content-type:application/pgp-keys][unhandled content-type:application/pgp-signature] | |