On 2015.09.02 at 06:31 +0800, Xiao Guangrong wrote: > > > On 09/01/2015 09:56 PM, Markus Trippelsdorf wrote: > > On 2015.09.01 at 21:00 +0800, Xiao Guangrong wrote: > >> > >> Did it trigger the BUG()/BUG_ON() in mtrr2protval()/fallback_mtrr_type()? > >> If yes, could you please print the actual value out? > > > > It is the BUG() in fallback_mtrr_type(). I changed it to a printk and > > it prints 1 for the value of mtrr. > > > > MTRR_TYPE_WRCOMB 1 > > > > Then I suspect pat is not enabled in your box, could you please check > CONFIG_X86_PAT is selected in your .config file, pat is shown in > /proc/cpuid, "nopat" kernel parameter is used, and dmesg | grep PAT. No. PAT is of course enabled and booting is successful sometimes even with the BUG() in allback_mtrr_type(). I suspect a setup (timing) issue. markus@x4 linux % cat .config | grep X86_PAT CONFIG_X86_PAT=y markus@x4 linux % dmesg | grep PAT [ 0.000000] x86/PAT: Configuration [0-7]: WB WC UC- UC WB WC UC- WT markus@x4 linux % cat /proc/cpuinfo| grep pat flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm 3dnowext 3dnow constant_tsc rep_good nopl nonstop_tsc extd_apicid pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt hw_pstate npt lbrv svm_lock nrip_save vmmcall ... -- Markus -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
