Re: 4.8.2 not booting in 32-bit VM without I/O-APIC

From	Borislav Petkov <bp@alien8.de>
Newsgroups	linux.kernel
Subject	Re: 4.8.2 not booting in 32-bit VM without I/O-APIC
Date	2016-10-29 12:20 +0200
Message-ID	<sxyU2-4R3-5@gated-at.bofh.it> (permalink)
References	<sxkxH-3Bi-1@gated-at.bofh.it> <sxkHn-3Tx-1@gated-at.bofh.it> <sxlaq-43e-21@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Fri, Oct 28, 2016 at 09:34:53PM +0200, Thomas Gleixner wrote:
> Right. That mapping setup is an utter trainwreck as we do it from multiple
> places, but there is no reason why we can't move it before the call to
> prefill_possible_map().

> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index bbfbca5fea0c..b59fdba3cbdf 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -1221,11 +1221,13 @@ void __init setup_arch(char **cmdline_p)
>  	 */
>  	get_smp_config();
>  
> +	/* Make sure apic is mapped before prefill_possible_map() */
> +	init_apic_mappings();
> +
>  	prefill_possible_map();
>  
>  	init_cpu_to_node();
>  
> -	init_apic_mappings();
>  	io_apic_init_mappings();
>  
>  	kvm_guest_init();

FWIW, I got another user's confirmation that this works with his
virtual box:

https://bugzilla.suse.com/show_bug.cgi?id=1006417#c32
https://bugzilla.suse.com/show_bug.cgi?id=1006417#c33

Thanks.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.

Thread

Re: 4.8.2 not booting in 32-bit VM without I/O-APIC Michal Necasek <michal.necasek@oracle.com> - 2016-10-28 21:00 +0200
  Re: 4.8.2 not booting in 32-bit VM without I/O-APIC Thomas Gleixner <tglx@linutronix.de> - 2016-10-28 21:10 +0200
    Re: 4.8.2 not booting in 32-bit VM without I/O-APIC Thomas Gleixner <tglx@linutronix.de> - 2016-10-28 21:40 +0200
      Re: 4.8.2 not booting in 32-bit VM without I/O-APIC Borislav Petkov <bp@alien8.de> - 2016-10-29 12:20 +0200
      [tip:x86/urgent] x86/smpboot: Init apic mapping before usage tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-10-29 14:10 +0200
      [tip:x86/urgent] x86/smpboot: Init apic mapping before usage tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-10-29 14:10 +0200

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