[lkml]   [2012]   [Jul]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] apic: fix kvm build on UP without IOAPIC
On 07/01/2012 08:05 AM, Michael S. Tsirkin wrote:
> On UP i386, when APIC is disabled
> # CONFIG_X86_UP_APIC is not set
> # CONFIG_PCI_IOAPIC is not set
> code looking at apicdrivers never has any effect but it
> still gets compiled in. In particular, this causes
> build failures with kvm, but it generally bloats the kernel
> unnecessarily.
> Fix by defining both __apicdrivers and __apicdrivers_end
> to be NULL when CONFIG_X86_LOCAL_APIC is unset: I verified
> that as the result any loop scanning __apicdrivers gets optimized out by
> the compiler.
> Warning: a .config with apic disabled doesn't seem to boot
> for me (even without this patch). Still verifying why,
> meanwhile this patch is compile-tested only.
> Signed-off-by: Michael S. Tsirkin <>
> ---
> Note: if this patch makes sense, can x86 maintainers
> please ACK applying it through the kvm tree, since that is
> where we see the issue that it addresses?
> Avi, Marcelo, maybe you can carry this in kvm/linux-next as a temporary
> measure so that linux-next builds?

I'm not happy about that as a workflow, but since you guys have an
immediate problem I guess we can do that.

Acked-by: H. Peter Anvin <>


H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.

 \ /
  Last update: 2012-07-01 19:41    [W:0.080 / U:10.016 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site