Re: [PATCH RESEND 1/1] X86: Handle Hyper-V vmbus interrupts as special hypervisor interrupts

[Borislav Petkov <bp@alien8.de>]

On Wed, Jan 23, 2013 at 05:56:09PM -0800, K. Y. Srinivasan wrote:
> diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
> index 1975122..803ca69 100644
> --- a/arch/x86/kernel/entry_64.S
> +++ b/arch/x86/kernel/entry_64.S
> @@ -1446,11 +1446,16 @@ ENTRY(xen_failsafe_callback)
>  	CFI_ENDPROC
>  END(xen_failsafe_callback)
>  
> -apicinterrupt XEN_HVM_EVTCHN_CALLBACK \
> +apicinterrupt HYPERVISOR_CALLBACK_VECTOR \
>  	xen_hvm_callback_vector xen_evtchn_do_upcall
>  
>  #endif /* CONFIG_XEN */
>  
> +#if IS_ENABLED(CONFIG_HYPERV)
> +apicinterrupt HYPERVISOR_CALLBACK_VECTOR \
> +	hyperv_callback_vector hyperv_vector_handler
> +#endif /* CONFIG_HYPERV */

arch/x86/built-in.o: In function `_set_gate':
/w/kernel/linux-2.6/arch/x86/include/asm/desc.h:328: undefined reference to `hyperv_callback_vector'
make: *** [vmlinux] Error 1

because, of course:

# CONFIG_HYPERV is not set

But, I have a more serious pet-peeve with the whole hypervisors
detection stuff: we're building arch/x86/kernel/cpu/hypervisor.c
unconditionally and yet, we have CONFIG_PARAVIRT_GUEST to ask the user
whether she wants to enable some options for running linux as a guest.

And actually, it would be better to put all that virt-related stuff
under a config option called HYPERVISOR or whatever, under "Processor
type and features" which opens a menu with all virt stuff for people and
distros to select.

This way, init_hypervisor_platform and the rest of hypervisors stuff
won't run needlessly on baremetal and setups who don't want that.

Any non-starter reasons for not doing that?

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
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