Re: [PATCH 04/15] x86/irq: Add a Kconfig option for posted MSI

[Robert Hoo]

On 1/27/2024 7:42 AM, Jacob Pan wrote:
> This option will be used to support delivering MSIs as posted
> interrupts. Interrupt remapping is required.
>
> Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
> ---
>   arch/x86/Kconfig | 11 +++++++++++
>   1 file changed, 11 insertions(+)
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 5edec175b9bf..79f04ee2b91c 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -463,6 +463,17 @@ config X86_X2APIC
>   
>   	  If you don't know what to do here, say N.
>   
> +config X86_POSTED_MSI
> +	bool "Enable MSI and MSI-x delivery by posted interrupts"
> +	depends on X86_X2APIC && X86_64 && IRQ_REMAP

Does posted_msi really depend on x2APIC? PID.NDST encoding supports both xAPIC 
and x2APIC.
If posted_msi posts more stringent requirement, I think it deserves an 
explanation in this patch's description.

And, X86_X2APIC already depends on IRQ_REMAP, can we just list one of them here?