x86/irq: Add a Kconfig option for posted MSI

This option will be used to support delivering MSIs as posted
interrupts. Interrupt remapping is required.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240423174114.526704-5-jacob.jun.pan@linux.intel.com

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 4474bf32d0a4970daec7fad3f12f8aa4a9e43871..fed22fc662179de9b9ece6da904abf98b67c7950 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -464,6 +464,17 @@ 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_64 && IRQ_REMAP
+       help
+         This enables MSIs that are under interrupt remapping to be delivered as
+         posted interrupts to the host kernel. Interrupt throughput can
+         potentially be improved by coalescing CPU notifications during high
+         frequency bursts.
+
+         If you don't know what to do here, say N.
+
 config X86_MPPARSE
        bool "Enable MPS table" if ACPI
        default y