From f73f8173126ba68eb1c42bd9a234a51d78576ca6 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Fri, 18 Sep 2015 22:29:39 +0800 Subject: virt: IRQ bypass manager When a physical I/O device is assigned to a virtual machine through facilities like VFIO and KVM, the interrupt for the device generally bounces through the host system before being injected into the VM. However, hardware technologies exist that often allow the host to be bypassed for some of these scenarios. Intel Posted Interrupts allow the specified physical edge interrupts to be directly injected into a guest when delivered to a physical processor while the vCPU is running. ARM IRQ Forwarding allows forwarded physical interrupts to be directly deactivated by the guest. The IRQ bypass manager here is meant to provide the shim to connect interrupt producers, generally the host physical device driver, with interrupt consumers, generally the hypervisor, in order to configure these bypass mechanism. To do this, we base the connection on a shared, opaque token. For KVM-VFIO this is expected to be an eventfd_ctx since this is the connection we already use to connect an eventfd to an irqfd on the in-kernel path. When a producer and consumer with matching tokens is found, callbacks via both registered participants allow the bypass facilities to be automatically enabled. Signed-off-by: Alex Williamson Reviewed-by: Eric Auger Tested-by: Eric Auger Tested-by: Feng Wu Signed-off-by: Feng Wu Signed-off-by: Paolo Bonzini --- virt/lib/Kconfig | 2 ++ 1 file changed, 2 insertions(+) create mode 100644 virt/lib/Kconfig (limited to 'virt/lib/Kconfig') diff --git a/virt/lib/Kconfig b/virt/lib/Kconfig new file mode 100644 index 000000000000..89a414f815d2 --- /dev/null +++ b/virt/lib/Kconfig @@ -0,0 +1,2 @@ +config IRQ_BYPASS_MANAGER + tristate -- cgit v1.2.3