From 93b71801a8274cd9511557faf04365a5de487197 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 22 Feb 2022 09:06:54 -0500 Subject: KVM: PPC: reserve capability 210 for KVM_CAP_PPC_AIL_MODE_3 Add KVM_CAP_PPC_AIL_MODE_3 to advertise the capability to set the AIL resource mode to 3 with the H_SET_MODE hypercall. This capability differs between processor types and KVM types (PR, HV, Nested HV), and affects guest-visible behaviour. QEMU will implement a cap-ail-mode-3 to control this behaviour[1], and use the KVM CAP if available to determine KVM support[2]. Reviewed-by: Fabiano Rosas Signed-off-by: Nicholas Piggin Signed-off-by: Paolo Bonzini --- Documentation/virt/kvm/api.rst | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'Documentation/virt') diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index a4267104db50..9954568c7eab 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6997,6 +6997,20 @@ indicated by the fd to the VM this is called on. This is intended to support intra-host migration of VMs between userspace VMMs, upgrading the VMM process without interrupting the guest. +7.30 KVM_CAP_PPC_AIL_MODE_3 +------------------------------- + +:Capability: KVM_CAP_PPC_AIL_MODE_3 +:Architectures: ppc +:Type: vm + +This capability indicates that the kernel supports the mode 3 setting for the +"Address Translation Mode on Interrupt" aka "Alternate Interrupt Location" +resource that is controlled with the H_SET_MODE hypercall. + +This capability allows a guest kernel to use a better-performance mode for +handling interrupts and system calls. + 8. Other capabilities. ====================== -- cgit v1.2.3