A new ioctl (KVM_CAP_ARM_HW_DIRTY_STATE_TRACK) provides a mechanism for userspace to configure the HDBSS buffer size during live migration, enabling hardware-assisted dirty page tracking. Signed-off-by: eillon Signed-off-by: Tian Zheng --- Documentation/virt/kvm/api.rst | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 57061fa29e6a..25d60ff136e9 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -8703,6 +8703,21 @@ This capability indicate to the userspace whether a PFNMAP memory region can be safely mapped as cacheable. This relies on the presence of force write back (FWB) feature support on the hardware. +7.44 KVM_CAP_ARM_HW_DIRTY_STATE_TRACK +:Architectures: arm64 +:Type: VM +:Parameters: args[0] is the allocation order determining HDBSS buffer size +:Returns: 0 on success, negative value on failure + +Enables hardware-assisted dirty page tracking via the Hardware Dirty State +Tracking Structure (HDBSS). + +When live migration is initiated, userspace can enable this feature by +setting KVM_CAP_ARM_HW_DIRTY_STATE_TRACK through IOCTL. KVM will allocate +per-vCPU HDBSS buffers. + +The feature is disabled by invoking the ioctl again. + 8. Other capabilities. ====================== -- 2.33.0