qemu supports this enlightenment since version 7.10.
From the qemu commit:
Hyper-V specification allows to pass parameters for certain hypercalls
using XMM registers ("XMM Fast Hypercall Input"). When the feature is
in use, it allows for faster hypercalls processing as KVM can avoid
reading guest's memory.
Signed-off-by: Tim Wiederhake <twiederh@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>