I need to define a new exit reason of my own and want to set the exit reason in VMCS before switching to the host KVM module,then do something in KVM hypervisor for this reason.But I notice the vmcs_writel() is static,how can I do it?
You can't define new exit reasons per se, but you can use a vmcall instruction to cause a vmexit from a guest. You can establish some form of calling convention around the vmexit that you can then setup in the host context and decode in the hypervisor context to indicate your 'reason'. I've never read KVM source, but I suspect you will find it already has such a protocol established around 'vmexit'.
vm is excellent tool to work with a different platform in a single window