On 2017-10-18 at 17:13:18 +0300, Mihai Donțu wrote: > On Wed, 2017-10-18 at 11:35 +0200, Paolo Bonzini wrote: > > On 16/10/2017 02:08, Yi Zhang wrote: > > > > And the introspection facility by Mihai uses a completely > > > > different API for the introspector, based on sockets rather than ioctls. > > > > So I'm not sure this is the right API at all. > > > > > > Currently, We only block the write access, As far as I know an example, > > > we now using it in a security daemon: > > > > Understood. However, I think QEMU is the wrong place to set this up. > > > > If the kernel wants to protect _itself_, it should use a hypercall. If > > an introspector appliance wants to protect the guest kernel, it should > > use the socket that connects it to the hypervisor. > > We have been looking at using SPP for VMI for quite some time. If a > guest kernel will be able to control it (can it do so with EPT?) then > it would be useful a simple switch that disables this ability, as an > introspector wouldn't want the guest is trying to protect to interfere > with it. Could you mind to provide more information and history about your investigation? > > Also, if Intel doesn't have a specific use case for it that requires > separate access to SPP control, then maybe we can fold it into the VMI > API we are working on? That's totally Excellent as we really don't have a specific user case at this time. BTW, I have already submit the SPP implementation draft in Xen side. when you got some time, you can take a look at if that match your requirement. > > Thanks, > > > > Consider It has a server which launching in the host user-space, and a > > > client launching in the guest kernel. Yes, they are communicate with > > > sockets. The guest kernel wanna protect a special area to prevent all > > > the process including the kernel itself modify this area. the client > > > could send the guest physical address via the security socket to server > > > side, and server would update these protection into KVM. Thus, all the > > > write access in a guest specific area will be blocked. > > > > > > Now the implementation only on the second half(maybe third ^_^) of this > > > example: 'How kvm set the write-protect into a specific GFN?' > > > > > > Maybe a user space tools which use ioctl let kvm mmu update the > > > write-protection is a better choice. > > -- > Mihai Donțu >
