On 03/10/2017 14:59, HEBBAL Yacine wrote: > Hi All, > I added a field to "kvm_run" data structure in both Qemu and KVM to > create a communication interface for a VM security monitoring > application (in user space) in order to avoid heavy modifications in > the hypervisor. > The problem I'm facing is that when this field is updated in KVM after > a VM exit, I don't see the written value in "kvm_run" at Qemu function > "kvm_arch_handle_exit". > My question is how "kvm_run" is synchronized between Qemu and KVM ? > Thank you in advance for your answers. There is no need for synchronization. kvm_run maps to exactly the same pages in QEMU and KVM. See Linux commit 460df4c1fc7c00829050c08d6368dc6e6beef307 for an example of adding a field to struct kvm_run. Paolo
