> Could it be that your field is placed after the end of the page? > > Paolo My code works well as expected when I move the added field to the top of kvm_run structure. I did some investigation to understand why my code does not work when I put the added field at the end of kvm_run. Here is what I got: KVM: @vcpu->run -> 0x*****e000 size of (struct kvm_run) -> 1360 added field offset in kvm_run -> 1336 Qemu: @cpu->kvm_run -> 0x****f000 size of (struct kvm_run) -> 2384 added field offset in kvm_run -> 2360 I see that in Qemu and KVM the added field is inside the page but at different offset from the start of kvm_run. Do you think that the problem is that the added field is at different offsets in KVM & Qemu ? Yacine
