On 2017-11-17 01:50, Paolo Bonzini wrote:
On 16/11/2017 15:28, Quan Xu wrote:vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);+ kvm_load_guest_fpu(vcpu);+ for (;;) { if (kvm_vcpu_running(vcpu)) { r = vcpu_enter_guest(vcpu); << as Rik dropped kvm_load_guest_fpu(vcpu) in vcpu_enter_guest() .. in case still in kvm mode, how to make sure to pkru is always the right one before enter guest mode, not be preempted before preempt_disable() after migration? :(As you know: 1) kvm_load_guest_fpu doesn't load the guest PKRU, it keeps the userspace PKRU. 2) the guest PKRU is only ever set in a preemption-disabled area Thus, context switch always sees the userspace PKRU. The guest PKRU is only set the next time vmx_vcpu_run executes. Paolo
Paolo, thanks for your explanation!!:-) Rik, could you cc me in v2? Quan
