You have been subscribed to a public bug: 1. In function kvm_write_tsc, when tsc first matched, do kvm->arch.nr_vcpus_matched_tsc++;
2. In function pvclock_update_vm_gtod_copy, if vcpus_matched (also with other conditions meet), ka->use_master_clock will be true; 3. After hot plug vcpu, kvm_arch_vcpu_postcreate and Qemu will call kvm_write_tsc for the new vcpu. Because the tsc will not match, so do kvm->arch.nr_vcpus_matched_tsc = 0; 4. For other already existed vcpu will not call kvm_write_tsc, so will not do kvm->arch.nr_vcpus_matched_tsc++; 5. So vcpus_matched in function pvclock_update_vm_gtod_copy will be false forever, this cause ka->use_master_clock will never be true; ** Affects: linux (Ubuntu) Importance: Undecided Status: New -- Ubuntu 15.10: After hot plug vcpu, kvm_arch->use_master_clock will never be true. https://bugs.launchpad.net/bugs/1567159 You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp