On 06/07/2016 08:05, Haozhong Zhang wrote: >> > >> > Nested preemption timer is emulated by hrtimer, so it doesn't >> > influence vmcs02, why this is needed? > Nested (L2) preemption timer is not affected for sure, and this patch > is to fix another problem caused by using L1 preemption timer for L1 > TSC deadline timer. When we use L1 VMX preemption timer for L1 TSC > deadline timer, we intend to use the pin-based exec config and the VMX > preemption timer value in vmcs01. However, when L2 guest is running, > vmcs02 is loaded as the current VMCS so that a different VMX > preemption timer config is used (i.e. VMX preemption timer is disabled > in prepare_vmcs02()). If we still use preemption timer for L1 TSC > deadline timer at this moment, then L1 TSC deadline timer will not be > able to be triggered when L2 guest is running. The right fix then is to set the pin-based controls in prepare_vmcs02, based on vcpu->arch.hv_deadline_tsc. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
