Most windows guests which I have on hand currently still utilize APIC Timer periodic/oneshot mode instead of APIC Timer tsc-deadline mode: - windows 2008 server r2 - windows 2012 server r2 - windows 7 - windows 10
This patchset adds the support using the VMX preemption timer for APIC Timer periodic/oneshot mode. I add a print in oneshot mode testcase of kvm-unit-tests/apic.flat and observed that w/ patch the latency is ~2% of w/o patch. I think maybe something is still not right in the patchset, in addition, tmcct in apic_get_tmcct() maybe is not calculated correctly. Your comments to improve the patchset is a great appreciated. Wanpeng Li (2): KVM: lapic: Extract start_sw_period() to handle oneshot/periodic mode KVM: x86: Support using the vmx preemption timer for APIC Timer periodic/one mode arch/x86/kvm/lapic.c | 162 ++++++++++++++++++++++++++++++--------------------- 1 file changed, 95 insertions(+), 67 deletions(-) -- 1.9.1
