2016-09-20 21:06 GMT+08:00 Radim Krčmář <rkrcmar@xxxxxxxxxx>: > 2016-09-20 08:35+0800, Wanpeng Li: >> From: Wanpeng Li <wanpeng.li@xxxxxxxxxxx> >> >> I observed that kvmvapic(to optimize flexpriority=N or AMD) is used >> to boost TPR access when testing kvm-unit-test/eventinj.flat tpr case >> on my haswell desktop (w/ flexpriority, w/o APICv). Commit (8d14695f9542 >> x86, apicv: add virtual x2apic support) disable virtual x2apic mode >> completely if w/o APICv, and the author also told me that windows guest >> can't enter into x2apic mode when he developed the APICv feature several >> years ago. However, it is not truth currently, Interrupt Remapping and >> vIOMMU is added to qemu and the developers from Intel test windows 8 can >> work in x2apic mode w/ Interrupt Remapping enabled recently. >> >> This patch enables TPR shadow for virtual x2apic mode to boost >> windows guest in x2apic mode even if w/o APICv. >> >> Can pass the kvm-unit-test. >> >> Suggested-by: Wincy Van <fanwenyi0529@xxxxxxxxx> >> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> >> Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx> >> Cc: Wincy Van <fanwenyi0529@xxxxxxxxx> >> Cc: Yang Zhang <yang.zhang.wz@xxxxxxxxx> >> Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx> >> --- >> v1 -> v2: >> * leverage the cached msr bitmap > > V2 has a similar bug as V1 ... we have to intercept most MSRs when the > APICv is disabled for selected VCPU, but globally enabled. > > We need at least 2 sets of bitmaps for x2apic: one for > "enable_apicv && kvm_vcpu_apicv_active()" > > the other for > "enable_apicv && !kvm_vcpu_apicv_active()" > and "!enable_apicv" > > and use the correct one in vmx_set_msr_bitmap(). Agreed, please review v3. :) Regards, Wanpeng Li -- 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
