Re: [PATCH v5 5/5] KVM: x86: hyperv: implement PV IPI send hypercalls

2018-08-28 Thread Roman Kagan
On Mon, Aug 27, 2018 at 06:48:58PM +0200, Vitaly Kuznetsov wrote: > Using hypercall for sending IPIs is faster because this allows to specify > any number of vCPUs (even > 64 with sparse CPU set), the whole procedure > will take only one VMEXIT. > > Current Hyper-V TLFS (v5.0b) claims that

Re: [PATCH v5 5/5] KVM: x86: hyperv: implement PV IPI send hypercalls

2018-08-28 Thread Roman Kagan
On Mon, Aug 27, 2018 at 06:48:58PM +0200, Vitaly Kuznetsov wrote: > Using hypercall for sending IPIs is faster because this allows to specify > any number of vCPUs (even > 64 with sparse CPU set), the whole procedure > will take only one VMEXIT. > > Current Hyper-V TLFS (v5.0b) claims that

[PATCH v5 5/5] KVM: x86: hyperv: implement PV IPI send hypercalls

2018-08-27 Thread Vitaly Kuznetsov
Using hypercall for sending IPIs is faster because this allows to specify any number of vCPUs (even > 64 with sparse CPU set), the whole procedure will take only one VMEXIT. Current Hyper-V TLFS (v5.0b) claims that HvCallSendSyntheticClusterIpi hypercall can't be 'fast' (passing parameters

[PATCH v5 5/5] KVM: x86: hyperv: implement PV IPI send hypercalls

2018-08-27 Thread Vitaly Kuznetsov
Using hypercall for sending IPIs is faster because this allows to specify any number of vCPUs (even > 64 with sparse CPU set), the whole procedure will take only one VMEXIT. Current Hyper-V TLFS (v5.0b) claims that HvCallSendSyntheticClusterIpi hypercall can't be 'fast' (passing parameters