RE: [PATCH 3/3] KVM: x86: hyperv: implement PV IPI send hypercalls

From: KY Srinivasan
Date: Thu Jun 28 2018 - 11:06:08 EST




> -----Original Message-----
> From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> Sent: Thursday, June 28, 2018 8:05 AM
> To: Wanpeng Li <kernellwp@xxxxxxxxx>
> Cc: Radim Krcmar <rkrcmar@xxxxxxxxxx>; kvm <kvm@xxxxxxxxxxxxxxx>;
> Paolo Bonzini <pbonzini@xxxxxxxxxx>; Roman Kagan
> <rkagan@xxxxxxxxxxxxx>; KY Srinivasan <kys@xxxxxxxxxxxxx>; Haiyang
> Zhang <haiyangz@xxxxxxxxxxxxx>; Stephen Hemminger
> <sthemmin@xxxxxxxxxxxxx>; Michael Kelley (EOSG)
> <Michael.H.Kelley@xxxxxxxxxxxxx>; Mohammed Gamal
> <mmorsy@xxxxxxxxxx>; Cathy Avery <cavery@xxxxxxxxxx>; LKML <linux-
> kernel@xxxxxxxxxxxxxxx>
> Subject: Re: [PATCH 3/3] KVM: x86: hyperv: implement PV IPI send
> hypercalls
>
> Wanpeng Li <kernellwp@xxxxxxxxx> writes:
>
> > Hi Paolo and Radim,
> >
> > I have already completed the patches for linux guest/kvm/qemu w/ vCPUs
> > <= 64, however, extra complication as the ex in hyperv should be
> > introduced for vCPUs > 64, so do you think vCPU <=64 is enough for
> > linux guest or should me introduce two hypercall as what hyperv does
> > w/ ex logic?
> >
>
> Neither Paolo nor Radim but as we already have
> #define KVM_MAX_VCPUS 288
> on at least x86, supporting <= 64 vCPUs seems to be too limiting for any
> new functionality.

Agreed.

K. Y
>
> --
> Vitaly