Re: [PATCH v3 4/5] KVM: Kick resamplefd for split kernel irqchip

2020-03-17 Thread Peter Xu
On Tue, Mar 17, 2020 at 04:12:00PM -0600, Alex Williamson wrote: > On Tue, 17 Mar 2020 17:41:08 -0400 > Peter Xu wrote: > > > On Tue, Mar 17, 2020 at 03:06:46PM -0600, Alex Williamson wrote: > > > > [...] > > > > > > diff --git a/hw/intc/ioapic.c b/hw/intc/ioapic.c > > > > index 15747fe2c2..81a

Re: [PATCH v3 4/5] KVM: Kick resamplefd for split kernel irqchip

2020-03-17 Thread Alex Williamson
On Tue, 17 Mar 2020 17:41:08 -0400 Peter Xu wrote: > On Tue, Mar 17, 2020 at 03:06:46PM -0600, Alex Williamson wrote: > > [...] > > > > diff --git a/hw/intc/ioapic.c b/hw/intc/ioapic.c > > > index 15747fe2c2..81a17cc2b8 100644 > > > --- a/hw/intc/ioapic.c > > > +++ b/hw/intc/ioapic.c > > > @@ -

Re: [PATCH v3 4/5] KVM: Kick resamplefd for split kernel irqchip

2020-03-17 Thread Peter Xu
On Tue, Mar 17, 2020 at 03:06:46PM -0600, Alex Williamson wrote: [...] > > diff --git a/hw/intc/ioapic.c b/hw/intc/ioapic.c > > index 15747fe2c2..81a17cc2b8 100644 > > --- a/hw/intc/ioapic.c > > +++ b/hw/intc/ioapic.c > > @@ -236,8 +236,29 @@ void ioapic_eoi_broadcast(int vector) > > for

Re: [PATCH v3 4/5] KVM: Kick resamplefd for split kernel irqchip

2020-03-17 Thread Alex Williamson
On Tue, 17 Mar 2020 15:50:41 -0400 Peter Xu wrote: > This is majorly only for X86 because that's the only one that supports > split irqchip for now. > > When the irqchip is split, we face a dilemma that KVM irqfd will be > enabled, however the slow irqchip is still running in the userspace. > It

[PATCH v3 4/5] KVM: Kick resamplefd for split kernel irqchip

2020-03-17 Thread Peter Xu
This is majorly only for X86 because that's the only one that supports split irqchip for now. When the irqchip is split, we face a dilemma that KVM irqfd will be enabled, however the slow irqchip is still running in the userspace. It means that the resamplefd in the kernel irqfds won't take any ef