Re: [PATCH v6 0/5] KVM: VMX: Add Posted Interrupt supporting

[Gleb Natapov <gleb@redhat.com>]

On Mon, Mar 18, 2013 at 02:49:25AM +0000, Zhang, Yang Z wrote:
> Zhang, Yang Z wrote on 2013-03-15:
> > From: Yang Zhang <yang.z.zhang@Intel.com>
> > 
> > The follwoing patches are adding the Posted Interrupt supporting to KVM:
> > The first patch enables the feature 'acknowledge interrupt on vmexit'.Since
> > it is required by Posted interrupt, we need to enable it firstly.
> > 
> > And the subsequent patches are adding the posted interrupt supporting:
> > Posted Interrupt allows APIC interrupts to inject into guest directly
> > without any vmexit.
> > 
> > - When delivering a interrupt to guest, if target vcpu is running,
> >   update Posted-interrupt requests bitmap and send a notification event
> >   to the vcpu. Then the vcpu will handle this interrupt automatically,
> >   without any software involvemnt.
> > - If target vcpu is not running or there already a notification event
> >   pending in the vcpu, do nothing. The interrupt will be handled by
> >   next vm entry
> > NOTE: We don't turn on the Posted Interrupt until the coalesced issue is
> > solved.
> > 
> > Changes from v5 to v6:
> > * Split sync_pir_to_irr into two functions one to query whether PIR is empty
> >   and the other to perform the sync.
> > * Add comments to explain how vmx_sync_pir_to_irr() work.
> > * Rebase on top of KVM upstream.
> > 
> > Changes from v4 to v5:
> > * Add per cpu count for posted IPI handler.
> > * Dont' check irr when delivering interrupt. Since we can not get interrupt
> >   coalesced info with Posted Interrupt. So there is no need to check the
> >   irr. There is another patch will changed current interrupt coalesced
> >   logic. Before it, we will not turn on Posted Interrupt. * Clear
> >   outstanding notification bit after call local_irq_disable, but before
> >   check request. As Marcelo suggested, we can ensure the IPI not lost in
> >   this way * Remove the spinlock. Same as item 2, if not need to get
> >   coalesced info, then no need the lock.
> > * Rebase on top of KVM upstream.
> > 
> > Yang Zhang (5):
> >   KVM: VMX: Enable acknowledge interupt on vmexit
> >   KVM: VMX: Register a new IPI for posted interrupt
> >   KVM: VMX: Check the posted interrupt capability
> >   KVM: VMX: Add the algorithm of deliver posted interrupt
> >   KVM : VMX: Use posted interrupt to deliver virtual interrupt
> >  arch/x86/include/asm/entry_arch.h  |    4 +
> >  arch/x86/include/asm/hardirq.h     |    3 +
> >  arch/x86/include/asm/hw_irq.h      |    1 +
> >  arch/x86/include/asm/irq_vectors.h |    5 +
> >  arch/x86/include/asm/kvm_host.h    |    5 + arch/x86/include/asm/vmx.h 
> >         |    4 + arch/x86/kernel/entry_64.S         |    5 +
> >  arch/x86/kernel/irq.c              |   22 ++++
> >  arch/x86/kernel/irqinit.c          |    4 + arch/x86/kvm/irq.c         
> >         |    3 +- arch/x86/kvm/lapic.c               |   29 ++++-
> >  arch/x86/kvm/lapic.h               |    2 + arch/x86/kvm/svm.c         
> >         |   30 +++++ arch/x86/kvm/vmx.c                 |  223
> >  ++++++++++++++++++++++++++++++++---- arch/x86/kvm/x86.c                
> >  |    8 +- virt/kvm/kvm_main.c                |    1 + 16 files changed,
> >  320 insertions(+), 29 deletions(-)
> Are there any other comments with this patch?
> 
Haven't reviewed it yet, will do ASAP. "Use eoi to track RTC interrupt
delivery status" series is pre-request for this one.

> For TMR issue, since it has nothing to do with APICv, if we really need to handle it later, then we may need a separate patch to fix it. But currently, we may focused on APICv only.
> 
What do you mean by "TMR has nothing to do with APICv"?

--
			Gleb.