Re: [v4 1/3] genirq: Introduce irq_set_vcpu_affinity() to target an interrupt to a VCPU

[Thomas Gleixner <tglx@linutronix.de>]

On Wed, 13 May 2015, Jiang Liu wrote:

> On 2015/4/30 15:06, Feng Wu wrote:
> > With Posted-Interrupts support in Intel CPU and IOMMU, an external
> > interrupt from assigned-devices could be directly delivered to a
> > virtual CPU in a virtual machine. Instead of hacking KVM and Intel
> > IOMMU drivers, we propose a platform independent interface to target
> > an interrupt to a specific virtual CPU in a virtual machine, or set
> > virtual CPU affinity for an interrupt.
> > 
> > By adopting this new interface and the hierarchy irqdomain, we could
> > easily support posted-interrupts on Intel platforms, and also provide
> > flexible enough interfaces for other platforms to support similar
> > features.
> > 
> > Here is the usage scenario for this interface:
> > Guest update MSI/MSI-X interrupt configuration
> >         -->QEMU and KVM handle this
> >         -->KVM call this interface (passing posted interrupts descriptor
> >            and guest vector)
> >         -->irq core will transfer the control to IOMMU
> >         -->IOMMU will do the real work of updating IRTE (IRTE has new
> >            format for VT-d Posted-Interrupts)
> 
> Hi Thomas,
> 	Any comments or suggestions about this abstraction interface?

It's on my review list...