From: Alex Williamson <alex.williamson@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Wu, Feng" <feng.wu@intel.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"joro@8bytes.org" <joro@8bytes.org>,
"avi.kivity@gmail.com" <avi.kivity@gmail.com>,
"eric.auger@linaro.org" <eric.auger@linaro.org>
Subject: Re: [RFC v1 5/5] Call irqbypass update routine when updating irqfd
Date: Fri, 10 Jul 2015 08:11:01 -0600 [thread overview]
Message-ID: <1436537461.1391.255.camel@redhat.com> (raw)
In-Reply-To: <559FBEFE.4000202@redhat.com>
On Fri, 2015-07-10 at 14:47 +0200, Paolo Bonzini wrote:
>
> On 10/07/2015 10:28, Wu, Feng wrote:
> > > Yes, you are right. All we need is the producer information which has been
> > > passed in the register routine. And we can easily make this update logic
> > > inside the consumer. Thanks for your comments!
> >
> > BTW, Paolo & Alex, in VFIO framework, how can we know a vCPU or a guest
> > has assigned devices to it?
>
> See here:
> http://article.gmane.org/gmane.comp.emulators.kvm.devel/137930/raw
In general, VFIO has zero visibility into KVM. VFIO doesn't know or
care what the userspace driver is, whether it's QEMU/KVM, a set of ruby
bindings for VFIO, a DPDK library, etc. As Paolo points out, KVM does
have ways to be told about assigned devices from userspace and probe
some properties, like whether the IOMMU allows non-coherent DMA. These
are handled by the KVM-VFIO pseudo device (virt/kvm/vfio.c). Thanks,
Alex
prev parent reply other threads:[~2015-07-10 14:11 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-10 3:00 [RFC v1 0/5] irq bypass interface implementation for VT-d Posted-interrupts Feng Wu
2015-07-10 3:00 ` [RFC v1 1/5] vfio: Register/unregister irq_bypass_producer Feng Wu
2015-07-10 3:00 ` [RFC v1 2/5] KVM: x86: Update IRTE for posted-interrupts Feng Wu
2015-07-10 3:00 ` [RFC v1 3/5] KVM: Add pointer to 'struct irq_bypass_produce' in 'kvm_kernel_irqfd' Feng Wu
2015-07-10 3:00 ` [RFC v1 4/5] KVM: x86: Add arch specific routines for irqbypass manager Feng Wu
2015-07-10 3:27 ` Alex Williamson
2015-07-10 3:00 ` [RFC v1 5/5] Call irqbypass update routine when updating irqfd Feng Wu
2015-07-10 3:26 ` Alex Williamson
2015-07-10 4:12 ` Wu, Feng
2015-07-10 8:28 ` Wu, Feng
2015-07-10 12:47 ` Paolo Bonzini
2015-07-10 14:11 ` Alex Williamson [this message]
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