How much of the rate controlling work and your interface design has been going into the public Xen tree? I know that Xen has always been lacking proper network resource control features (for non-Solaris systems at least). Is Crossbow fully integrated with the Xen API and management tools?
Thanks, Anna > -----Original Message----- > From: Sunay Tripathi [mailto:Sunay.Tripathi at Sun.Com] > Sent: 10 January 2008 07:58 > To: Fischer, Anna > Cc: crossbow-discuss at opensolaris.org > Subject: Re: [crossbow-discuss] Crossbow and HW-assisted > virtualization > > Anna, > > Yes, you are correct that getting Xen dom0 out of the picture > for domU (guest) to outside communication is good. Crossbow > is providing the framework to do just that. Their are various > terms used like Hybrid I/O (for SPARC implementation) and it > can be done with existing NICs like Sun's Neptune and > Neterion's 10Gb NICs but primarily on SPARC. With IOV, we > will get the needed IOMMU protection to achieve this with any > IOV capable NIC. And yes, if you directly map the DMA channel > and associated Rx ring into a domU, the bandwidth > limiting/guarantees, priority and CPU association becomes > moot because you are dependent on "dynamic polling" from MAC > layer for some of these features. The moment the MAC layer is > part of domU (or guest OS) and controlled by a hostile > entity, theoretically they can circumvent the MAC layer > running in domU (which they control). > > So we build more smarts into the system where the highest > priority VNICs which have unrestricted access are the ones > that get to use these feature while others who have a B/W > limit/guarantee specified get to go through the dom0 where we > don't have to worry about it. > > As part of the MAC layer design, we implement a pseudo H/W > layer which has its S/W classification (more powerful than > the H/W) and S/W rings (called soft rings) etc. They can have > H/W resources associated with them (like Rx/Tx rings or > Intel's VMDq and H/W classification) in which case the pseudo > H/W layer is pass through but it allows us to move H/W > resources in and out of any VNICs (or flows) as and when we > want it. Also, this allows us to provide the uniform > capabilities from the stack without depending on the type of > NIC and its capabilities. You can create 1000s of VNICs and > Flows with their associated properties (like B/W limits, > priorities, degree of fanout, CPU bindings, etc) and the most > important ones get to use whatever H/W support is available. > > Cheers, > Sunay > > Fischer, Anna wrote: > > A current trend in virtualization seems to be to move more > > functionality into hardware and also to remove the hypervisor (like > > e.g. Xen) from the main I/O > > data path. This means that VMs can directly transmit on > the physical > hardware (that might be shared with between > multiple VMs, e.g. > through PCI-SIG > > IOV capabilities) which has a big positive performance > impact. Do you > > support this kind of direct I/O with Crossbow? I can imagine that > > it's > > difficult to do rate (bandwidth) controlling with such a > design, and > > this seems to be one of the most important features of Crossbow. > > > > Also, can Crossbow make use of new Intel VT-d features? If not, is > > this something you look at for future work? > > > > Thanks, > > Anna > > > >> -----Original Message----- > >> From: Roamer.Lu at sun.com [mailto:Roamer.Lu at sun.com] On Behalf Of > >> Yunsong (Roamer) Lu > >> Sent: 09 January 2008 15:22 > >> To: Fischer, Anna > >> Cc: crossbow-discuss at opensolaris.org > >> Subject: Re: [crossbow-discuss] Crossbow and HW-assisted > >> virtualization > >> > >> Hi Anna, > >> Current Crossbow architecture doesn't make use of PCI-SIG IOV > >> functionalities. In fact, Crossbow can virtualize any NIC even the > >> hardware doesn't support any PCI-SIG IOV technologies. > >> > >> Crossbow framework manage all hardware resources exposed by driver > >> and hardware so that IOV-capable NICs can be handled well if the > >> driver can configure the device properly. > >> > >> We are considering to have explicit interfaces for IOV > >> functionalities in the future. > >> > >> Thanks, > >> > >> Roamer > >> > >> Fischer, Anna wrote: > >>> In what way does Crossbow make use of functionalities of > >> PCI-SIG IOV-capable NICs that export multiple virtual NICs > to the OS? > >> Is this already supported in the current Crossbow > implementation and > >> if yes, how much performance impact does it have to use > IOV-capable > >> NICs with Crossbow? > >>> Thanks, > >>> Anna > >>> _______________________________________________ > >>> crossbow-discuss mailing list > >>> crossbow-discuss at opensolaris.org > >>> http://mail.opensolaris.org/mailman/listinfo/crossbow-discuss > >> -- > >> > >> # telnet (650)-786-6759 (x86759) > >> Connected to Solaris.Sun.COM. > >> login: Lu, Yunsong > >> Last login: January 2, 2007 from beyond.sfbay > >> Yunsong.Lu at Sun.COM v1.03 Since Mon Dec. 22, 2003 > >> [Roamer at Solaris Networking]# cd .. > >> > > _______________________________________________ > > crossbow-discuss mailing list > > crossbow-discuss at opensolaris.org > > http://mail.opensolaris.org/mailman/listinfo/crossbow-discuss > > > -- > Sunay Tripathi > Distinguished Engineer > Solaris Core Operating System > Sun MicroSystems Inc. > > Solaris Networking: > http://www.opensolaris.org/os/community/networking > Project Crossbow: http://www.opensolaris.org/os/project/crossbow > > >
