[lkml]   [2009]   [May]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [RFC PATCH 0/3] generic hypercall support
* Gregory Haskins ( wrote:
> Chris Wright wrote:
> > But a free-form hypercall(unsigned long nr, unsigned long *args, size_t count)
> > means hypercall number and arg list must be the same in order for code
> > to call hypercall() in a hypervisor agnostic way.
> Yes, and that is exactly the intention. I think its perhaps the point
> you are missing.

Yes, I was reading this as purely any hypercall, but it seems a bit
more like:

> Today, there is no equivelent of a platform agnostic "iowrite32()" for
> hypercalls so the driver would look like the pseudocode above except
> substitute with kvm_hypercall(), lguest_hypercall(), etc. The proposal
> is to allow the hypervisor to assign a dynamic vector to resources in
> the backend and convey this vector to the guest (such as in PCI
> config-space as mentioned in my example use-case). The provides the
> "address negotiation" function that would normally be done for something
> like a pio port-address. The hypervisor agnostic driver can then use
> this globally recognized address-token coupled with other device-private
> ABI parameters to communicate with the device. This can all occur
> without the core hypervisor needing to understand the details beyond the
> addressing.

VF drivers can also have this issue (and typically use mmio).
I at least have a better idea what your proposal is, thanks for
explanation. Are you able to demonstrate concrete benefit with it yet
(improved latency numbers for example)?


 \ /
  Last update: 2009-05-06 09:25    [W:0.159 / U:8.384 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site