Re: [PATCH 2/7] qemu-kvm: Rename kvm_msix_message to KVMMsiMessage

[Avi Kivity <avi@redhat.com>]

On 04/27/2011 05:30 PM, Jan Kiszka wrote:
> On 2011-04-27 16:29, Avi Kivity wrote:
> >  On 04/27/2011 05:04 PM, Jan Kiszka wrote:
> >>>
> >>>   I put kvm_msix_message in pci.h to avoid having every pci device pull in kvm.h
> >>>   is anything wrong with that?  Maybe just rename it to make it generic
> >>>   for msi and leave if where it is.
> >>
> >>  kvm.h shall provide kvm related types, not some unrelated header. That's
> >>  even more important with MSI support for non-PCI devices (aka HPET).
> >
> >  We could have an MSIMessage type that abstracts the general facility,
> >  and let it embed a KVMMsiMessage that contains just the gsi.
>
> Yes, likely also useful for generic MSI delivery services that bypass
> stl_phys.
>

Right, so you can cache the phys_page and apic lookups.

A different layer in which to accomplish this is to have a per-device 
tlb.  So we'd have

     CachedPhysicalAddress msi_fsb_tlb;

     stl_phys_tlb(&msi_fsb_cache, addr, data);

which caches the addr lookup in a 1-entry tlb.  If we have many non-msi 
repeated device writes to the same address, this might be worthwhile.  
 From a quick look at the code, I don't think we do, though.

-- 
error compiling committee.c: too many arguments to function