Re: [Qemu-devel] [RFC v1] Add declarations for hierarchical memory region API

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Sun, May 22, 2011 at 3:18 PM, Avi Kivity <avi@xxxxxxxxxx> wrote:
> On 05/22/2011 03:06 PM, Blue Swirl wrote:
>>
>> On Sun, May 22, 2011 at 2:36 PM, Avi Kivity<avi@xxxxxxxxxx> Âwrote:
>> > ÂOn 05/22/2011 12:32 PM, Blue Swirl wrote:
>> >>
>> >> Â>> Â Â> Â Â Â+void memory_region_add_coalescing(MemoryRegion *mr,
>> >> Â>> Â Â> Â Â Â+ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Âtarget_phys_addr_t
>> >> offset,
>> >> Â>> Â Â> Â Â Â+ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Âtarget_phys_addr_t
>> >> size);
>> >> Â>> Â Â> Â Â Â+/* Disable MMIO coalescing for the region. */
>> >> Â>> Â Â> Â Â Â+void memory_region_clear_coalescing(MemoryRegion *mr);
>> >> Â>>
>> >> Â>> Â ÂPerhaps the interface could be more generic, like
>> >> Â>> Â Â+void memory_region_set_property(MemoryRegion *mr, unsigned
>> >> flags);
>> >> Â>> Â Â+void memory_region_clear_property(MemoryRegion *mr, unsigned
>> >> flags);
>> >> Â>>
>> >> Â>
>> >> Â> Â ÂCoalescing is a complex property, not just a boolean attribute.
>> >> ÂWe
>> >> Â> Âprobably
>> >> Â> Â Âwill have a number of boolean attributes later, though.
>> >>
>> >> ÂBut what is the difference between adding coalescing to an area and
>> >> Âsetting the bit property 'coalescing' to an area? At least what you
>> >> Âpropose now is not so complex that it couldn't be handled as a single
>> >> Âbit.
>> >
>> > ÂLook at the API - add_coalescing() sets the coalescing property on a
>> > Âsubrange of the memory region, not the entire region.
>>
>> Right, but doesn't the same apply to any other properties, they may
>> apply to a full range or just a subrange?
>
> We'll know when we have more properties. ÂI expect most will be region-wide.

Since we don't know about those yet, coalescing API could be like you
propose. Later it can be changed to the property API, or leave for
convenience.

>> >
>> > ÂSubregions are first-class regions. ÂIn fact all regions are subregions
>> > Âexcept the root.
>>
>> Oh, I see now. Maybe the comments should describe this. Or perhaps the
>> terms should be something like 'bus/bridge/root' and 'region' instead
>> of 'region' and 'subregion'?
>
> Problem is, memory_region_add_subregion() adds both sub-bridges and leaf
> regions.
>
> It's quite possible that BAR 0 will be a leaf region, and BAR 1 will be a
> sub-bridge.
>
> Can you suggest an alternative naming for the API?

How about
memory_region_container_init()
memory_region_add()
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux