Re: [Qemu-devel] [PATCH] Fix phys memory client - pass guest physical address not region offset

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2011-04-29 17:06, Michael S. Tsirkin wrote:
> On Thu, Apr 28, 2011 at 09:15:23PM -0600, Alex Williamson wrote:
>> When we're trying to get a newly registered phys memory client updated
>> with the current page mappings, we end up passing the region offset
>> (a ram_addr_t) as the start address rather than the actual guest
>> physical memory address (target_phys_addr_t).  If your guest has less
>> than 3.5G of memory, these are coincidentally the same thing.  If

I think this broke even with < 3.5G as phys_offset also encodes the
memory type while region_offset does not. So everything became RAMthis
way, no MMIO was announced.

>> there's more, the region offset for the memory above 4G starts over
>> at 0, so the set_memory client will overwrite it's lower memory entries.
>>
>> Instead, keep track of the guest phsyical address as we're walking the
>> tables and pass that to the set_memory client.
>>
>> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
> 
> Acked-by: Michael S. Tsirkin <mst@redhat.com>
> 
> Given all this, can yo tell how much time does
> it take to hotplug a device with, say, a 40G RAM guest?

Why not collect pages of identical types and report them as one chunk
once the type changes?

Jan

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