Re: [Qemu-devel] [PATCH] Citrix PV Bus device

[Peter Maydell]

On 2 July 2013 11:57, Paul Durrant <address@hidden> wrote:
>> -----Original Message-----
>> From: Paolo Bonzini [mailto:address@hidden
>> > So the reason to place the device here is TARGET_PAGE_SIZE...
>> > We really need a way to access that value from common code,
>> > somewhere down my TODO list. :/

We probably don't, because it generally doesn't mean what you
think it does. It's the smallest possible page size the guest
CPU supports, which may not be the same as the actual page
size the guest OS is using.

>> Why does it need to be in pages rather than bytes?

> It doesn't necessarily need to be in pages; it's just a more
> convenient quantity than bytes.

It isn't really more convienient, because the guest would have
to tell QEMU what the page size was. (I'm told that virtio is
planning to move to a simple "just use a byte count" approach.)

thanks
-- PMM