On 03/04/2012 01:53 PM, Benjamin Herrenschmidt wrote: > On Sun, 2012-03-04 at 12:49 +0200, Avi Kivity wrote: > > On 02/28/2012 11:48 PM, Benjamin Herrenschmidt wrote: > > > On Tue, 2012-02-28 at 14:32 +0200, Avi Kivity wrote: > > > > > > > What if TARGET_PAGE_SIZE > getpagesize()? Or is that impossible? > > > > > > We have yet to encounter such a case. It's not currently possible on > > > power (some old embedded chips could do 1K and 2K page sizes in the TLB > > > iirc but we never supported that in Linux and it's being phased out in > > > HW). > > > > > > I suggest that gets dealt with when/if it needs to, which means probably > > > never :-) > > > > Doesn't ppc support both 4k and 64k pages? Suppose you run a 4k guest > > on a 64k host? > > > > Maybe I'm misremembering or misunderstanding something. > > TARGET_PAGE_SIZE in qemu is always 4k for powerpc, it's a compile time > #define. > > The host kernel exposes the dirty bit map with a bit per -host- kernel > PAGE_SIZE (which is what getpagesize() gets you in qemu). > > My patch makes thus makes things work when the host uses 64K page sizes. > In all cases, the guest page size is irrelevant, this is purely a > problem between the host kernel and qemu.
Right (and I actually knew all this stuff before :( ). -- error compiling committee.c: too many arguments to function
