On Mon, Apr 18, 2011 at 11:03:59PM +0200, Alexander Graf wrote: > > On 18.04.2011, at 21:06, Aurelien Jarno wrote: > > > On Fri, Apr 15, 2011 at 05:32:51PM +0200, Alexander Graf wrote: > >> The s390x virtio bus keeps management information on virtio after the top > >> of the guest's RAM. We need to be able to tell the guest the size of its > >> RAM (without virtio stuff), but also be able to trap when the guest > >> accesses > >> RAM outside of its scope (including virtio stuff). > >> > >> So we need a variable telling us the size of the virtio stuff, so we can > >> calculate the highest available RAM address from that. > >> > >> While at it, also increase the maximum number of virtio pages, so we play > >> along well with more recent kernels that spawn a ridiculous number of > >> virtio > >> console adapters. > >> > >> Signed-off-by: Alexander Graf <ag...@suse.de> > >> --- > >> hw/s390-virtio-bus.c | 3 +++ > >> hw/s390-virtio-bus.h | 2 +- > >> target-s390x/cpu.h | 3 +++ > >> 3 files changed, 7 insertions(+), 1 deletions(-) > >> > >> diff --git a/hw/s390-virtio-bus.c b/hw/s390-virtio-bus.c > >> index bb49e39..a90963b 100644 > >> --- a/hw/s390-virtio-bus.c > >> +++ b/hw/s390-virtio-bus.c > >> @@ -60,6 +60,9 @@ static const VirtIOBindings virtio_s390_bindings; > >> > >> static ram_addr_t s390_virtio_device_num_vq(VirtIOS390Device *dev); > >> > >> +/* length of VirtIO device pages */ > >> +target_phys_addr_t virtio_size = S390_DEVICE_PAGES * TARGET_PAGE_SIZE; > >> + > > > > If this variable is never written, can it be declared const? > > Does that improve anything for exported variables? Do they get put into a ro > section then? >
Unfortunately, that will still be an exported variable, and it's a pitty to use that just because we can't have a #define in hw/* included in target-*/* . That said I just realized that a lot of target are actually doing that, maybe it's the solution here. Adding a const here will clearly show to people reading the code that it's nothing more than advanced #define. -- Aurelien Jarno GPG: 1024D/F1BCDB73 aurel...@aurel32.net http://www.aurel32.net
