> From: Eric Blake [mailto:ebl...@redhat.com] > Sent: Tuesday, 21 March 2017 15:52 > > On 03/21/2017 05:31 PM, Andrew Baumann wrote: > > "long" is 32-bits on win32, but we need to promote it to a 64-bit hwaddr > > before negating, or else the top half of the address is truncated > > > > Signed-off-by: Andrew Baumann <andrew.baum...@microsoft.com> > > --- > > include/hw/virtio/virtio.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h > > index 15efcf2..a0a8543 100644 > > --- a/include/hw/virtio/virtio.h > > +++ b/include/hw/virtio/virtio.h > > @@ -34,7 +34,7 @@ struct VirtQueue; > > static inline hwaddr vring_align(hwaddr addr, > > unsigned long align) > > { > > - return (addr + align - 1) & ~(align - 1); > > + return (addr + align - 1) & ~(hwaddr)(align - 1); > > Why not just use the QEMU_ALIGN_DOWN macro, instead of open-coding it?
Well, this code is aligning up, but yes the ALIGN_UP macro looks like it should also avoid the type promotion problem. This patch is just the minimally-invasive change after discovering the bug. Let me know if you want me to spin another patch with the macro. Andrew
