Description of problem:
When rebuilding from the latest srpm, we got the following error and build failed: 

/usr/src/redhat/BUILD/xen-3.1.0-src/tools/ioemu/hw/xen_machine_fv.c: In function
'xen_init_fv':
/usr/src/redhat/BUILD/xen-3.1.0-src/tools/ioemu/hw/xen_machine_fv.c:225: error:
'PAGE_SIZE' undeclared (first use in this function)
/usr/src/redhat/BUILD/xen-3.1.0-src/tools/ioemu/hw/xen_machine_fv.c:225: error:
(Each undeclared identifier is reported only once
/usr/src/redhat/BUILD/xen-3.1.0-src/tools/ioemu/hw/xen_machine_fv.c:225: error:
for each function it appears in.)
/usr/src/redhat/BUILD/xen-3.1.0-src/tools/ioemu/hw/xen_machine_fv.c:235: error:
'PAGE_SHIFT' undeclared (first use in this function)
/usr/src/redhat/BUILD/xen-3.1.0-src/tools/ioemu/hw/xen_machine_fv.c:245: error:
'i' undeclared (first use in this function)

There are two problems in the file xen_machine_fv.c, which was added by the
patch xen-pvfb-01-qemu-fv-machine.patch :
1. A simple one, the variable 'i' is undeclared. 
2. PAGE_SIZE and PAGE_SHIFT are undeclared. 

I have worked out a patch to solve them. Since the /usr/src/include/asm/page.h
in IA64 is just dummy and I can't find any header file which defines the two
macros both in glibc_headers and kernel_headers, I have to use the getpagesize()
from <unistd.h> to get the page_size and then use ffs() from <strings.h> to get
the page_shift.

Version-Release number of selected component (if applicable):
xen-3.1.0-12.fc8.src.rpm

How reproducible:
always

Steps to Reproduce:
1. rpmbuild --rebuild xen-3.1.0-12.fc8.src.rpm
2.
3.
  
Actual results:
build error as described above

Expected results:
build cleanly

Additional info:

patch attached

The two marcos could be found both in /usr/include/asm/page.h and
/usr/include/sys/user.h. But in IA64, they are not there.