Bug 212315

+++ This bug was initially created as a clone of Bug #208895 +++

Description of problem:
The kernel/drivers/xen/blktap/blktap.ko module does not build on ia64:

drivers/xen/blktap/blktapmain.c: In function 'fast_flush_area':
drivers/xen/blktap/blktapmain.c:902: error: implicit declaration of function
'create_lookup_pte_addr'

Version-Release number of selected component (if applicable):
kernel-xen-2.6.18-1.2724.fc6.ia64

blktap has been disabled on ia64 for now:
$ grep TAP configs/*xen*
configs/config-xen-generic:CONFIG_XEN_BLKDEV_TAP=m
configs/config-xen-ia64:# CONFIG_XEN_BLKDEV_TAP is not set

-- Additional comment from chrisw on 2006-10-02 11:29 EST --
Created an attachment (id=137553)
blktap compile fix for ia64


-- Additional comment from chrisw on 2006-10-02 11:36 EST --
Here is a patch that gets things building.  It's a bit of a hack since
it copies create_lookup_pte_addr into ia64 specific source files.  With
this patch the thing builds, and boots.  However each of the blkback, netback
and blktap fail with the same error.  Basically none of the backend drivers are
working on ia64, they each fail in balloon_alloc_empty_page_range() due to
failed __get_free_pages() attempt with large order.

-- Additional comment from sct on 2006-10-02 12:15 EST --
Yes; the backend allocating issue is already being tracked as bug 202971.

-- Additional comment from chrisw on 2006-10-02 12:20 EST --
OK, in that case we could apply the blktap fix to get things working to a point
that they can be debugged.

-- Additional comment from prarit on 2006-10-04 12:00 EST --
Assigning to agriffis.

-- Additional comment from sakaia.com on 2006-10-16 07:15 EST --
GNTMAP_application_map does not support Xen/IA64.
the blktap uses this function, so it does not run.
even if it fixes compilation.

-- Additional comment from yongkang.you on 2006-10-16 22:10 EST --
This bug is still in kernel-xen-2.6.18-1.2784.fc6

-- Additional comment from dzickus on 2006-10-16 22:34 EST --
in kernel-2.6.18-1.2728.el5

-- Additional comment from sct on 2006-10-17 04:41 EST --
Reopening, because the el5 kernel is not a fix for a devel bug!

-- Additional comment from agriffis on 2006-10-25 14:22 EST --
Unfortunately the compile fix for blktap on ia64 isn't nearly enough.  Sure it
allows the module to build, and that's great so that it doesn't need to be
disabled.  However the requisite support isn't in the ia64 hypervisor yet.  See
http://lists.xensource.com/archives/html/xen-ia64-devel/2006-10/msg00206.html

Hopefully this will be fixed upstream in time for RHEL5 release.  Unfortunately
it didn't make FC6