The following patch is going to use the symbol from the fw_cfg module,
to call the function and write the note location details in the
vmcoreinfo entry, so qemu can produce dumps with the vmcoreinfo note.

CC: Andrew Morton <akpm@linux-foundation.org>
CC: Baoquan He <bhe@redhat.com>
CC: Dave Young <dyoung@redhat.com>
CC: Dave Young <dyoung@redhat.com>
CC: Hari Bathini <hbathini@linux.vnet.ibm.com>
CC: Tony Luck <tony.luck@intel.com>
CC: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Gabriel Somlo <somlo@cmu.edu>
---
 kernel/crash_core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index b3663896278e..2394f0501c65 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -376,6 +376,7 @@ phys_addr_t __weak paddr_vmcoreinfo_note(void)
 {
 	return __pa(vmcoreinfo_note);
 }
+EXPORT_SYMBOL(paddr_vmcoreinfo_note);
 
 static int __init crash_save_vmcoreinfo_init(void)
 {
-- 
2.15.0.277.ga3d2ad2c43

On Thu, Nov 23, 2017 at 03:02:05PM +0100, Marc-André Lureau wrote:
> The following patch is going to use the symbol from the fw_cfg module,
> to call the function and write the note location details in the
> vmcoreinfo entry, so qemu can produce dumps with the vmcoreinfo note.

Sounds like fw_cfg should be moved to be built in only instead of
exporting such a symbol address.

On Thu, Nov 23, 2017 at 06:36:57AM -0800, Christoph Hellwig wrote:
> On Thu, Nov 23, 2017 at 03:02:05PM +0100, Marc-André Lureau wrote:
> > The following patch is going to use the symbol from the fw_cfg module,
> > to call the function and write the note location details in the
> > vmcoreinfo entry, so qemu can produce dumps with the vmcoreinfo note.
> 
> Sounds like fw_cfg should be moved to be built in only instead of
> exporting such a symbol address.

Point is, all fw cfg does is export it on to the hypervisor, so it will
have to be supported forever.  If it's safe to export it to the
hypervisor then for sure it's also safe to export it to modules.

-- 
MST