Re: [PATCH 03/20] migration: remove unreachble RDMA code in save_hook impl

[Eric Blake]

On Tue, May 24, 2022 at 12:02:18PM +0100, Daniel P. Berrangé wrote:
> The QEMUFile 'save_hook' callback has a 'size_t size' parameter.
> 
> The RDMA impl of this has logic that takes different actions
> depending on whether the value is zero or non-zero. It has
> commented out logic that would have taken further actions
> if the value was negative.
> 
> The only place where the 'save_hook' callback is invoked is
> the ram_control_save_page() method, which passes 'size'
> through from its caller. The only caller of this method is
> in turn control_save_page(). This method unconditionally
> passes the 'TARGET_PAGE_SIZE' constant for the 'size' parameter.
> 
> IOW, the only scenario for 'size' that can execute in the
> qemu_rdma_save_page method is 'size > 0'. The remaining code
> has been unreachable since RDMA support was first introduced
> 9 years ago.
> 
> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
>  migration/rdma.c | 120 +++++++++--------------------------------------
>  1 file changed, 21 insertions(+), 99 deletions(-)
>

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org