Re: [PATCH v5 04/14] softmmu/memory: Pass ram_flags to qemu_ram_alloc_from_fd()

[David Hildenbrand]

On 20.04.21 12:18, Philippe Mathieu-Daudé wrote:
> Hi David,
>
> On 4/20/21 11:52 AM, Philippe Mathieu-Daudé wrote:
> > On 4/13/21 11:14 AM, David Hildenbrand wrote:
> > > Let's pass in ram flags just like we do with qemu_ram_alloc_from_file(),
> > > to clean up and prepare for more flags.
> > >
> > > Simplify the documentation of passed ram flags: Looking at our
> > > documentation of RAM_SHARED and RAM_PMEM is sufficient, no need to be
> > > repetitive.
> > >
> > > Reviewed-by: Peter Xu <peterx@redhat.com>
> > > Signed-off-by: David Hildenbrand <david@redhat.com>
> > > ---
> > >   backends/hostmem-memfd.c | 7 ++++---
> > >   hw/misc/ivshmem.c        | 5 ++---
> > >   include/exec/memory.h    | 9 +++------
> > >   include/exec/ram_addr.h  | 6 +-----
> > >   softmmu/memory.c         | 7 +++----
> > >   5 files changed, 13 insertions(+), 21 deletions(-)
> >
> > Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>
> Actually it would be clearer to define the 0 value, maybe:
>
> #define RAM_NOFLAG     (0 << 0)

This will also turn some code into

ram_flags = backend->share ? RAM_SHARED : RAM_NOFLAG;
ram_flags |= backend->reserve ? RAM_NOFLAG : RAM_NORESERVE;


Looking at other flag users, I barely see any such usage. 
XKB_CONTEXT_NO_FLAGS, ALLOC_NO_FLAGS, and MEM_AFFINITY_NOFLAGS seem to 
be the only ones. That's why I tend to not do it unless there are strong 
opinions.

Thanks!

--
Thanks,

David / dhildenb