Re: [PATCH 0/4] migration: Remove extra type-checking from vmstate macros

On Wed, Jul 29, 2026 at 07:52:23PM -0300, Fabiano Rosas wrote:
> Hi, this is basically what I ranted about in:
> https://lore.kernel.org/r/[email protected]
> 
> I'm replacing the per-integer-size type checks with a single "int that
> fits in 32bit" check. This allows several lines of duplicated code to
> be removed.
> 
> I haven't changed the macro names in the device code yet. If this
> series gets positive feedback then I'll send per-subsystem patches
> doing that.
> 
> CI run: https://gitlab.com/farosas/qemu/-/pipelines/2716814081
> Also tested:
> - migration-test --full --thorough
> - x86_64 compat run forwards and backwards for previous 3 QEMU releases
> - s390x compat run forwards and backwards for previous 2 QEMU releases
> - ppc64 compat run forwards and backwards for previous QEMU release
> - migration-test smoke ASAN/UBSAN run
> 
> Fabiano Rosas (4):
>   migration: Remove VMSTATE_ARRAY_INT32_UNSAFE
>   migration: Introduce VMStateOffset
>   migration: Remove redundant flags
>   migration: Remove duplicate vmstate macros

Nice work!

I think I was only looking at VBUFFER side and I thought it was fine
sticking with 32bit even signed or not, not a huge deal.  But cleaning up
VARRAY whole thing together looks definitely an improvement.  I definitely
like your version here.

I assume with your series I can drop both of my patches here, right?

  [PATCH v2 1/5] migration: Fix possible overflow in vmstate_handle_alloc()
  https://lore.kernel.org/r/[email protected]
  (I'll still respin with the rest)

  [PATCH] vhost/migration: Fix incorrect size used in inflight->addr in VMSD
  https://lore.kernel.org/r/[email protected]

The only missing piece would be an multiply overflow check in
vmstate_handle_alloc(), if you could add that check too while rewritting
that in patch 1 then I think it'll cover all.

Vladimir's ask in the separate email makes sense: I wonder if we can also
do one step further and merge VBUFFER into VARRAY.

The other trivial thing is, while looking, I found one trivial macro
VMSTATE_PARTIAL_VBUFFER not used; can drop it altogether.

-- 
Peter Xu