On Fri, 20 May 2022 21:51:07 +0100
Will Deacon <will@xxxxxxxxxx> wrote:
Hi,
> On Fri, 20 May 2022 14:37:04 +0000, Keir Fraser wrote:
> > While playing with kvmtool's virtio_balloon device I found a couple of
> > niggling issues with the printing of memory stats. Please consider
> > these fairly trivial fixes.
Unfortunately patch 2/2 breaks compilation on userland with older kernel
headers, like Ubuntu 18.04:
...
CC builtin-stat.o
builtin-stat.c: In function 'do_memstat':
builtin-stat.c:86:8: error: 'VIRTIO_BALLOON_S_HTLB_PGALLOC' undeclared (first use in this function); did you mean 'VIRTIO_BALLOON_S_AVAIL'?
case VIRTIO_BALLOON_S_HTLB_PGALLOC:
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
VIRTIO_BALLOON_S_AVAIL
(repeated for VIRTIO_BALLOON_S_HTLB_PGFAIL and VIRTIO_BALLOON_S_CACHES).
I don't quite remember what we did here in the past in those cases,
conditionally redefine the symbols in a local header, or protect the
new code with an #ifdef?
I would lean towards the former (and hacking this in works), but then we
would need to redefine VIRTIO_BALLOON_S_NR, to encompass the new symbols,
which sounds fragile.
Happy to send a patch if we agree on an approach.
Cheers,
Andre
> >
> > Keir Fraser (2):
> > virtio/balloon: Fix a crash when collecting stats
> > stat: Add descriptions for new virtio_balloon stat types
> >
> > [...]
>
> Applied to kvmtool (master), thanks!
>
> [1/2] virtio/balloon: Fix a crash when collecting stats
> https://git.kernel.org/will/kvmtool/c/3a13530ae99a
> [2/2] stat: Add descriptions for new virtio_balloon stat types
> https://git.kernel.org/will/kvmtool/c/bc77bf49df6e
>
> Cheers,
