[Qemu-devel] Re: [PATCHv3 RFC] qemu-kvm: stop devices on vmstop

[Juan Quintela <quintela@redhat.com>]

"Michael S. Tsirkin" <mst@redhat.com> wrote:
> Stop running devices on vmstop, so that VM does not interact with
> outside world at that time.
>
> Whitelist system handlers which run even when VM is stopped.
> These are specific handlers like monitor, gdbstub, migration.
> I'm not really sure about ui: spice and vnc: do they need to run?

>  
> -int qemu_aio_set_fd_handler(int fd,
> +static int qemu_aio_assign_fd_handler(int fd,
>                              IOHandler *io_read,
>                              IOHandler *io_write,
>                              AioFlushHandler *io_flush,
>                              AioProcessQueue *io_process_queue,
> -                            void *opaque)
> +                            void *opaque, bool system)
>  {

New names much better O:-)

> -        qemu_set_fd_handler2(vs->csock, NULL, vnc_client_read, NULL, vs);
> +        qemu_set_systemk_fd_handler(vs->csock, NULL, vnc_client_read, NULL, vs);

typo?  it would not compile (extra k on syntemk)


> +static inline void call_ioh_fds(IOHandlerRecordList *list,
> +                                  fd_set *rfds, fd_set *wfds)
> +{
> +    IOHandlerRecord *ioh, *pioh;
> +
> +    QLIST_FOREACH_SAFE(ioh, list, next, pioh) {
> +        if (ioh->deleted) {
> +            QLIST_REMOVE(ioh, next);
> +            qemu_free(ioh);
> +            continue;
> +        }
> +        if (ioh->fd_read && FD_ISSET(ioh->fd, rfds)) {
> +            ioh->fd_read(ioh->opaque);
> +            if (!(ioh->fd_read_poll && ioh->fd_read_poll(ioh->opaque)))
> +                FD_CLR(ioh->fd, rfds);
> +        }
> +        if (ioh->fd_write && FD_ISSET(ioh->fd, wfds)) {
> +            ioh->fd_write(ioh->opaque);
> +        }

Notice this loop has been changed to be able that the fd_read to delete
the handle.

> -    }
>  
> -    slirp_select_poll(&rfds, &wfds, &xfds, (ret < 0));
> +        slirp_select_poll(&rfds, &wfds, &xfds, (ret < 0));

white space damage?

I haven't tested it either, to know if changing things to the bottom
handler would improve things.

Later, Juan.