Hi
On Wed, Sep 26, 2018 at 8:37 PM Markus Armbruster <arm...@redhat.com> wrote:
>
> Commit 2aece63c8a "hostmem: detect host backend memory is being used
> properly" fixed "ivshmem-plain" to reject memory backends that are
> already in use, and to block their deletion while in use. Two bugs
> escaped review:
>
> * New ivshmem_plain_exit() fails to call ivshmem_exit(). This breaks
> unplug. Reproducer: migration after unplug still fails with
> "Migration is disabled when using feature 'peer mode' in device
> 'ivshmem'".
>
> * It failed to update legacy "ivshmem". Harmless, because it creates
> the memory backend itself, and nothing else should use it.
>
> Fix by moving the two host_memory_backend_set_mapped() calls into
> ivshmem_common_realize() and ivshmem_exit(), guarded by s->hostmem.
>
> Fixes: 2aece63c8a9d2c3a8ff41d2febc4cdeff2633331
> Signed-off-by: Markus Armbruster <arm...@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> ---
> hw/misc/ivshmem.c | 14 +++++---------
> 1 file changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
> index 6febbabcaa..8cb17b9dd4 100644
> --- a/hw/misc/ivshmem.c
> +++ b/hw/misc/ivshmem.c
> @@ -911,6 +911,7 @@ static void ivshmem_common_realize(PCIDevice *dev, Error
> **errp)
> IVSHMEM_DPRINTF("using hostmem\n");
>
> s->ivshmem_bar2 = host_memory_backend_get_memory(s->hostmem);
> + host_memory_backend_set_mapped(s->hostmem, true);
> } else {
> Chardev *chr = qemu_chr_fe_get_driver(&s->server_chr);
> assert(chr);
> @@ -993,6 +994,10 @@ static void ivshmem_exit(PCIDevice *dev)
> vmstate_unregister_ram(s->ivshmem_bar2, DEVICE(dev));
> }
>
> + if (s->hostmem) {
> + host_memory_backend_set_mapped(s->hostmem, false);
> + }
> +
> if (s->peers) {
> for (i = 0; i < s->nb_peers; i++) {
> close_peer_eventfds(s, i);
> @@ -1101,14 +1106,6 @@ static void ivshmem_plain_realize(PCIDevice *dev,
> Error **errp)
> }
>
> ivshmem_common_realize(dev, errp);
> - host_memory_backend_set_mapped(s->hostmem, true);
> -}
> -
> -static void ivshmem_plain_exit(PCIDevice *pci_dev)
> -{
> - IVShmemState *s = IVSHMEM_COMMON(pci_dev);
> -
> - host_memory_backend_set_mapped(s->hostmem, false);
> }
>
> static void ivshmem_plain_class_init(ObjectClass *klass, void *data)
> @@ -1117,7 +1114,6 @@ static void ivshmem_plain_class_init(ObjectClass
> *klass, void *data)
> PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
>
> k->realize = ivshmem_plain_realize;
> - k->exit = ivshmem_plain_exit;
> dc->props = ivshmem_plain_properties;
> dc->vmsd = &ivshmem_plain_vmsd;
> }
> --
> 2.17.1
>
>
--
Marc-André Lureau
