Commit b266f1d1 authored by Markus Armbruster's avatar Markus Armbruster
Browse files

ivshmem: Fix unplug of device "ivshmem-plain" 



Commit 2aece63c "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: 2aece63c
Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
Message-Id: <20180926163709.22876-1-armbru@redhat.com>
Reviewed-by: default avatarMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 70b11059

hw/misc/ivshmem.c

+5 −9
Original line number Diff line number Diff line
@@ -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;

}