From 1342ea3b7a14657c3e9f6e38ea3dcc0c2f42939e Mon Sep 17 00:00:00 2001

From: Markus Armbruster <armbru@redhat.com>

Date: Mon, 29 Oct 2018 07:01:37 +0100

Subject: [PATCH 07/22] ivshmem: Fix unplug of device "ivshmem-plain"

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RH-Author: Markus Armbruster <armbru@redhat.com>

Message-id: <20181029070137.21196-4-armbru@redhat.com>

Patchwork-id: 82900

O-Subject: [RHEL-7.6 qemu-kvm-rhev PATCH 3/3] ivshmem: Fix unplug of device "ivshmem-plain"

Bugzilla: 1620373

RH-Acked-by: David Hildenbrand <david@redhat.com>

RH-Acked-by: Igor Mammedov <imammedo@redhat.com>

RH-Acked-by: Laurent Vivier <lvivier@redhat.com>

RH-Acked-by: Marc-André Lureau <marcandre.lureau@redhat.com>

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 <armbru@redhat.com>

Message-Id: <20180926163709.22876-1-armbru@redhat.com>

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

(cherry picked from commit b266f1d1123396f9f5df865508f7555ab0c9582a)

Signed-off-by: Miroslav Rezanina <mrezanin@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 47456b8..28e55d4 100644

--- a/hw/misc/ivshmem.c

+++ b/hw/misc/ivshmem.c

@@ -917,6 +917,7 @@ 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);

@@ -999,6 +1000,10 @@ 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);

@@ -1107,14 +1112,6 @@ 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)

@@ -1123,7 +1120,6 @@ 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;

 }

-- 

1.8.3.1