From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50124) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g6ujM-00042v-8e for qemu-devel@nongnu.org; Mon, 01 Oct 2018 05:43:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1g6ujH-00073D-80 for qemu-devel@nongnu.org; Mon, 01 Oct 2018 05:43:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35154) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1g6ujG-00072U-Vx for qemu-devel@nongnu.org; Mon, 01 Oct 2018 05:43:03 -0400 Received: from smtp.corp.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.26]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0FCF9308FE94 for ; Mon, 1 Oct 2018 09:43:02 +0000 (UTC) References: <20180926163709.22876-1-armbru@redhat.com> From: Paolo Bonzini Message-ID: <55838024-13d8-792c-24f1-f9b4f62b59f2@redhat.com> Date: Mon, 1 Oct 2018 11:42:59 +0200 MIME-Version: 1.0 In-Reply-To: <20180926163709.22876-1-armbru@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] ivshmem: Fix unplug of device "ivshmem-plain" List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster , qemu-devel@nongnu.org On 26/09/2018 18:37, Markus Armbruster 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 > --- > 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; > } > Reviewed-by: Paolo Bonzini Thanks for the fix! Paolo