From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54898) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X3g5D-0000nC-Sp for qemu-devel@nongnu.org; Sun, 06 Jul 2014 02:38:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1X3g57-00081g-N3 for qemu-devel@nongnu.org; Sun, 06 Jul 2014 02:37:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36332) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X3g57-00080C-F2 for qemu-devel@nongnu.org; Sun, 06 Jul 2014 02:37:49 -0400 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s666bkhX020132 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Sun, 6 Jul 2014 02:37:47 -0400 Date: Sun, 6 Jul 2014 08:39:53 +0300 From: "Michael S. Tsirkin" Message-ID: <20140706053953.GA5007@redhat.com> References: <1404467029-16028-1-git-send-email-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1404467029-16028-1-git-send-email-pbonzini@redhat.com> Subject: Re: [Qemu-devel] [PATCH] virtio-pci: fix MSI memory region use after tree List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: qemu-devel@nongnu.org, stefanha@redhat.com On Fri, Jul 04, 2014 at 11:43:49AM +0200, Paolo Bonzini wrote: > After memory region QOMification QEMU is stricter in detecting > wrong usage of the memory region API. Here it detected a > memory_region_destroy done before the corresponding > memory_region_del_subregion; the memory_region_destroy is > done by msix_uninit_exclusive_bar, the memory_region_del_subregion > is done by the PCI core's pci_unregister_io_regions before > pc->exit is called. > > The misuse caused an assertion when hot-unplugging virtio > devices. Using the API correctly fixes the assertion. > > Signed-off-by: Paolo Bonzini Applied, thanks! I also added some historical context in the comments (the API misuse was introduced in 06a1307379fcd6c551185ad87679cd7ed896b9ea) > --- > hw/virtio/virtio-pci.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > index 3c42cda..ecb2097 100644 > --- a/hw/virtio/virtio-pci.c > +++ b/hw/virtio/virtio-pci.c > @@ -1003,11 +1003,9 @@ static void virtio_pci_device_plugged(DeviceState *d) > > static void virtio_pci_device_unplugged(DeviceState *d) > { > - PCIDevice *pci_dev = PCI_DEVICE(d); > VirtIOPCIProxy *proxy = VIRTIO_PCI(d); > > virtio_pci_stop_ioeventfd(proxy); > - msix_uninit_exclusive_bar(pci_dev); > } > > static int virtio_pci_init(PCIDevice *pci_dev) > @@ -1024,6 +1022,8 @@ static int virtio_pci_init(PCIDevice *pci_dev) > static void virtio_pci_exit(PCIDevice *pci_dev) > { > VirtIOPCIProxy *proxy = VIRTIO_PCI(pci_dev); > + > + msix_uninit_exclusive_bar(pci_dev); > memory_region_destroy(&proxy->bar); > } > > -- > 1.9.3