From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50432) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XR1OC-0006qC-Eg for qemu-devel@nongnu.org; Mon, 08 Sep 2014 12:02:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XR1O5-0006iB-SX for qemu-devel@nongnu.org; Mon, 08 Sep 2014 12:02:00 -0400 Date: Mon, 8 Sep 2014 19:05:02 +0300 From: "Michael S. Tsirkin" Message-ID: <1410192283-4026-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Subject: [Qemu-devel] [PATCH] virtio-pci: enable bus master for old guests List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Jan Kiszka , qemu-stable@nongnu.org, Anthony Liguori commit cc943c36faa192cd4b32af8fe5edb31894017d35 pci: Use bus master address space for delivering MSI/MSI-X messages breaks virtio-net for rhel6.[56] x86 guests because they don't enable bus mastering for virtio PCI devices Old guests forgot to enable bus mastering, enable it automatically on DRIVER_OK. Note: we should either back out the original patch from stable or apply this one on top. Cc: qemu-stable@nongnu.org Reported-by: Greg Kurz Signed-off-by: Jan Kiszka Signed-off-by: Michael S. Tsirkin --- hw/virtio/virtio-pci.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index ddb5da1..af937d2 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -320,6 +320,8 @@ static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val) if ((val & VIRTIO_CONFIG_S_DRIVER_OK) && !(proxy->pci_dev.config[PCI_COMMAND] & PCI_COMMAND_MASTER)) { proxy->flags |= VIRTIO_PCI_FLAG_BUS_MASTER_BUG; + memory_region_set_enabled(&proxy->pci_dev.bus_master_enable_region, + true); } break; case VIRTIO_MSI_CONFIG_VECTOR: -- MST