From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36518) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XR1mU-000534-F8 for qemu-devel@nongnu.org; Mon, 08 Sep 2014 12:27:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XR1mP-0001nG-4f for qemu-devel@nongnu.org; Mon, 08 Sep 2014 12:27:06 -0400 Message-ID: <540DD8CB.2000705@siemens.com> Date: Mon, 08 Sep 2014 18:26:51 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <1410192283-4026-1-git-send-email-mst@redhat.com> In-Reply-To: <1410192283-4026-1-git-send-email-mst@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] virtio-pci: enable bus master for old guests List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" , qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Anthony Liguori On 2014-09-08 18:05, Michael S. Tsirkin wrote: > 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 I didn't signed off as I didn't write this patch ;). But you can add my reviewed-by if you like. Jan > 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: > -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux