From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:40199) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XRMTd-0004Ch-RE for qemu-devel@nongnu.org; Tue, 09 Sep 2014 10:33:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XRMTU-0007NP-9q for qemu-devel@nongnu.org; Tue, 09 Sep 2014 10:33:01 -0400 Date: Tue, 9 Sep 2014 17:27:58 +0300 From: "Michael S. Tsirkin" Message-ID: <20140909142758.GB13476@redhat.com> References: <1410192283-4026-1-git-send-email-mst@redhat.com> <20140909141338.16792.15555@loki> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140909141338.16792.15555@loki> 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 Roth Cc: Jan Kiszka , qemu-devel@nongnu.org, Anthony Liguori , qemu-stable@nongnu.org On Tue, Sep 09, 2014 at 09:13:38AM -0500, Michael Roth wrote: > Quoting Michael S. Tsirkin (2014-09-08 11:05:02) > > 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. > > I've already backed out the other patch, and it looks we'll have to stick > with that for now with the release being tomorrow. That's fine. > Will queue these back > up for 2.1.2 though. > > > > 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