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-sta...@nongnu.org Reported-by: Greg Kurz <gk...@linux.vnet.ibm.com> Signed-off-by: Jan Kiszka <jan.kis...@siemens.com> Signed-off-by: Michael S. Tsirkin <m...@redhat.com> --- 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