From: Jan Beulich jbeulich@suse.com
commit c81d3d24602540f65256f98831d0a25599ea6b87 upstream.
When multiple PCI devices get assigned to a guest right at boot, libxl incrementally populates the backend tree. The writes for the first of the devices trigger the backend watch. In turn xen_pcibk_setup_backend() will set the XenBus state to Initialised, at which point no further reconfigures would happen unless a device got hotplugged. Arrange for reconfigure to also get triggered from the backend watch handler.
Signed-off-by: Jan Beulich jbeulich@suse.com Cc: stable@vger.kernel.org Reviewed-by: Boris Ostrovsky boris.ostrovsky@oracle.com Link: https://lore.kernel.org/r/2337cbd6-94b9-4187-9862-c03ea12e0c61@suse.com Signed-off-by: Juergen Gross jgross@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/xen/xen-pciback/xenbus.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-)
--- a/drivers/xen/xen-pciback/xenbus.c +++ b/drivers/xen/xen-pciback/xenbus.c @@ -358,7 +358,8 @@ out: return err; }
-static int xen_pcibk_reconfigure(struct xen_pcibk_device *pdev) +static int xen_pcibk_reconfigure(struct xen_pcibk_device *pdev, + enum xenbus_state state) { int err = 0; int num_devs; @@ -372,9 +373,7 @@ static int xen_pcibk_reconfigure(struct dev_dbg(&pdev->xdev->dev, "Reconfiguring device ...\n");
mutex_lock(&pdev->dev_lock); - /* Make sure we only reconfigure once */ - if (xenbus_read_driver_state(pdev->xdev->nodename) != - XenbusStateReconfiguring) + if (xenbus_read_driver_state(pdev->xdev->nodename) != state) goto out;
err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename, "num_devs", "%d", @@ -499,6 +498,10 @@ static int xen_pcibk_reconfigure(struct } }
+ if (state != XenbusStateReconfiguring) + /* Make sure we only reconfigure once. */ + goto out; + err = xenbus_switch_state(pdev->xdev, XenbusStateReconfigured); if (err) { xenbus_dev_fatal(pdev->xdev, err, @@ -524,7 +527,7 @@ static void xen_pcibk_frontend_changed(s break;
case XenbusStateReconfiguring: - xen_pcibk_reconfigure(pdev); + xen_pcibk_reconfigure(pdev, XenbusStateReconfiguring); break;
case XenbusStateConnected: @@ -663,6 +666,15 @@ static void xen_pcibk_be_watch(struct xe xen_pcibk_setup_backend(pdev); break;
+ case XenbusStateInitialised: + /* + * We typically move to Initialised when the first device was + * added. Hence subsequent devices getting added may need + * reconfiguring. + */ + xen_pcibk_reconfigure(pdev, XenbusStateInitialised); + break; + default: break; }