github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-06-08 14:42:37 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

xen-pciback: reconfigure also from backend watch handler

Browse Source 
commit c81d3d2460 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>
This commit is contained in:
Jan Beulich 2021-05-18 18:14:07 +02:00 committed by Greg Kroah-Hartman
parent c196031f4f
commit 63a5b38447
1 changed files with 17 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
drivers/xen/xen-pciback/xenbus.c
View File

@ -359,7 +359,8 @@ static int xen_pcibk_publish_pci_root(struct xen_pcibk_device *pdev,
return err; 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 err = 0;
int num_devs; int num_devs;
@ -373,9 +374,7 @@ static int xen_pcibk_reconfigure(struct xen_pcibk_device *pdev)
dev_dbg(&pdev->xdev->dev, "Reconfiguring device ...\n"); dev_dbg(&pdev->xdev->dev, "Reconfiguring device ...\n");
mutex_lock(&pdev->dev_lock); mutex_lock(&pdev->dev_lock);
/* Make sure we only reconfigure once */ if (xenbus_read_driver_state(pdev->xdev->nodename) != state)
if (xenbus_read_driver_state(pdev->xdev->nodename) !=
XenbusStateReconfiguring)
goto out; goto out;
err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename, "num_devs", "%d", err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename, "num_devs", "%d",
@ -500,6 +499,10 @@ static int xen_pcibk_reconfigure(struct xen_pcibk_device *pdev)
} }
} }
if (state != XenbusStateReconfiguring)
/* Make sure we only reconfigure once. */
goto out;
err = xenbus_switch_state(pdev->xdev, XenbusStateReconfigured); err = xenbus_switch_state(pdev->xdev, XenbusStateReconfigured);
if (err) { if (err) {
xenbus_dev_fatal(pdev->xdev, err, xenbus_dev_fatal(pdev->xdev, err,
@ -525,7 +528,7 @@ static void xen_pcibk_frontend_changed(struct xenbus_device *xdev,
break; break;
case XenbusStateReconfiguring: case XenbusStateReconfiguring:
xen_pcibk_reconfigure(pdev); xen_pcibk_reconfigure(pdev, XenbusStateReconfiguring);
break; break;
case XenbusStateConnected: case XenbusStateConnected:
@ -664,6 +667,15 @@ static void xen_pcibk_be_watch(struct xenbus_watch *watch,
xen_pcibk_setup_backend(pdev); xen_pcibk_setup_backend(pdev);
break; 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: default:
break; break;
} }