Merge tag 'for-linus-5.10b-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull more xen updates from Juergen Gross:

 - A single patch to fix the Xen security issue XSA-331 (malicious
   guests can DoS dom0 by triggering NULL-pointer dereferences or access
   to stale data).

 - A larger series to fix the Xen security issue XSA-332 (malicious
   guests can DoS dom0 by sending events at high frequency leading to
   dom0's vcpus being busy in IRQ handling for elongated times).

* tag 'for-linus-5.10b-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/events: block rogue events for some time
  xen/events: defer eoi in case of excessive number of events
  xen/events: use a common cpu hotplug hook for event channels
  xen/events: switch user event channels to lateeoi model
  xen/pciback: use lateeoi irq binding
  xen/pvcallsback: use lateeoi irq binding
  xen/scsiback: use lateeoi irq binding
  xen/netback: use lateeoi irq binding
  xen/blkback: use lateeoi irq binding
  xen/events: add a new "late EOI" evtchn framework
  xen/events: fix race in evtchn_fifo_unmask()
  xen/events: add a proper barrier to 2-level uevent unmasking
  xen/events: avoid removing an event channel while handling it

1 files changed, 10 insertions, 1 deletions

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 6dfca7265644..bc3421d14576 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -169,6 +169,10 @@ void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue)
 
 	if (more_to_do)
 		napi_schedule(&queue->napi);
+	else if (atomic_fetch_andnot(NETBK_TX_EOI | NETBK_COMMON_EOI,
+				     &queue->eoi_pending) &
+		 (NETBK_TX_EOI | NETBK_COMMON_EOI))
+		xen_irq_lateeoi(queue->tx_irq, 0);
 }
 
 static void tx_add_credit(struct xenvif_queue *queue)
@@ -1643,9 +1647,14 @@ static bool xenvif_ctrl_work_todo(struct xenvif *vif)
 irqreturn_t xenvif_ctrl_irq_fn(int irq, void *data)
 {
 	struct xenvif *vif = data;
+	unsigned int eoi_flag = XEN_EOI_FLAG_SPURIOUS;
 
-	while (xenvif_ctrl_work_todo(vif))
+	while (xenvif_ctrl_work_todo(vif)) {
 		xenvif_ctrl_action(vif);
+		eoi_flag = 0;
+	}
+
+	xen_irq_lateeoi(irq, eoi_flag);
 
 	return IRQ_HANDLED;
 }