Instead of disabling the irq when an event is received and enabling it again when handled by the user process use the lateeoi model.
This is part of XSA-332.
This is upstream commit c44b849cee8c3ac587da3b0980e01f77500d158c
Cc: stable@vger.kernel.org Reported-by: Julien Grall julien@xen.org Signed-off-by: Juergen Gross jgross@suse.com Tested-by: Stefano Stabellini sstabellini@kernel.org Reviewed-by: Stefano Stabellini sstabellini@kernel.org Reviewed-by: Jan Beulich jbeulich@suse.com Reviewed-by: Wei Liu wl@xen.org --- drivers/xen/evtchn.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c index 055123f48039..0770f427beb2 100644 --- a/drivers/xen/evtchn.c +++ b/drivers/xen/evtchn.c @@ -166,7 +166,6 @@ static irqreturn_t evtchn_interrupt(int irq, void *data) "Interrupt for port %d, but apparently not enabled; per-user %p\n", evtchn->port, u);
- disable_irq_nosync(irq); evtchn->enabled = false;
spin_lock(&u->ring_prod_lock); @@ -292,7 +291,7 @@ static ssize_t evtchn_write(struct file *file, const char __user *buf, evtchn = find_evtchn(u, port); if (evtchn && !evtchn->enabled) { evtchn->enabled = true; - enable_irq(irq_from_evtchn(port)); + xen_irq_lateeoi(irq_from_evtchn(port), 0); } }
@@ -392,8 +391,8 @@ static int evtchn_bind_to_user(struct per_user_data *u, int port) if (rc < 0) goto err;
- rc = bind_evtchn_to_irqhandler(port, evtchn_interrupt, 0, - u->name, evtchn); + rc = bind_evtchn_to_irqhandler_lateeoi(port, evtchn_interrupt, 0, + u->name, evtchn); if (rc < 0) goto err;