From: Juergen Gross jgross@suse.com
commit c44b849cee8c3ac587da3b0980e01f77500d158c upstream.
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.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/xen/evtchn.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
--- a/drivers/xen/evtchn.c +++ b/drivers/xen/evtchn.c @@ -166,7 +166,6 @@ static irqreturn_t evtchn_interrupt(int "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 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 pe 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;