xen/events: switch user event channels to lateeoi model (c44b849c) · Commits · 戴 / test

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:

Jan Beulich <jbeulich@suse.com> Reviewed-by:

Wei Liu <wl@xen.org>

drivers/xen/evtchn.c

+3 −4

Original line number	Diff line number	Diff line
		@@ -167,7 +167,6 @@ static irqreturn_t evtchn_interrupt(int irq, void *data)
		"Interrupt for port %u, but apparently not enabled; per-user %p\n",
		evtchn->port, u);

		disable_irq_nosync(irq);
		evtchn->enabled = false;

		spin_lock(&u->ring_prod_lock);
		@@ -293,7 +292,7 @@ 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);
		}
		}

		@@ -393,7 +392,7 @@ static int evtchn_bind_to_user(struct per_user_data *u, evtchn_port_t port)
		if (rc < 0)
		goto err;

		rc = bind_evtchn_to_irqhandler(port, evtchn_interrupt, 0,
		rc = bind_evtchn_to_irqhandler_lateeoi(port, evtchn_interrupt, 0,
		u->name, evtchn);
		if (rc < 0)
		goto err;

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