xen/events: fix binding user event channels to cpus

BugLink: https://bugs.launchpad.net/bugs/1839036
commit bce5963bcb4f9934faa52be323994511d59fd13c upstream.

When binding an interdomain event channel to a vcpu via
IOCTL_EVTCHN_BIND_INTERDOMAIN not only the event channel needs to be
bound, but the affinity of the associated IRQi must be changed, too.
Otherwise the IRQ and the event channel won't be moved to another vcpu
in case the original vcpu they were bound to is going offline.

Cc: <stable@vger.kernel.org> # 4.13
Fixes: c48f64ab472389df ("xen-evtchn: Bind dyn evtchn:qemu-dm interrupt to next online VCPU")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index fe1f16351f9411455b15576cdc83cb6db7d98281..8d49b91d92cd33a343eac0cb9810412cfeaab99b 100644 (file)
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -1293,7 +1293,7 @@ void rebind_evtchn_irq(int evtchn, int irq)
 }
 
 /* Rebind an evtchn so that it gets delivered to a specific cpu */
-int xen_rebind_evtchn_to_cpu(int evtchn, unsigned tcpu)
+static int xen_rebind_evtchn_to_cpu(int evtchn, unsigned int tcpu)
 {
        struct evtchn_bind_vcpu bind_vcpu;
        int masked;
@@ -1327,7 +1327,6 @@ int xen_rebind_evtchn_to_cpu(int evtchn, unsigned tcpu)
 
        return 0;
 }
-EXPORT_SYMBOL_GPL(xen_rebind_evtchn_to_cpu);
 
 static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
                            bool force)
@@ -1341,6 +1340,15 @@ static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
        return ret;
 }
 
+/* To be called with desc->lock held. */
+int xen_set_affinity_evtchn(struct irq_desc *desc, unsigned int tcpu)
+{
+       struct irq_data *d = irq_desc_get_irq_data(desc);
+
+       return set_affinity_irq(d, cpumask_of(tcpu), false);
+}
+EXPORT_SYMBOL_GPL(xen_set_affinity_evtchn);
+
 static void enable_dynirq(struct irq_data *data)
 {
        int evtchn = evtchn_from_irq(data->irq);

diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c
index 9729a64ea1a9847e598ee9e91b6adf0d9fb71511..055123f48039951fe9ea8867a972df8d2cb25dad 100644 (file)
--- a/drivers/xen/evtchn.c
+++ b/drivers/xen/evtchn.c
@@ -447,7 +447,7 @@ static void evtchn_bind_interdom_next_vcpu(int evtchn)
        this_cpu_write(bind_last_selected_cpu, selected_cpu);
 
        /* unmask expects irqs to be disabled */
-       xen_rebind_evtchn_to_cpu(evtchn, selected_cpu);
+       xen_set_affinity_evtchn(desc, selected_cpu);
        raw_spin_unlock_irqrestore(&desc->lock, flags);
 }
 

diff --git a/include/xen/events.h b/include/xen/events.h
index c3e6bc643a7bde4bf770f1c191a472d84c4af945..1650d39decaec96869b194bfdf4a0a910316d6f4 100644 (file)
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -3,6 +3,7 @@
 #define _XEN_EVENTS_H
 
 #include <linux/interrupt.h>
+#include <linux/irq.h>
 #ifdef CONFIG_PCI_MSI
 #include <linux/msi.h>
 #endif
@@ -59,7 +60,7 @@ void evtchn_put(unsigned int evtchn);
 
 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector);
 void rebind_evtchn_irq(int evtchn, int irq);
-int xen_rebind_evtchn_to_cpu(int evtchn, unsigned tcpu);
+int xen_set_affinity_evtchn(struct irq_desc *desc, unsigned int tcpu);
 
 static inline void notify_remote_via_evtchn(int port)
 {