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-rw-r--r--main/xen/xsa343-2.patch295
1 files changed, 295 insertions, 0 deletions
diff --git a/main/xen/xsa343-2.patch b/main/xen/xsa343-2.patch
new file mode 100644
index 0000000000..b8eb4998f1
--- /dev/null
+++ b/main/xen/xsa343-2.patch
@@ -0,0 +1,295 @@
+From: Jan Beulich <jbeulich@suse.com>
+Subject: evtchn: convert per-channel lock to be IRQ-safe
+
+... in order for send_guest_{global,vcpu}_virq() to be able to make use
+of it.
+
+This is part of XSA-343.
+
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+Acked-by: Julien Grall <jgrall@amazon.com>
+---
+v6: New.
+---
+TBD: This is the "dumb" conversion variant. In a couple of cases the
+ slightly simpler spin_{,un}lock_irq() could apparently be used.
+
+--- a/xen/common/event_channel.c
++++ b/xen/common/event_channel.c
+@@ -248,6 +248,7 @@ static long evtchn_alloc_unbound(evtchn_
+ int port;
+ domid_t dom = alloc->dom;
+ long rc;
++ unsigned long flags;
+
+ d = rcu_lock_domain_by_any_id(dom);
+ if ( d == NULL )
+@@ -263,14 +264,14 @@ static long evtchn_alloc_unbound(evtchn_
+ if ( rc )
+ goto out;
+
+- spin_lock(&chn->lock);
++ spin_lock_irqsave(&chn->lock, flags);
+
+ chn->state = ECS_UNBOUND;
+ if ( (chn->u.unbound.remote_domid = alloc->remote_dom) == DOMID_SELF )
+ chn->u.unbound.remote_domid = current->domain->domain_id;
+ evtchn_port_init(d, chn);
+
+- spin_unlock(&chn->lock);
++ spin_unlock_irqrestore(&chn->lock, flags);
+
+ alloc->port = port;
+
+@@ -283,26 +284,32 @@ static long evtchn_alloc_unbound(evtchn_
+ }
+
+
+-static void double_evtchn_lock(struct evtchn *lchn, struct evtchn *rchn)
++static unsigned long double_evtchn_lock(struct evtchn *lchn,
++ struct evtchn *rchn)
+ {
+- if ( lchn < rchn )
++ unsigned long flags;
++
++ if ( lchn <= rchn )
+ {
+- spin_lock(&lchn->lock);
+- spin_lock(&rchn->lock);
++ spin_lock_irqsave(&lchn->lock, flags);
++ if ( lchn != rchn )
++ spin_lock(&rchn->lock);
+ }
+ else
+ {
+- if ( lchn != rchn )
+- spin_lock(&rchn->lock);
++ spin_lock_irqsave(&rchn->lock, flags);
+ spin_lock(&lchn->lock);
+ }
++
++ return flags;
+ }
+
+-static void double_evtchn_unlock(struct evtchn *lchn, struct evtchn *rchn)
++static void double_evtchn_unlock(struct evtchn *lchn, struct evtchn *rchn,
++ unsigned long flags)
+ {
+- spin_unlock(&lchn->lock);
+ if ( lchn != rchn )
+- spin_unlock(&rchn->lock);
++ spin_unlock(&lchn->lock);
++ spin_unlock_irqrestore(&rchn->lock, flags);
+ }
+
+ static long evtchn_bind_interdomain(evtchn_bind_interdomain_t *bind)
+@@ -312,6 +319,7 @@ static long evtchn_bind_interdomain(evtc
+ int lport, rport = bind->remote_port;
+ domid_t rdom = bind->remote_dom;
+ long rc;
++ unsigned long flags;
+
+ if ( rdom == DOMID_SELF )
+ rdom = current->domain->domain_id;
+@@ -347,7 +355,7 @@ static long evtchn_bind_interdomain(evtc
+ if ( rc )
+ goto out;
+
+- double_evtchn_lock(lchn, rchn);
++ flags = double_evtchn_lock(lchn, rchn);
+
+ lchn->u.interdomain.remote_dom = rd;
+ lchn->u.interdomain.remote_port = rport;
+@@ -364,7 +372,7 @@ static long evtchn_bind_interdomain(evtc
+ */
+ evtchn_port_set_pending(ld, lchn->notify_vcpu_id, lchn);
+
+- double_evtchn_unlock(lchn, rchn);
++ double_evtchn_unlock(lchn, rchn, flags);
+
+ bind->local_port = lport;
+
+@@ -387,6 +395,7 @@ int evtchn_bind_virq(evtchn_bind_virq_t
+ struct domain *d = current->domain;
+ int virq = bind->virq, vcpu = bind->vcpu;
+ int rc = 0;
++ unsigned long flags;
+
+ if ( (virq < 0) || (virq >= ARRAY_SIZE(v->virq_to_evtchn)) )
+ return -EINVAL;
+@@ -424,14 +433,14 @@ int evtchn_bind_virq(evtchn_bind_virq_t
+
+ chn = evtchn_from_port(d, port);
+
+- spin_lock(&chn->lock);
++ spin_lock_irqsave(&chn->lock, flags);
+
+ chn->state = ECS_VIRQ;
+ chn->notify_vcpu_id = vcpu;
+ chn->u.virq = virq;
+ evtchn_port_init(d, chn);
+
+- spin_unlock(&chn->lock);
++ spin_unlock_irqrestore(&chn->lock, flags);
+
+ v->virq_to_evtchn[virq] = bind->port = port;
+
+@@ -448,6 +457,7 @@ static long evtchn_bind_ipi(evtchn_bind_
+ struct domain *d = current->domain;
+ int port, vcpu = bind->vcpu;
+ long rc = 0;
++ unsigned long flags;
+
+ if ( domain_vcpu(d, vcpu) == NULL )
+ return -ENOENT;
+@@ -459,13 +469,13 @@ static long evtchn_bind_ipi(evtchn_bind_
+
+ chn = evtchn_from_port(d, port);
+
+- spin_lock(&chn->lock);
++ spin_lock_irqsave(&chn->lock, flags);
+
+ chn->state = ECS_IPI;
+ chn->notify_vcpu_id = vcpu;
+ evtchn_port_init(d, chn);
+
+- spin_unlock(&chn->lock);
++ spin_unlock_irqrestore(&chn->lock, flags);
+
+ bind->port = port;
+
+@@ -509,6 +519,7 @@ static long evtchn_bind_pirq(evtchn_bind
+ struct pirq *info;
+ int port = 0, pirq = bind->pirq;
+ long rc;
++ unsigned long flags;
+
+ if ( (pirq < 0) || (pirq >= d->nr_pirqs) )
+ return -EINVAL;
+@@ -541,14 +552,14 @@ static long evtchn_bind_pirq(evtchn_bind
+ goto out;
+ }
+
+- spin_lock(&chn->lock);
++ spin_lock_irqsave(&chn->lock, flags);
+
+ chn->state = ECS_PIRQ;
+ chn->u.pirq.irq = pirq;
+ link_pirq_port(port, chn, v);
+ evtchn_port_init(d, chn);
+
+- spin_unlock(&chn->lock);
++ spin_unlock_irqrestore(&chn->lock, flags);
+
+ bind->port = port;
+
+@@ -569,6 +580,7 @@ int evtchn_close(struct domain *d1, int
+ struct evtchn *chn1, *chn2;
+ int port2;
+ long rc = 0;
++ unsigned long flags;
+
+ again:
+ spin_lock(&d1->event_lock);
+@@ -668,14 +680,14 @@ int evtchn_close(struct domain *d1, int
+ BUG_ON(chn2->state != ECS_INTERDOMAIN);
+ BUG_ON(chn2->u.interdomain.remote_dom != d1);
+
+- double_evtchn_lock(chn1, chn2);
++ flags = double_evtchn_lock(chn1, chn2);
+
+ evtchn_free(d1, chn1);
+
+ chn2->state = ECS_UNBOUND;
+ chn2->u.unbound.remote_domid = d1->domain_id;
+
+- double_evtchn_unlock(chn1, chn2);
++ double_evtchn_unlock(chn1, chn2, flags);
+
+ goto out;
+
+@@ -683,9 +695,9 @@ int evtchn_close(struct domain *d1, int
+ BUG();
+ }
+
+- spin_lock(&chn1->lock);
++ spin_lock_irqsave(&chn1->lock, flags);
+ evtchn_free(d1, chn1);
+- spin_unlock(&chn1->lock);
++ spin_unlock_irqrestore(&chn1->lock, flags);
+
+ out:
+ if ( d2 != NULL )
+@@ -705,13 +717,14 @@ int evtchn_send(struct domain *ld, unsig
+ struct evtchn *lchn, *rchn;
+ struct domain *rd;
+ int rport, ret = 0;
++ unsigned long flags;
+
+ if ( !port_is_valid(ld, lport) )
+ return -EINVAL;
+
+ lchn = evtchn_from_port(ld, lport);
+
+- spin_lock(&lchn->lock);
++ spin_lock_irqsave(&lchn->lock, flags);
+
+ /* Guest cannot send via a Xen-attached event channel. */
+ if ( unlikely(consumer_is_xen(lchn)) )
+@@ -746,7 +759,7 @@ int evtchn_send(struct domain *ld, unsig
+ }
+
+ out:
+- spin_unlock(&lchn->lock);
++ spin_unlock_irqrestore(&lchn->lock, flags);
+
+ return ret;
+ }
+@@ -1238,6 +1251,7 @@ int alloc_unbound_xen_event_channel(
+ {
+ struct evtchn *chn;
+ int port, rc;
++ unsigned long flags;
+
+ spin_lock(&ld->event_lock);
+
+@@ -1250,14 +1264,14 @@ int alloc_unbound_xen_event_channel(
+ if ( rc )
+ goto out;
+
+- spin_lock(&chn->lock);
++ spin_lock_irqsave(&chn->lock, flags);
+
+ chn->state = ECS_UNBOUND;
+ chn->xen_consumer = get_xen_consumer(notification_fn);
+ chn->notify_vcpu_id = lvcpu;
+ chn->u.unbound.remote_domid = remote_domid;
+
+- spin_unlock(&chn->lock);
++ spin_unlock_irqrestore(&chn->lock, flags);
+
+ write_atomic(&ld->xen_evtchns, ld->xen_evtchns + 1);
+
+@@ -1280,11 +1294,12 @@ void notify_via_xen_event_channel(struct
+ {
+ struct evtchn *lchn, *rchn;
+ struct domain *rd;
++ unsigned long flags;
+
+ ASSERT(port_is_valid(ld, lport));
+ lchn = evtchn_from_port(ld, lport);
+
+- spin_lock(&lchn->lock);
++ spin_lock_irqsave(&lchn->lock, flags);
+
+ if ( likely(lchn->state == ECS_INTERDOMAIN) )
+ {
+@@ -1294,7 +1309,7 @@ void notify_via_xen_event_channel(struct
+ evtchn_port_set_pending(rd, rchn->notify_vcpu_id, rchn);
+ }
+
+- spin_unlock(&lchn->lock);
++ spin_unlock_irqrestore(&lchn->lock, flags);
+ }
+
+ void evtchn_check_pollers(struct domain *d, unsigned int port)