Date: Tue, 24 Dec 2013 12:20:52 +0100 From: Roger Pau Monne <roger.pau@citrix.com> To: <freebsd-xen@freebsd.org>, <freebsd-current@freebsd.org>, <xen-devel@lists.xenproject.org>, <gibbs@freebsd.org>, <jhb@freebsd.org>, <kib@freebsd.org>, <julien.grall@citrix.com> Subject: [PATCH RFC 03/13] xen: mask event channels while changing affinity Message-ID: <1387884062-41154-4-git-send-email-roger.pau@citrix.com> In-Reply-To: <1387884062-41154-1-git-send-email-roger.pau@citrix.com> References: <1387884062-41154-1-git-send-email-roger.pau@citrix.com>
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Event channels should be masked while chaning affinity, or else we
might get spurious/lost interrupts.
---
sys/x86/xen/xen_intr.c | 15 ++++++++++++---
1 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/sys/x86/xen/xen_intr.c b/sys/x86/xen/xen_intr.c
index fd36e68..bc0781e 100644
--- a/sys/x86/xen/xen_intr.c
+++ b/sys/x86/xen/xen_intr.c
@@ -797,7 +797,7 @@ xen_intr_assign_cpu(struct intsrc *base_isrc, u_int apic_id)
struct evtchn_bind_vcpu bind_vcpu;
struct xenisrc *isrc;
u_int to_cpu, vcpu_id;
- int error;
+ int error, masked;
#ifdef XENHVM
if (xen_vector_callback_enabled == 0)
@@ -815,6 +815,12 @@ xen_intr_assign_cpu(struct intsrc *base_isrc, u_int apic_id)
return (EINVAL);
}
+ /*
+ * Mask the event channel port so we don't receive spurious events
+ * while changing affinity.
+ */
+ masked = evtchn_test_and_set_mask(isrc->xi_port);
+
if ((isrc->xi_type == EVTCHN_TYPE_VIRQ) ||
(isrc->xi_type == EVTCHN_TYPE_IPI)) {
/*
@@ -825,8 +831,7 @@ xen_intr_assign_cpu(struct intsrc *base_isrc, u_int apic_id)
evtchn_cpu_mask_port(isrc->xi_cpu, isrc->xi_port);
isrc->xi_cpu = to_cpu;
evtchn_cpu_unmask_port(isrc->xi_cpu, isrc->xi_port);
- mtx_unlock(&xen_intr_isrc_lock);
- return (0);
+ goto out;
}
bind_vcpu.port = isrc->xi_port;
@@ -848,6 +853,10 @@ xen_intr_assign_cpu(struct intsrc *base_isrc, u_int apic_id)
evtchn_cpu_mask_port(to_cpu, isrc->xi_port);
}
}
+
+out:
+ if (!masked)
+ evtchn_unmask_port(isrc->xi_port);
mtx_unlock(&xen_intr_isrc_lock);
return (0);
#else
--
1.7.7.5 (Apple Git-26)
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