Re: [Xen-devel] [PATCH RFC 03/13] xen: mask event channels while changing affinity

2014-01-03 Thread Konrad Rzeszutek Wilk 
On Tue, Dec 24, 2013 at 12:20:52PM +0100, Roger Pau Monne wrote:
 Event channels should be masked while chaning affinity, or else we
changing

 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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[PATCH RFC 03/13] xen: mask event channels while changing affinity

2013-12-24 Thread Roger Pau Monne 
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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