[Xen-devel] [PATCH v8 6/7] xen/arm: clear pending irq queues on do_psci_cpu_on

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

Don't inject irqs to vcpus that are down.

Also when (re)activating a vcpu, clear the vgic and gic irq queues: we
don't want to inject any irqs that couldn't be handled by the vcpu right
before going offline.

Changes in v7:
- call gic_clear_pending_irqs before clearing VPF_down on
do_psci_cpu_on.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
 xen/arch/arm/gic.c        |   12 ++++++++++++
 xen/arch/arm/psci.c       |    3 +++
 xen/arch/arm/vgic.c       |   16 ++++++++++++++--
 xen/include/asm-arm/gic.h |    2 ++
 4 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index 2a44cf8..8d35e0e 100644
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -576,6 +576,18 @@ static void gic_restore_pending_irqs(struct vcpu *v)
 
 }
 
+void gic_clear_pending_irqs(struct vcpu *v)
+{
+    struct pending_irq *p, *t;
+    unsigned long flags;
+
+    spin_lock_irqsave(&gic.lock, flags);
+    v->arch.lr_mask = 0;
+    list_for_each_entry_safe ( p, t, &v->arch.vgic.lr_pending, lr_queue )
+        list_del_init(&p->lr_queue);
+    spin_unlock_irqrestore(&gic.lock, flags);
+}
+
 static void gic_inject_irq_start(void)
 {
     register_t hcr = READ_SYSREG(HCR_EL2);
diff --git a/xen/arch/arm/psci.c b/xen/arch/arm/psci.c
index 1761791..18feead 100644
--- a/xen/arch/arm/psci.c
+++ b/xen/arch/arm/psci.c
@@ -15,6 +15,7 @@
 #include <xen/types.h>
 
 #include <asm/current.h>
+#include <asm/gic.h>
 #include <asm/psci.h>
 
 int do_psci_cpu_on(uint32_t vcpuid, register_t entry_point)
@@ -33,6 +34,8 @@ int do_psci_cpu_on(uint32_t vcpuid, register_t entry_point)
     if ( (ctxt = alloc_vcpu_guest_context()) == NULL )
         return PSCI_DENIED;
 
+    vgic_clear_pending_irqs(v);
+
     memset(ctxt, 0, sizeof(*ctxt));
     ctxt->user_regs.pc64 = (u64) entry_point;
     ctxt->sctlr = SCTLR_BASE;
diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
index 0e9cc4a..f9c1a6b 100644
--- a/xen/arch/arm/vgic.c
+++ b/xen/arch/arm/vgic.c
@@ -641,6 +641,18 @@ struct pending_irq *irq_to_pending(struct vcpu *v, 
unsigned int irq)
     return n;
 }
 
+void vgic_clear_pending_irqs(struct vcpu *v)
+{
+    struct pending_irq *p, *t;
+    unsigned long flags;
+
+    spin_lock_irqsave(&v->arch.vgic.lock, flags);
+    list_for_each_entry_safe ( p, t, &v->arch.vgic.inflight_irqs, inflight )
+        list_del_init(&p->inflight);
+    gic_clear_pending_irqs(v);
+    spin_unlock_irqrestore(&v->arch.vgic.lock, flags);
+}
+
 void vgic_vcpu_inject_irq(struct vcpu *v, unsigned int irq, int virtual)
 {
     int idx = irq >> 2, byte = irq & 0x3;
@@ -652,8 +664,8 @@ void vgic_vcpu_inject_irq(struct vcpu *v, unsigned int irq, 
int virtual)
 
     spin_lock_irqsave(&v->arch.vgic.lock, flags);
 
-    /* irq already pending */
-    if (!list_empty(&n->inflight))
+    /* vcpu offline or irq already pending */
+    if (test_bit(_VPF_down, &v->pause_flags) || !list_empty(&n->inflight))
     {
         spin_unlock_irqrestore(&v->arch.vgic.lock, flags);
         return;
diff --git a/xen/include/asm-arm/gic.h b/xen/include/asm-arm/gic.h
index 0f9f74b..84ebc83 100644
--- a/xen/include/asm-arm/gic.h
+++ b/xen/include/asm-arm/gic.h
@@ -140,12 +140,14 @@ extern void domain_vgic_free(struct domain *d);
 extern int vcpu_vgic_init(struct vcpu *v);
 
 extern void vgic_vcpu_inject_irq(struct vcpu *v, unsigned int irq,int virtual);
+extern void vgic_clear_pending_irqs(struct vcpu *v);
 extern struct pending_irq *irq_to_pending(struct vcpu *v, unsigned int irq);
 
 extern void gic_route_ppis(void);
 extern void gic_route_spis(void);
 
 extern void gic_inject(void);
+extern void gic_clear_pending_irqs(struct vcpu *v);
 extern int gic_events_need_delivery(void);
 
 extern void __cpuinit init_maintenance_interrupt(void);
-- 
1.7.2.5


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