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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen master] vgic: refuse irq migration when one is already in progress
commit 91ef7364933037b6a8d825405a1c809a72e6152f
Author: Stefano Stabellini <sstabellini@xxxxxxxxxx>
AuthorDate: Wed Apr 5 13:28:43 2017 -0700
Commit: Stefano Stabellini <sstabellini@xxxxxxxxxx>
CommitDate: Thu Apr 6 16:16:04 2017 -0700
vgic: refuse irq migration when one is already in progress
When an irq migration is already in progress, but not yet completed
(GIC_IRQ_GUEST_MIGRATING is set), refuse any other irq migration
requests for the same irq.
This patch implements this approach by returning success or failure from
vgic_migrate_irq, and avoiding irq target changes on failure. It prints
a warning in case the irq migration fails.
It also moves the clear_bit of GIC_IRQ_GUEST_MIGRATING to after the
physical irq affinity has been changed so that all operations regarding
irq migration are completed.
Signed-off-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Reviewed-by: Julien Grall <julien.grall@xxxxxxx>
---
xen/arch/arm/gic.c | 3 ++-
xen/arch/arm/vgic-v2.c | 7 +++----
xen/arch/arm/vgic-v3.c | 7 ++++---
xen/arch/arm/vgic.c | 14 +++++++++-----
xen/include/asm-arm/vgic.h | 2 +-
5 files changed, 19 insertions(+), 14 deletions(-)
diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index f5dc885..da19130 100644
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -510,10 +510,11 @@ static void gic_update_one_lr(struct vcpu *v, int i)
* accesses to inflight.
*/
smp_wmb();
- if ( test_and_clear_bit(GIC_IRQ_GUEST_MIGRATING, &p->status) )
+ if ( test_bit(GIC_IRQ_GUEST_MIGRATING, &p->status) )
{
struct vcpu *v_target = vgic_get_target_vcpu(v, irq);
irq_set_affinity(p->desc, cpumask_of(v_target->processor));
+ clear_bit(GIC_IRQ_GUEST_MIGRATING, &p->status);
}
}
}
diff --git a/xen/arch/arm/vgic-v2.c b/xen/arch/arm/vgic-v2.c
index 0674f7b..dc9f95b 100644
--- a/xen/arch/arm/vgic-v2.c
+++ b/xen/arch/arm/vgic-v2.c
@@ -156,12 +156,11 @@ static void vgic_store_itargetsr(struct domain *d, struct
vgic_irq_rank *rank,
/* Only migrate the vIRQ if the target vCPU has changed */
if ( new_target != old_target )
{
- vgic_migrate_irq(d->vcpu[old_target],
+ if ( vgic_migrate_irq(d->vcpu[old_target],
d->vcpu[new_target],
- virq);
+ virq) )
+ write_atomic(&rank->vcpu[offset], new_target);
}
-
- write_atomic(&rank->vcpu[offset], new_target);
}
}
diff --git a/xen/arch/arm/vgic-v3.c b/xen/arch/arm/vgic-v3.c
index 0679e76..1e9890b 100644
--- a/xen/arch/arm/vgic-v3.c
+++ b/xen/arch/arm/vgic-v3.c
@@ -151,9 +151,10 @@ static void vgic_store_irouter(struct domain *d, struct
vgic_irq_rank *rank,
/* Only migrate the IRQ if the target vCPU has changed */
if ( new_vcpu != old_vcpu )
- vgic_migrate_irq(old_vcpu, new_vcpu, virq);
-
- write_atomic(&rank->vcpu[offset], new_vcpu->vcpu_id);
+ {
+ if ( vgic_migrate_irq(old_vcpu, new_vcpu, virq) )
+ write_atomic(&rank->vcpu[offset], new_vcpu->vcpu_id);
+ }
}
static inline bool vgic_reg64_check_access(struct hsr_dabt dabt)
diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
index 67d75a6..83569b0 100644
--- a/xen/arch/arm/vgic.c
+++ b/xen/arch/arm/vgic.c
@@ -237,18 +237,21 @@ static int vgic_get_virq_priority(struct vcpu *v,
unsigned int virq)
return priority;
}
-void vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int irq)
+bool vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int irq)
{
unsigned long flags;
struct pending_irq *p = irq_to_pending(old, irq);
/* nothing to do for virtual interrupts */
if ( p->desc == NULL )
- return;
+ return true;
/* migration already in progress, no need to do anything */
if ( test_bit(GIC_IRQ_GUEST_MIGRATING, &p->status) )
- return;
+ {
+ gprintk(XENLOG_WARNING, "irq %u migration failed: requested while in
progress\n", irq);
+ return false;
+ }
perfc_incr(vgic_irq_migrates);
@@ -258,7 +261,7 @@ void vgic_migrate_irq(struct vcpu *old, struct vcpu *new,
unsigned int irq)
{
irq_set_affinity(p->desc, cpumask_of(new->processor));
spin_unlock_irqrestore(&old->arch.vgic.lock, flags);
- return;
+ return true;
}
/* If the IRQ is still lr_pending, re-inject it to the new vcpu */
if ( !list_empty(&p->lr_queue) )
@@ -269,7 +272,7 @@ void vgic_migrate_irq(struct vcpu *old, struct vcpu *new,
unsigned int irq)
irq_set_affinity(p->desc, cpumask_of(new->processor));
spin_unlock_irqrestore(&old->arch.vgic.lock, flags);
vgic_vcpu_inject_irq(new, irq);
- return;
+ return true;
}
/* if the IRQ is in a GICH_LR register, set GIC_IRQ_GUEST_MIGRATING
* and wait for the EOI */
@@ -277,6 +280,7 @@ void vgic_migrate_irq(struct vcpu *old, struct vcpu *new,
unsigned int irq)
set_bit(GIC_IRQ_GUEST_MIGRATING, &p->status);
spin_unlock_irqrestore(&old->arch.vgic.lock, flags);
+ return true;
}
void arch_move_irqs(struct vcpu *v)
diff --git a/xen/include/asm-arm/vgic.h b/xen/include/asm-arm/vgic.h
index 894c3f1..544867a 100644
--- a/xen/include/asm-arm/vgic.h
+++ b/xen/include/asm-arm/vgic.h
@@ -314,7 +314,7 @@ extern int vcpu_vgic_free(struct vcpu *v);
extern bool vgic_to_sgi(struct vcpu *v, register_t sgir,
enum gic_sgi_mode irqmode, int virq,
const struct sgi_target *target);
-extern void vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int
irq);
+extern bool vgic_migrate_irq(struct vcpu *old, struct vcpu *new, unsigned int
irq);
/* Reserve a specific guest vIRQ */
extern bool vgic_reserve_virq(struct domain *d, unsigned int virq);
--
generated by git-patchbot for /home/xen/git/xen.git#master
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