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authorAndre Przywara <andre.przywara@arm.com>2016-07-15 12:43:27 +0100
committerMarc Zyngier <marc.zyngier@arm.com>2016-07-18 18:10:48 +0100
commit5dd4b924e390af426e424d5e52c1b4d1566af817 (patch)
tree8ed824f7d4811703b70ff10449b11f7257f2c063 /virt/kvm/arm/vgic/vgic-mmio-v3.c
parent8a39d00670f0792c1186e442e1dd28fe0326f2ee (diff)
downloadlinux-stericsson-5dd4b924e390af426e424d5e52c1b4d1566af817.tar.gz
KVM: arm/arm64: vgic: Add refcounting for IRQs
In the moment our struct vgic_irq's are statically allocated at guest creation time. So getting a pointer to an IRQ structure is trivial and safe. LPIs are more dynamic, they can be mapped and unmapped at any time during the guest's _runtime_. In preparation for supporting LPIs we introduce reference counting for those structures using the kernel's kref infrastructure. Since private IRQs and SPIs are statically allocated, we avoid actually refcounting them, since they would never be released anyway. But we take provisions to increase the refcount when an IRQ gets onto a VCPU list and decrease it when it gets removed. Also this introduces vgic_put_irq(), which wraps kref_put and hides the release function from the callers. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'virt/kvm/arm/vgic/vgic-mmio-v3.c')
-rw-r--r--virt/kvm/arm/vgic/vgic-mmio-v3.c20
1 files changed, 13 insertions, 7 deletions
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index fc7b6c97acbb..bfcafbd8fa02 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -80,15 +80,17 @@ static unsigned long vgic_mmio_read_irouter(struct kvm_vcpu *vcpu,
{
int intid = VGIC_ADDR_TO_INTID(addr, 64);
struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, NULL, intid);
+ unsigned long ret = 0;
if (!irq)
return 0;
/* The upper word is RAZ for us. */
- if (addr & 4)
- return 0;
+ if (!(addr & 4))
+ ret = extract_bytes(READ_ONCE(irq->mpidr), addr & 7, len);
- return extract_bytes(READ_ONCE(irq->mpidr), addr & 7, len);
+ vgic_put_irq(vcpu->kvm, irq);
+ return ret;
}
static void vgic_mmio_write_irouter(struct kvm_vcpu *vcpu,
@@ -96,15 +98,17 @@ static void vgic_mmio_write_irouter(struct kvm_vcpu *vcpu,
unsigned long val)
{
int intid = VGIC_ADDR_TO_INTID(addr, 64);
- struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, NULL, intid);
-
- if (!irq)
- return;
+ struct vgic_irq *irq;
/* The upper word is WI for us since we don't implement Aff3. */
if (addr & 4)
return;
+ irq = vgic_get_irq(vcpu->kvm, NULL, intid);
+
+ if (!irq)
+ return;
+
spin_lock(&irq->irq_lock);
/* We only care about and preserve Aff0, Aff1 and Aff2. */
@@ -112,6 +116,7 @@ static void vgic_mmio_write_irouter(struct kvm_vcpu *vcpu,
irq->target_vcpu = kvm_mpidr_to_vcpu(vcpu->kvm, irq->mpidr);
spin_unlock(&irq->irq_lock);
+ vgic_put_irq(vcpu->kvm, irq);
}
static unsigned long vgic_mmio_read_v3r_typer(struct kvm_vcpu *vcpu,
@@ -445,5 +450,6 @@ void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg)
irq->pending = true;
vgic_queue_irq_unlock(vcpu->kvm, irq);
+ vgic_put_irq(vcpu->kvm, irq);
}
}