KVM: arm/arm64: vITS: Add MSI translation helpers
The whole MSI injection process is fairly monolithic. An MSI write
gets turned into an injected LPI in one swift go. But this is actually
a more fine-grained process:
- First, a virtual ITS gets selected using the doorbell address
- Then the DevID/EventID pair gets translated into an LPI
- Finally the LPI is injected
Since the GICv4 code needs the first two steps in order to match
an IRQ routing entry to an LPI, let's expose them as helpers,
and refactor the existing code to use them
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 40791c1..1de4e68 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -505,19 +505,11 @@
return 0;
}
-/*
- * Find the target VCPU and the LPI number for a given devid/eventid pair
- * and make this IRQ pending, possibly injecting it.
- * Must be called with the its_lock mutex held.
- * Returns 0 on success, a positive error value for any ITS mapping
- * related errors and negative error values for generic errors.
- */
-static int vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its,
- u32 devid, u32 eventid)
+int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
+ u32 devid, u32 eventid, struct vgic_irq **irq)
{
struct kvm_vcpu *vcpu;
struct its_ite *ite;
- unsigned long flags;
if (!its->enabled)
return -EBUSY;
@@ -533,26 +525,61 @@
if (!vcpu->arch.vgic_cpu.lpis_enabled)
return -EBUSY;
- spin_lock_irqsave(&ite->irq->irq_lock, flags);
- ite->irq->pending_latch = true;
- vgic_queue_irq_unlock(kvm, ite->irq, flags);
-
+ *irq = ite->irq;
return 0;
}
-static struct vgic_io_device *vgic_get_its_iodev(struct kvm_io_device *dev)
+struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi)
{
+ u64 address;
+ struct kvm_io_device *kvm_io_dev;
struct vgic_io_device *iodev;
- if (dev->ops != &kvm_io_gic_ops)
- return NULL;
+ if (!vgic_has_its(kvm))
+ return ERR_PTR(-ENODEV);
- iodev = container_of(dev, struct vgic_io_device, dev);
+ if (!(msi->flags & KVM_MSI_VALID_DEVID))
+ return ERR_PTR(-EINVAL);
+ address = (u64)msi->address_hi << 32 | msi->address_lo;
+
+ kvm_io_dev = kvm_io_bus_get_dev(kvm, KVM_MMIO_BUS, address);
+ if (!kvm_io_dev)
+ return ERR_PTR(-EINVAL);
+
+ if (kvm_io_dev->ops != &kvm_io_gic_ops)
+ return ERR_PTR(-EINVAL);
+
+ iodev = container_of(kvm_io_dev, struct vgic_io_device, dev);
if (iodev->iodev_type != IODEV_ITS)
- return NULL;
+ return ERR_PTR(-EINVAL);
- return iodev;
+ return iodev->its;
+}
+
+/*
+ * Find the target VCPU and the LPI number for a given devid/eventid pair
+ * and make this IRQ pending, possibly injecting it.
+ * Must be called with the its_lock mutex held.
+ * Returns 0 on success, a positive error value for any ITS mapping
+ * related errors and negative error values for generic errors.
+ */
+static int vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its,
+ u32 devid, u32 eventid)
+{
+ struct vgic_irq *irq = NULL;
+ unsigned long flags;
+ int err;
+
+ err = vgic_its_resolve_lpi(kvm, its, devid, eventid, &irq);
+ if (err)
+ return err;
+
+ spin_lock_irqsave(&irq->irq_lock, flags);
+ irq->pending_latch = true;
+ vgic_queue_irq_unlock(kvm, irq, flags);
+
+ return 0;
}
/*
@@ -563,30 +590,16 @@
*/
int vgic_its_inject_msi(struct kvm *kvm, struct kvm_msi *msi)
{
- u64 address;
- struct kvm_io_device *kvm_io_dev;
- struct vgic_io_device *iodev;
+ struct vgic_its *its;
int ret;
- if (!vgic_has_its(kvm))
- return -ENODEV;
+ its = vgic_msi_to_its(kvm, msi);
+ if (IS_ERR(its))
+ return PTR_ERR(its);
- if (!(msi->flags & KVM_MSI_VALID_DEVID))
- return -EINVAL;
-
- address = (u64)msi->address_hi << 32 | msi->address_lo;
-
- kvm_io_dev = kvm_io_bus_get_dev(kvm, KVM_MMIO_BUS, address);
- if (!kvm_io_dev)
- return -EINVAL;
-
- iodev = vgic_get_its_iodev(kvm_io_dev);
- if (!iodev)
- return -EINVAL;
-
- mutex_lock(&iodev->its->its_lock);
- ret = vgic_its_trigger_msi(kvm, iodev->its, msi->devid, msi->data);
- mutex_unlock(&iodev->its->its_lock);
+ mutex_lock(&its->its_lock);
+ ret = vgic_its_trigger_msi(kvm, its, msi->devid, msi->data);
+ mutex_unlock(&its->its_lock);
if (ret < 0)
return ret;
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 4f8aecb..0ac8504 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -237,4 +237,8 @@
}
}
+int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
+ u32 devid, u32 eventid, struct vgic_irq **irq);
+struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi);
+
#endif