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authorAndre Przywara <andre.przywara@arm.com>2016-08-08 17:29:28 +0100
committerChristoffer Dall <christoffer.dall@linaro.org>2016-08-09 16:43:23 +0200
commitfd837b08d98c0c9f4f31998f2ed55b9d8694082c (patch)
treec589233e641273319c4dd8248ce54e6c1d4fb526 /virt
parent29b4817d4018df78086157ea3a55c1d9424a7cfc (diff)
downloadlinux-stericsson-fd837b08d98c0c9f4f31998f2ed55b9d8694082c.tar.gz
KVM: arm64: ITS: return 1 on successful MSI injection
According to the KVM API documentation a successful MSI injection should return a value > 0 on success. Return possible errors in vgic_its_trigger_msi() and report a successful injection back to userland, while also reporting the case where the MSI could not be delivered due to the guest not having the LPI mapped, for instance. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/arm/vgic/vgic-its.c56
1 files changed, 37 insertions, 19 deletions
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 07411cf967b9..1bd8adbeae26 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -441,39 +441,48 @@ static unsigned long vgic_mmio_read_its_idregs(struct kvm *kvm,
* 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 void vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its,
- u32 devid, u32 eventid)
+static int vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its,
+ u32 devid, u32 eventid)
{
+ struct kvm_vcpu *vcpu;
struct its_itte *itte;
if (!its->enabled)
- return;
+ return -EBUSY;
itte = find_itte(its, devid, eventid);
- /* Triggering an unmapped IRQ gets silently dropped. */
- if (itte && its_is_collection_mapped(itte->collection)) {
- struct kvm_vcpu *vcpu;
-
- vcpu = kvm_get_vcpu(kvm, itte->collection->target_addr);
- if (vcpu && vcpu->arch.vgic_cpu.lpis_enabled) {
- spin_lock(&itte->irq->irq_lock);
- itte->irq->pending = true;
- vgic_queue_irq_unlock(kvm, itte->irq);
- }
- }
+ if (!itte || !its_is_collection_mapped(itte->collection))
+ return E_ITS_INT_UNMAPPED_INTERRUPT;
+
+ vcpu = kvm_get_vcpu(kvm, itte->collection->target_addr);
+ if (!vcpu)
+ return E_ITS_INT_UNMAPPED_INTERRUPT;
+
+ if (!vcpu->arch.vgic_cpu.lpis_enabled)
+ return -EBUSY;
+
+ spin_lock(&itte->irq->irq_lock);
+ itte->irq->pending = true;
+ vgic_queue_irq_unlock(kvm, itte->irq);
+
+ return 0;
}
/*
* Queries the KVM IO bus framework to get the ITS pointer from the given
* doorbell address.
* We then call vgic_its_trigger_msi() with the decoded data.
+ * According to the KVM_SIGNAL_MSI API description returns 1 on success.
*/
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;
+ int ret;
if (!vgic_has_its(kvm))
return -ENODEV;
@@ -490,10 +499,21 @@ int vgic_its_inject_msi(struct kvm *kvm, struct kvm_msi *msi)
iodev = container_of(kvm_io_dev, struct vgic_io_device, dev);
mutex_lock(&iodev->its->its_lock);
- vgic_its_trigger_msi(kvm, iodev->its, msi->devid, msi->data);
+ ret = vgic_its_trigger_msi(kvm, iodev->its, msi->devid, msi->data);
mutex_unlock(&iodev->its->its_lock);
- return 0;
+ if (ret < 0)
+ return ret;
+
+ /*
+ * KVM_SIGNAL_MSI demands a return value > 0 for success and 0
+ * if the guest has blocked the MSI. So we map any LPI mapping
+ * related error to that.
+ */
+ if (ret)
+ return 0;
+ else
+ return 1;
}
/* Requires the its_lock to be held. */
@@ -981,9 +1001,7 @@ static int vgic_its_cmd_handle_int(struct kvm *kvm, struct vgic_its *its,
u32 msi_data = its_cmd_get_id(its_cmd);
u64 msi_devid = its_cmd_get_deviceid(its_cmd);
- vgic_its_trigger_msi(kvm, its, msi_devid, msi_data);
-
- return 0;
+ return vgic_its_trigger_msi(kvm, its, msi_devid, msi_data);
}
/*