Commit fd837b08 authored by Andre Przywara's avatar Andre Przywara Committed by Christoffer Dall

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: default avatarAndre Przywara <andre.przywara@arm.com>
Reviewed-by: default avatarEric Auger <eric.auger@redhat.com>
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
parent 29b4817d
......@@ -337,6 +337,7 @@
*/
#define E_ITS_MOVI_UNMAPPED_INTERRUPT 0x010107
#define E_ITS_MOVI_UNMAPPED_COLLECTION 0x010109
#define E_ITS_INT_UNMAPPED_INTERRUPT 0x010307
#define E_ITS_CLEAR_UNMAPPED_INTERRUPT 0x010507
#define E_ITS_MAPD_DEVICE_OOR 0x010801
#define E_ITS_MAPC_PROCNUM_OOR 0x010902
......
......@@ -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);
}
/*
......
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