[PULL 24/37] KVM: arm64: vgic-its: ITT save and restore

Christoffer Dall
2017-05-09T10:42:25Z

Implement routines to save and restore device ITT and their
interrupt table entries (ITE).

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
---
virt/kvm/arm/vgic/vgic-its.c | 116 +++++++++++++++++++++++++++++++++++++++++--
virt/kvm/arm/vgic/vgic.h | 4 ++
2 files changed, 117 insertions(+), 3 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 3dea626..adb3d9e 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -1750,7 +1750,7 @@ static u32 compute_next_devid_offset(struct list_head *h,
return min_t(u32, next_offset, VITS_DTE_MAX_DEVID_OFFSET);
}

-u32 compute_next_eventid_offset(struct list_head *h, struct its_ite *ite)
+static u32 compute_next_eventid_offset(struct list_head *h, struct its_ite *ite)
{
struct its_ite *next;
u32 next_offset;
@@ -1827,14 +1827,124 @@ static int scan_its_table(struct vgic_its *its, gpa_t base, int size, int esz,
return ret;
}

+/**
+ * vgic_its_save_ite - Save an interrupt translation entry at @gpa
+ */
+static int vgic_its_save_ite(struct vgic_its *its, struct its_device *dev,
+ struct its_ite *ite, gpa_t gpa, int ite_esz)
+{
+ struct kvm *kvm = its->dev->kvm;
+ u32 next_offset;
+ u64 val;
+
+ next_offset = compute_next_eventid_offset(&dev->itt_head, ite);
+ val = ((u64)next_offset << KVM_ITS_ITE_NEXT_SHIFT) |
+ ((u64)ite->lpi << KVM_ITS_ITE_PINTID_SHIFT) |
+ ite->collection->collection_id;
+ val = cpu_to_le64(val);
+ return kvm_write_guest(kvm, gpa, &val, ite_esz);
+}
+
+/**
+ * vgic_its_restore_ite - restore an interrupt translation entry
+ * @event_id: id used for indexing
+ * @ptr: pointer to the ITE entry
+ * @opaque: pointer to the its_device
+ */
+static int vgic_its_restore_ite(struct vgic_its *its, u32 event_id,
+ void *ptr, void *opaque)
+{
+ struct its_device *dev = (struct its_device *)opaque;
+ struct its_collection *collection;
+ struct kvm *kvm = its->dev->kvm;
+ struct kvm_vcpu *vcpu = NULL;
+ u64 val;
+ u64 *p = (u64 *)ptr;
+ struct vgic_irq *irq;
+ u32 coll_id, lpi_id;
+ struct its_ite *ite;
+ u32 offset;
+
+ val = *p;
+
+ val = le64_to_cpu(val);
+
+ coll_id = val & KVM_ITS_ITE_ICID_MASK;
+ lpi_id = (val & KVM_ITS_ITE_PINTID_MASK) >> KVM_ITS_ITE_PINTID_SHIFT;
+
+ if (!lpi_id)
+ return 1; /* invalid entry, no choice but to scan next entry */
+
+ if (lpi_id < VGIC_MIN_LPI)
+ return -EINVAL;
+
+ offset = val >> KVM_ITS_ITE_NEXT_SHIFT;
+ if (event_id + offset >= BIT_ULL(dev->num_eventid_bits))
+ return -EINVAL;
+
+ collection = find_collection(its, coll_id);
+ if (!collection)
+ return -EINVAL;
+
+ ite = vgic_its_alloc_ite(dev, collection, lpi_id, event_id);
+ if (IS_ERR(ite))
+ return PTR_ERR(ite);
+
+ if (its_is_collection_mapped(collection))
+ vcpu = kvm_get_vcpu(kvm, collection->target_addr);
+
+ irq = vgic_add_lpi(kvm, lpi_id, vcpu);
+ if (IS_ERR(irq))
+ return PTR_ERR(irq);
+ ite->irq = irq;
+
+ return offset;
+}
+
+static int vgic_its_ite_cmp(void *priv, struct list_head *a,
+ struct list_head *b)
+{
+ struct its_ite *itea = container_of(a, struct its_ite, ite_list);
+ struct its_ite *iteb = container_of(b, struct its_ite, ite_list);
+
+ if (itea->event_id < iteb->event_id)
+ return -1;
+ else
+ return 1;
+}
+
static int vgic_its_save_itt(struct vgic_its *its, struct its_device *device)
{
- return -ENXIO;
+ const struct vgic_its_abi *abi = vgic_its_get_abi(its);
+ gpa_t base = device->itt_addr;
+ struct its_ite *ite;
+ int ret;
+ int ite_esz = abi->ite_esz;
+
+ list_sort(NULL, &device->itt_head, vgic_its_ite_cmp);
+
+ list_for_each_entry(ite, &device->itt_head, ite_list) {
+ gpa_t gpa = base + ite->event_id * ite_esz;
+
+ ret = vgic_its_save_ite(its, device, ite, gpa, ite_esz);
+ if (ret)
+ return ret;
+ }
+ return 0;
}

static int vgic_its_restore_itt(struct vgic_its *its, struct its_device *dev)
{
- return -ENXIO;
+ const struct vgic_its_abi *abi = vgic_its_get_abi(its);
+ gpa_t base = dev->itt_addr;
+ int ret;
+ int ite_esz = abi->ite_esz;
+ size_t max_size = BIT_ULL(dev->num_eventid_bits) * ite_esz;
+
+ ret = scan_its_table(its, base, max_size, ite_esz, 0,
+ vgic_its_restore_ite, dev);
+
+ return ret;
}

/**
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index f35e993..433449b 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -81,6 +81,10 @@
#define KVM_ITS_CTE_VALID_MASK BIT_ULL(63)
#define KVM_ITS_CTE_RDBASE_SHIFT 16
#define KVM_ITS_CTE_ICID_MASK GENMASK_ULL(15, 0)
+#define KVM_ITS_ITE_NEXT_SHIFT 48
+#define KVM_ITS_ITE_PINTID_SHIFT 16
+#define KVM_ITS_ITE_PINTID_MASK GENMASK_ULL(47, 16)
+#define KVM_ITS_ITE_ICID_MASK GENMASK_ULL(15, 0)
#define KVM_ITS_DTE_VALID_SHIFT 63
#define KVM_ITS_DTE_VALID_MASK BIT_ULL(63)
#define KVM_ITS_DTE_NEXT_SHIFT 49
--
2.9.0