[PATCH v3 17/19] KVM: arm64: ITS: ITT flush and restore
From: andre.przywara@arm.com (Andre Przywara)
Date: 2017-03-21 18:13:43
Also in:
kvm, kvmarm
Hi, On 06/03/17 11:34, Eric Auger wrote:
quoted hunk ↗ jump to hunk
Introduce routines to flush and restore device ITT and their interrupt table entries (ITE). The routines will be called on device table flush and restore. Signed-off-by: Eric Auger <eric.auger@redhat.com> --- v2 -> v3: - add return 0 in vgic_its_restore_ite (was in subsequent patch) v2: creation --- virt/kvm/arm/vgic/vgic-its.c | 100 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 100 insertions(+)diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index 1060125..a216849 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c@@ -1748,6 +1748,106 @@ static int vgic_its_restore_pending_tables(struct vgic_its *its) return -ENXIO; } +static int vgic_its_flush_ite(struct vgic_its *its, struct its_device *dev, + struct its_ite *ite, gpa_t gpa) +{ + 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 << 48) | ((u64)ite->lpi << 16) | + ite->collection->collection_id; + val = cpu_to_le64(val); + return kvm_write_guest(kvm, gpa, &val, VITS_ESZ); +} + +/** + * vgic_its_restore_ite - restore an interrupt translation entry + * @event_id: id used for indexing + * @ptr: kernel VA where the 8 byte ITE is located + * @opaque: pointer to the its_device + * @next: id offset to the next entry + */ +static int vgic_its_restore_ite(struct vgic_its *its, u32 event_id, + void *ptr, void *opaque, u32 *next) +{ + struct its_device *dev = (struct its_device *)opaque; + struct its_collection *collection; + struct kvm *kvm = its->dev->kvm; + u64 val, *p = (u64 *)ptr; + struct vgic_irq *irq; + u32 coll_id, lpi_id; + struct its_ite *ite; + int ret; + + val = *p; + *next = 1; + + val = le64_to_cpu(val); + + coll_id = val & GENMASK_ULL(15, 0); + lpi_id = (val & GENMASK_ULL(47, 16)) >> 16; + + if (!lpi_id) + return 0; + + *next = (val & GENMASK_ULL(63, 48)) >> 48;
No need for the mask here, just ">> 48" would be enough.
+
+ collection = find_collection(its, coll_id);
+ if (!collection)
+ return -EINVAL;
+
+ ret = vgic_its_alloc_ite(dev, &ite, collection,
+ lpi_id, event_id);
+ if (ret)
+ return ret;
+
+ irq = vgic_add_lpi(kvm, lpi_id);
+ if (IS_ERR(irq))
+ return PTR_ERR(irq);
+ ite->irq = irq;
+
+ /* restore the configuration of the LPI */
+ ret = update_lpi_config(kvm, irq, NULL);
+ if (ret)
+ return ret;
+
+ update_affinity_ite(kvm, ite);
+ return 0;
+}
+
+static int vgic_its_flush_itt(struct vgic_its *its, struct its_device *device)
+{
+ gpa_t base = device->itt_addr;
+ struct its_ite *ite;
+ int ret;
+
+ list_for_each_entry(ite, &device->itt_head, ite_list) {
+ gpa_t gpa = base + ite->event_id * VITS_ESZ;
+
+ ret = vgic_its_flush_ite(its, device, ite, gpa);
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
+static int vgic_its_restore_itt(struct vgic_its *its,
+ struct its_device *dev)
+{
+ size_t max_size = (2 << dev->nb_eventid_bits) * VITS_ESZ;I think that depends on your usage of nb_eventid_bits, but this "2 <<" is really confusing here. So I really think you should just hold the actual number of bits in this variable and handle the +/- 1 encoding just once when sourcing the information. The rest looks fine. Cheers, Andre.
+ gpa_t base = dev->itt_addr; + int ret; + + ret = lookup_table(its, base, max_size, VITS_ESZ, 0, + vgic_its_restore_ite, dev); + + if (ret < 0) + return ret; + return 0; +} + /** * vgic_its_flush_device_tables - flush the device table and all ITT * into guest RAM