[PATCH v3 15/19] KVM: arm64: ITS: Collection table save/restore
From: andre.przywara@arm.com (Andre Przywara)
Date: 2017-03-21 18:13:09
Also in:
kvm, kvmarm
Hi, On 06/03/17 11:34, Eric Auger wrote:
quoted hunk ↗ jump to hunk
The flush path copies the collection entries into guest RAM at the GPA specified in the BASER register. This obviously requires the BASER to be set. The last written element is a dummy collection table entry. We do not index by collection ID as the collection entry can fit into 8 bytes while containing the collection ID. On restore path we re-allocate the collection objects. Signed-off-by: Eric Auger <eric.auger@redhat.com> --- v1 -> v2: - reword commit message and directly use 8 as entry size - no kvm parameter anymore - add helper for flush/restore cte - table size computed here - add le64/cpu conversions --- virt/kvm/arm/vgic/vgic-its.c | 94 +++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 92 insertions(+), 2 deletions(-)diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index cf04776..ad67759 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c@@ -1761,13 +1761,84 @@ static int vgic_its_restore_device_tables(struct vgic_its *its) return -ENXIO; } +static int vgic_its_flush_cte(struct vgic_its *its, + struct its_collection *collection, u64 *ptr)
I don't think "u64 *ptr" is right here, why not use "gpa_t gpa" and save the cast below?
+{
+ u64 val;
+ int ret;
+
+ val = ((u64)1 << 63 | ((u64)collection->target_addr << 16) |
+ collection->collection_id);
+ val = cpu_to_le64(val);
+ ret = kvm_write_guest(its->dev->kvm, (gpa_t)ptr, &val, 8);
+ return ret;
+}
+
+static int vgic_its_restore_cte(struct vgic_its *its, u64 *ptr, bool *valid)
+{
+ struct its_collection *collection;
+ u32 target_addr;
+ u32 coll_id;
+ u64 val;
+ int ret;
+
+ *valid = false;
+
+ ret = kvm_read_guest(its->dev->kvm, (gpa_t)ptr, &val, 8);
+ if (ret)
+ return ret;
+ val = le64_to_cpu(val);
+ *valid = val & BIT_ULL(63);
+
+ if (!*valid)
+ return 0;
+
+ target_addr = (u32)(val >> 16);
+ coll_id = val & 0xFFFF;
+ ret = vgic_its_alloc_collection(its, &collection, coll_id);I think you should do as the other users do and check if there is a collection with that ID already. Or refactor vgic_its_alloc_collection() to do that for you: allocate or use an existing one.
+ if (ret)
+ return ret;
+ collection->target_addr = target_addr;
+ return 0;
+}
+
/**
* vgic_its_flush_collection_table - flush the collection table into
* guest RAM
*/
static int vgic_its_flush_collection_table(struct vgic_its *its)
{
- return -ENXIO;
+ struct its_collection *collection;
+ u64 val, *ptr;Please don't use a pointer for that guest address, use gpa_t instead.
quoted hunk ↗ jump to hunk
+ size_t max_size, filled = 0; + int ret; + + ptr = (u64 *)(BASER_ADDRESS(its->baser_coll_table)); + if (!ptr) + return 0; + + max_size = GITS_BASER_NR_PAGES(its->baser_coll_table) * SZ_64K; + + list_for_each_entry(collection, &its->collection_list, coll_list) { + if (filled == max_size) + return -ENOSPC; + ret = vgic_its_flush_cte(its, collection, ptr); + if (ret) + return ret; + ptr++; + filled += 8; + } + + if (filled == max_size) + return 0; + + /* + * table is not fully filled, add a last dummy element + * with valid bit unset + */ + val = 0; + ret = kvm_write_guest(its->dev->kvm, (gpa_t)ptr, &val, 8); + return ret; } /**@@ -1777,7 +1848,26 @@ static int vgic_its_flush_collection_table(struct vgic_its *its) */ static int vgic_its_restore_collection_table(struct vgic_its *its) { - return -ENXIO; + size_t max_size, read = 0; + u64 *ptr;
Same comment as above, please use gpa_t. Cheers, Andre.
+ int ret;
+
+ ptr = (u64 *)(BASER_ADDRESS(its->baser_coll_table));
+ if (!ptr)
+ return 0;
+
+ max_size = GITS_BASER_NR_PAGES(its->baser_coll_table) * SZ_64K;
+
+ while (read < max_size) {
+ bool valid;
+
+ ret = vgic_its_restore_cte(its, ptr, &valid);
+ if (!valid || ret)
+ break;
+ ptr++;
+ read += 8;
+ }
+ return ret;
}
/**