Hi,
On 06/03/17 11:34, Eric Auger wrote:
> 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@xxxxxxxxxx>
>
> ---
>
> 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.
> + 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;
> }
>
> /**
>
