Re: [PATCH v5 12/22] KVM: arm64: vgic-its: Interpret MAPD ITT_addr field

Christoffer Dall
2017-04-27T16:43:59Z

On Fri, Apr 14, 2017 at 12:15:24PM +0200, Eric Auger wrote:
> Up to now the MAPD ITT_addr had been ignored. We will need it
> for save/restore. Let's record it in the its_device struct.
>
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>
> ---
> v4 -> v5:
> - its_cmd_get_ittaddr macro now returns the actual ITT GPA
>
> v3 -> v4:
> - in vgic_its_cmd_handle_mapd, itt_addr directly is shifted
> - correct ittaddr bitmask to support 48bit GPA
> ---
> virt/kvm/arm/vgic/vgic-its.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 0f3c8f3..757598d 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -106,6 +106,7 @@ struct its_device {
> /* the head for the list of ITTEs */
> struct list_head itt_head;
> u32 nb_eventid_bits;
> + gpa_t itt_addr;
> u32 device_id;
> };
>
> @@ -569,6 +570,7 @@ static u64 its_cmd_mask_field(u64 *its_cmd, int word, int shift, int size)
> #define its_cmd_get_id(cmd) its_cmd_mask_field(cmd, 1, 0, 32)
> #define its_cmd_get_physical_id(cmd) its_cmd_mask_field(cmd, 1, 32, 32)
> #define its_cmd_get_collection(cmd) its_cmd_mask_field(cmd, 2, 0, 16)
> +#define its_cmd_get_ittaddr(cmd) (its_cmd_mask_field(cmd, 2, 8, 47) << 8)

Why 47? The ITT_addr field is bits [51:8] unless I'm looking at
something wrong?

> #define its_cmd_get_target_addr(cmd) its_cmd_mask_field(cmd, 2, 16, 32)
> #define its_cmd_get_validbit(cmd) its_cmd_mask_field(cmd, 2, 63, 1)
>
> @@ -840,6 +842,7 @@ static int vgic_its_cmd_handle_mapd(struct kvm *kvm, struct vgic_its *its,
> u32 device_id = its_cmd_get_deviceid(its_cmd);
> bool valid = its_cmd_get_validbit(its_cmd);
> u8 nb_eventid_bits = its_cmd_get_size(its_cmd);
> + gpa_t itt_addr = its_cmd_get_ittaddr(its_cmd);
> struct its_device *device;
>
> if (!vgic_its_check_id(its, its->baser_device_table, device_id))
> @@ -871,6 +874,7 @@ static int vgic_its_cmd_handle_mapd(struct kvm *kvm, struct vgic_its *its,
>
> device->device_id = device_id;
> device->nb_eventid_bits = nb_eventid_bits;
> + device->itt_addr = itt_addr;
>
> INIT_LIST_HEAD(&device->itt_head);
>
> --
> 2.5.5
>

Thanks,
-Christoffer