Re: [PATCH v5 15/22] KVM: arm64: vgic-its: vgic_its_alloc_ite/device

Christoffer Dall
2017-04-27T17:31:46Z

On Fri, Apr 14, 2017 at 12:15:27PM +0200, Eric Auger wrote:
> Add two new helpers to allocate an its ite and an its device.
> This will avoid duplication on restore path.
>
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
>
> ---
>
> v4 -> v5:
> - add Marc's A-b
>
> v3 -> v4:
> - fix allocation
> - add comment about its_lock mutex hold
>
> v1 -> v2:
> - report itt_size fix and remove ITE_SIZE
> - s/itte/ite/g
> ---
> virt/kvm/arm/vgic/vgic-its.c | 73 ++++++++++++++++++++++++++++++--------------
> 1 file changed, 50 insertions(+), 23 deletions(-)
>
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 55267ab..56c5123 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -742,6 +742,27 @@ static void vgic_its_free_collection(struct vgic_its *its, u32 coll_id)
> kfree(collection);
> }
>
> +/* Must be called with its_lock mutex held */
> +static int vgic_its_alloc_ite(struct its_device *device,
> + struct its_ite **itep,
> + struct its_collection *collection,
> + u32 lpi_id, u32 event_id)
> +{
> + struct its_ite *ite;
> +
> + ite = kzalloc(sizeof(*ite), GFP_KERNEL);
> + if (!ite)
> + return -ENOMEM;
> +
> + ite->event_id = event_id;
> + ite->collection = collection;
> + ite->lpi = lpi_id;
> +
> + list_add_tail(&ite->ite_list, &device->itt_head);
> + *itep = ite;
> + return 0;
> +}

This static function should just return a 'struct its_ite *itep' and on
error you can return ERR_PTR(-ENOMEM).

> +
> /*
> * The MAPTI and MAPI commands map LPIs to ITTEs.
> * Must be called with its_lock mutex held.
> @@ -755,7 +776,7 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
> struct its_ite *ite;
> struct its_device *device;
> struct its_collection *collection, *new_coll = NULL;
> - int lpi_nr;
> + int lpi_nr, ret;
> struct vgic_irq *irq;
>
> device = find_its_device(its, device_id);
> @@ -785,19 +806,13 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
> new_coll = collection;
> }
>
> - ite = kzalloc(sizeof(struct its_ite), GFP_KERNEL);
> - if (!ite) {
> + ret = vgic_its_alloc_ite(device, &ite, collection, lpi_nr, event_id);
> + if (ret) {
> if (new_coll)
> vgic_its_free_collection(its, coll_id);
> - return -ENOMEM;
> + return ret;
> }
>
> - ite->event_id = event_id;
> - list_add_tail(&ite->ite_list, &device->itt_head);
> -
> - ite->collection = collection;
> - ite->lpi = lpi_nr;
> -
> irq = vgic_add_lpi(kvm, lpi_nr);
> if (IS_ERR(irq)) {
> if (new_coll)
> @@ -836,6 +851,29 @@ static void vgic_its_unmap_device(struct kvm *kvm, struct its_device *device)
> kfree(device);
> }
>
> +/* Must be called with its_lock mutex held */
> +static int vgic_its_alloc_device(struct vgic_its *its,
> + struct its_device **devp,
> + u32 device_id, gpa_t itt_addr,
> + u8 nb_eventid_bits)
> +{
> + struct its_device *device;
> +
> + device = kzalloc(sizeof(*device), GFP_KERNEL);
> + if (!device)
> + return -ENOMEM;
> +
> + device->device_id = device_id;
> + device->itt_addr = itt_addr;
> + device->nb_eventid_bits = nb_eventid_bits;
> + INIT_LIST_HEAD(&device->itt_head);
> +
> + list_add_tail(&device->dev_list, &its->device_list);
> + *devp = device;
> +
> + return 0;
> +}

also here, return ERR_PTR

> +
> /*
> * MAPD maps or unmaps a device ID to Interrupt Translation Tables (ITTs).
> * Must be called with the its_lock mutex held.
> @@ -872,19 +910,8 @@ static int vgic_its_cmd_handle_mapd(struct kvm *kvm, struct vgic_its *its,
> if (!valid)
> return 0;
>
> - device = kzalloc(sizeof(struct its_device), GFP_KERNEL);
> - if (!device)
> - return -ENOMEM;
> -
> - device->device_id = device_id;
> - device->nb_eventid_bits = nb_eventid_bits;
> - device->itt_addr = itt_addr;
> -
> - INIT_LIST_HEAD(&device->itt_head);
> -
> - list_add_tail(&device->dev_list, &its->device_list);
> -
> - return 0;
> + return vgic_its_alloc_device(its, &device, device_id,
> + itt_addr, nb_eventid_bits);
> }
>
> /*
> --
> 2.5.5
>
Thanks,
-Christoffer