linux-kernel - Re: [PATCH v1 06/29] virtio-mem: generalize virtio_mem_owned

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Date:   Thu, 15 Oct 2020 22:30:09 +0200
From:   Pankaj Gupta <pankaj.gupta.linux@...il.com>
To:     David Hildenbrand <david@...hat.com>
Cc:     LKML <linux-kernel@...r.kernel.org>, Linux MM <linux-mm@...ck.org>,
        virtualization@...ts.linux-foundation.org,
        Andrew Morton <akpm@...ux-foundation.org>,
        "Michael S . Tsirkin" <mst@...hat.com>,
        Jason Wang <jasowang@...hat.com>
Subject: Re: [PATCH v1 06/29] virtio-mem: generalize virtio_mem_owned_mb()

> Avoid using memory block ids. Rename it to virtio_mem_contains_range().
>
> Cc: "Michael S. Tsirkin" <mst@...hat.com>
> Cc: Jason Wang <jasowang@...hat.com>
> Cc: Pankaj Gupta <pankaj.gupta.linux@...il.com>
> Signed-off-by: David Hildenbrand <david@...hat.com>
> ---
>  drivers/virtio/virtio_mem.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
> index 6bbd1cfd10d3..821143db14fe 100644
> --- a/drivers/virtio/virtio_mem.c
> +++ b/drivers/virtio/virtio_mem.c
> @@ -500,12 +500,13 @@ static bool virtio_mem_overlaps_range(struct virtio_mem *vm,
>  }
>
>  /*
> - * Test if a virtio-mem device owns a memory block. Can be called from
> + * Test if a virtio-mem device contains a given range. Can be called from
>   * (notifier) callbacks lockless.
>   */
> -static bool virtio_mem_owned_mb(struct virtio_mem *vm, unsigned long mb_id)
> +static bool virtio_mem_contains_range(struct virtio_mem *vm, uint64_t start,
> +                                     uint64_t size)
>  {
> -       return mb_id >= vm->first_mb_id && mb_id <= vm->last_mb_id;
> +       return start >= vm->addr && start + size <= vm->addr + vm->region_size;
>  }
>
>  static int virtio_mem_notify_going_online(struct virtio_mem *vm,
> @@ -800,7 +801,7 @@ static void virtio_mem_online_page_cb(struct page *page, unsigned int order)
>          */
>         rcu_read_lock();
>         list_for_each_entry_rcu(vm, &virtio_mem_devices, next) {
> -               if (!virtio_mem_owned_mb(vm, mb_id))
> +               if (!virtio_mem_contains_range(vm, addr, PFN_PHYS(1 << order)))
>                         continue;
>
>                 sb_id = virtio_mem_phys_to_sb_id(vm, addr);

Looks good.
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@...il.com>