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Date:   Mon, 16 May 2022 14:57:56 -0400
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Subject: Re: [PATCH V2 2/7] xen/grants: support allocating consecutive grants
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To:     Oleksandr <olekstysh@gmail.com>
Cc:     Juergen Gross <jgross@suse.com>, xen-devel@lists.xenproject.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Stefano Stabellini <sstabellini@kernel.org>,
        Julien Grall <julien@xen.org>,
        Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Christoph Hellwig <hch@infradead.org>
References: <1651947548-4055-1-git-send-email-olekstysh@gmail.com>
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From:   Boris Ostrovsky <boris.ostrovsky@oracle.com>
In-Reply-To: <b2d22549-cdde-1e52-18fd-0ff923b86a5d@gmail.com>
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On 5/16/22 2:30 PM, Oleksandr wrote:
>
> On 16.05.22 19:00, Boris Ostrovsky wrote:
>
>
>>
>>
>> With the error handling in gnttab_init() fixed
>
> yes, this is a diff that I am going to apply for the next version:
>
>
> [snip]
>
> @@ -1596,19 +1601,20 @@ static int gnttab_expand(unsigned int req_entries)
>  int gnttab_init(void)
>  {
>         int i;
> -       unsigned long max_nr_grant_frames;
> +       unsigned long max_nr_grant_frames, max_nr_grefs;
>         unsigned int max_nr_glist_frames, nr_glist_frames;
>         int ret;
>
>         gnttab_request_version();
>         max_nr_grant_frames = gnttab_max_grant_frames();
> +       max_nr_grefs = max_nr_grant_frames *
> + gnttab_interface->grefs_per_grant_frame;
>         nr_grant_frames = 1;
>
>         /* Determine the maximum number of frames required for the
>          * grant reference free list on the current hypervisor.
>          */
> -       max_nr_glist_frames = (max_nr_grant_frames *
> - gnttab_interface->grefs_per_grant_frame / RPP);
> +       max_nr_glist_frames = max_nr_grefs / RPP;
>
>         gnttab_list = kmalloc_array(max_nr_glist_frames,
>                                     sizeof(grant_ref_t *),
> @@ -1625,8 +1631,7 @@ int gnttab_init(void)
>                 }
>         }
>
> -       i = gnttab_interface->grefs_per_grant_frame * max_nr_grant_frames;
> -       gnttab_free_bitmap = bitmap_zalloc(i, GFP_KERNEL);
> +       gnttab_free_bitmap = bitmap_zalloc(max_nr_grefs, GFP_KERNEL);
>         if (!gnttab_free_bitmap) {
>                 ret = -ENOMEM;
>                 goto ini_nomem;
>


Looks good, thanks.


-boris