Re: [Xen-devel] [PATCH v3 3/8] xen: delay allocation of grant table sub structures

[Wei Liu <wei.liu2@xxxxxxxxxx>]

On Wed, Sep 06, 2017 at 02:46:48PM +0200, Juergen Gross wrote:
> diff --git a/xen/common/domain.c b/xen/common/domain.c
> index 5aebcf265f..11eb1778a3 100644
> --- a/xen/common/domain.c
> +++ b/xen/common/domain.c
> @@ -363,6 +363,9 @@ struct domain *domain_create(domid_t domid, unsigned int 
> domcr_flags,
>              goto fail;
>          init_status |= INIT_gnttab;
>  
> +        if ( domid == 0 && grant_table_init(d) )
> +            goto fail;
> +
>          poolid = 0;
>  
>          err = -ENOMEM;
> @@ -998,7 +1001,8 @@ int __domain_pause_by_systemcontroller(struct domain *d,
>          prev = cmpxchg(&d->controller_pause_count, old, new);
>      } while ( prev != old );
>  
> -    pause_fn(d);
> +    if ( pause_fn )
> +        pause_fn(d);
>  
>      return 0;
>  }
> @@ -1006,6 +1010,7 @@ int __domain_pause_by_systemcontroller(struct domain *d,
>  int domain_unpause_by_systemcontroller(struct domain *d)
>  {
>      int old, new, prev = d->controller_pause_count;
> +    int ret;
>  
>      do
>      {
> @@ -1029,8 +1034,16 @@ int domain_unpause_by_systemcontroller(struct domain 
> *d)
>       * Creation is considered finished when the controller reference count
>       * first drops to 0.
>       */
> -    if ( new == 0 )
> +    if ( new == 0 && !d->creation_finished )
> +    {

ret can be defined locally here.

> +        ret = grant_table_init(d);
> +        if ( ret )
> +        {
> +            __domain_pause_by_systemcontroller(d, NULL);
> +            return ret;
> +        }
>          d->creation_finished = true;
> +    }
>  
>      domain_unpause(d);
>  
> diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c
> index 4520e36d90..29e7fa539b 100644
> --- a/xen/common/grant_table.c
> +++ b/xen/common/grant_table.c
> @@ -1655,6 +1655,78 @@ gnttab_unpopulate_status_frames(struct domain *d, 
> struct grant_table *gt)
>      gt->nr_status_frames = 0;
>  }
>  
> +int
> +grant_table_init(struct domain *d)
> +{
> +    struct grant_table *gt = d->grant_table;
> +    unsigned int i, j;
> +
> +    if ( gt->nr_grant_frames )
> +        return 0;
> +

EBUSY here? I think we should catch the cases when this is called
multiple times.

With those changed:

Reviewed-by: Wei Liu <wei.liu2@xxxxxxxxxx>

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel