Re: [Xen-devel] [RFC 21/22] xen/arm: p2m: Re-implement p2m_set_mem_access using p2m_{set, get}_entry

[Tamas K Lengyel <tamas@xxxxxxxxxxxxx>]

On Thu, Jul 28, 2016 at 8:51 AM, Julien Grall <julien.grall@xxxxxxx> wrote:
> The function p2m_set_mem_access can be re-implemented using the generic
> functions p2m_get_entry and __p2m_set_entry.
>
> Note that because of the implementation of p2m_get_entry, a TLB
> invalidation instruction will be issued for each 4KB page. Therefore the
> performance of memaccess will be impacted, however the function is now
> safe on all the processors.
>
> Also the function apply_p2m_changes is dropped completely as it is not
> unused anymore.

Typo, (not *used*).

[...]

> @@ -2069,6 +1780,7 @@ long p2m_set_mem_access(struct domain *d, gfn_t gfn, 
> uint32_t nr,
>  {
>      struct p2m_domain *p2m = p2m_get_hostp2m(d);
>      p2m_access_t a;
> +    unsigned int order;
>      long rc = 0;
>
>      static const p2m_access_t memaccess[] = {
> @@ -2111,8 +1823,43 @@ long p2m_set_mem_access(struct domain *d, gfn_t gfn, 
> uint32_t nr,
>          return 0;
>      }
>
> -    rc = apply_p2m_changes(d, MEMACCESS, gfn_add(gfn, start),
> -                           (nr - start), INVALID_MFN, mask, 0, a);
> +    p2m_write_lock(p2m);
> +
> +    for ( gfn = gfn_add(gfn, start); nr > start; gfn = gfn_add(gfn, 1UL << 
> order) )

Long line here (84 width).

Tamas

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