From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: [PATCH 04/11] x86/MM: Improve p2m type checks.
Date: Mon, 12 Jan 2015 17:48:22 +0000
Message-ID: <54B408E6.8060404@citrix.com>
References: <1420838801-11704-1-git-send-email-edmund.h.white@intel.com>
	<1420838801-11704-5-git-send-email-edmund.h.white@intel.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
In-Reply-To: <1420838801-11704-5-git-send-email-edmund.h.white@intel.com>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: Ed White <edmund.h.white@intel.com>, xen-devel@lists.xen.org
Cc: ian.jackson@eu.citrix.com, tim@xen.org, keir@xen.org, ian.campbell@citrix.com, jbeulich@suse.com
List-Id: xen-devel@lists.xenproject.org

On 09/01/15 21:26, Ed White wrote:
> diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
> index 5f7fe71..8193901 100644
> --- a/xen/include/asm-x86/p2m.h
> +++ b/xen/include/asm-x86/p2m.h
> @@ -193,6 +193,9 @@ struct p2m_domain {
>       * threaded on in LRU order. */
>      struct list_head   np2m_list;
>  
> +    /* Does this p2m belong to the altp2m code? */
> +    bool_t alternate;
> +
>      /* Host p2m: Log-dirty ranges registered for the domain. */
>      struct rangeset   *logdirty_ranges;
>  
> @@ -290,7 +293,9 @@ struct p2m_domain *p2m_get_nestedp2m(struct vcpu *v, uint64_t np2m_base);
>   */
>  struct p2m_domain *p2m_get_p2m(struct vcpu *v);
>  
> -#define p2m_is_nestedp2m(p2m)   ((p2m) != p2m_get_hostp2m((p2m->domain)))
> +#define p2m_is_hostp2m(p2m)   ((p2m) == p2m_get_hostp2m((p2m->domain)))
> +#define p2m_is_altp2m(p2m)    ((p2m)->alternate)
> +#define p2m_is_nestedp2m(p2m) (!p2m_is_altp2m(p2m) && !p2m_ishostp2m(p2m))

Might this be better expressed as a p2m type, currently of the set
{host, alt, nested} ?  p2m_is_nestedp2m() is starting to hide some
moderately complicated calculations.

~Andrew