From mboxrd@z Thu Jan  1 00:00:00 1970
From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Subject: Re: [PATCH 2/4] sysctl/libxl: Add interface for
 returning IO topology data
Date: Wed, 03 Dec 2014 10:37:59 -0500
Message-ID: <547F2E57.7010300@oracle.com>
References: <1417556050-23364-1-git-send-email-boris.ostrovsky@oracle.com>
	<1417556050-23364-3-git-send-email-boris.ostrovsky@oracle.com>
	<547F2A5B.9060407@citrix.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"; Format="flowed"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
In-Reply-To: <547F2A5B.9060407@citrix.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: Andrew Cooper <andrew.cooper3@citrix.com>, jbeulich@suse.com, keir@xen.org, ian.jackson@eu.citrix.com, stefano.stabellini@eu.citrix.com, ian.campbell@citrix.com, wei.liu2@citrix.com
Cc: dario.faggioli@citrix.com, ufimtseva@gmail.com, xen-devel@lists.xen.org
List-Id: xen-devel@lists.xenproject.org

On 12/03/2014 10:20 AM, Andrew Cooper wrote:
> On 02/12/14 21:34, Boris Ostrovsky wrote:
>>   /* XEN_SYSCTL_topologyinfo */
>>   #define INVALID_TOPOLOGY_ID  (~0U)
>> +
>> +struct xen_sysctl_cputopo {
>> +    uint32_t core;
>> +    uint32_t socket;
>> +    uint32_t node;
>> +};
>> +typedef struct xen_sysctl_cputopo xen_sysctl_cputopo_t;
>> +DEFINE_XEN_GUEST_HANDLE(xen_sysctl_cputopo_t);
>> +
>> +struct xen_sysctl_iotopo {
>> +    uint16_t seg;
>> +    uint8_t bus;
>> +    uint8_t devfn;
>> +    uint32_t node;
>> +};
>> +typedef struct xen_sysctl_iotopo xen_sysctl_iotopo_t;
>> +DEFINE_XEN_GUEST_HANDLE(xen_sysctl_iotopo_t);
>> +
>>   struct xen_sysctl_topologyinfo {
>>       /*
>>        * IN: maximum addressable entry in the caller-provided arrays.
>> -     * OUT: largest cpu identifier in the system.
>> +     * OUT: largest cpu identifier or max number of devices in the system.
>>        * If OUT is greater than IN then the arrays are truncated!
>>        * If OUT is leass than IN then the array tails are not written by sysctl.
>>        */
>>       uint32_t max_cpu_index;
>> +    uint32_t max_devs;
>>   
>>       /*
>>        * If not NULL, these arrays are filled with core/socket/node identifier
>> -     * for each cpu.
>> -     * If a cpu has no core/socket/node information (e.g., cpu not present)
>> -     * then the sentinel value ~0u is written to each array.
>> -     * The number of array elements written by the sysctl is:
>> +     * for each cpu and/or node for each PCI device.
>> +     * If information for a particular entry is not avalable it is set to
>> +     * INVALID_TOPOLOGY_ID.
>> +     * The number of array elements for CPU topology written by the sysctl is:
>>        *   min(@max_cpu_index_IN,@max_cpu_index_OUT)+1
>>        */
>> -    XEN_GUEST_HANDLE_64(uint32) cpu_to_core;
>> -    XEN_GUEST_HANDLE_64(uint32) cpu_to_socket;
>> -    XEN_GUEST_HANDLE_64(uint32) cpu_to_node;
>> +    XEN_GUEST_HANDLE_64(xen_sysctl_cputopo_t) cputopo;
>> +    XEN_GUEST_HANDLE_64(xen_sysctl_iotopo_t) iotopo;
> These are inherently lists with different indicies.  They should not
> conglomerated like this.


I don't follow this. These are indeed lists with different indicies but 
why can't they both be part of this struct?

-boris

>
> I would suggest introducing a new hypercall (xen_sysctl_iotopologyinfo
> ?) and leave this one alone.
>
> ~Andrew