From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Chen, Tiejun" <tiejun.chen@intel.com>
Subject: Re: [v8][PATCH 07/17] hvmloader/util: get reserved
 device memory maps
Date: Mon, 08 Dec 2014 16:45:36 +0800
Message-ID: <54856530.7050206@intel.com>
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To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: kevin.tian@intel.com, wei.liu2@citrix.com, ian.campbell@citrix.com, stefano.stabellini@eu.citrix.com, tim@xen.org, ian.jackson@eu.citrix.com, xen-devel@lists.xen.org, jbeulich@suse.com, yang.z.zhang@intel.com
List-Id: xen-devel@lists.xenproject.org

On 2014/12/8 16:09, Chen, Tiejun wrote:
> On 2014/12/3 4:01, Konrad Rzeszutek Wilk wrote:
>> On Mon, Dec 01, 2014 at 05:24:25PM +0800, Tiejun Chen wrote:
>>> We need to use reserved device memory maps with multiple times, so
>>> provide just one common function should be friend.
>>
>> We need to call reserved device memory maps hypercall
>> (XENMEM_reserved_device_memory_map) many times, hence provide one
>> common function.
>
> Rephrased and thanks.
>
>>
>>>
>>> Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
>>> ---
>>>   tools/firmware/hvmloader/util.c | 59
>>> +++++++++++++++++++++++++++++++++++++++++
>>>   tools/firmware/hvmloader/util.h |  2 ++
>>>   2 files changed, 61 insertions(+)
>>>
>>> diff --git a/tools/firmware/hvmloader/util.c
>>> b/tools/firmware/hvmloader/util.c
>>> index 80d822f..dd81fb6 100644
>>> --- a/tools/firmware/hvmloader/util.c
>>> +++ b/tools/firmware/hvmloader/util.c
>>> @@ -22,11 +22,14 @@
>>>   #include "config.h"
>>>   #include "hypercall.h"
>>>   #include "ctype.h"
>>> +#include "errno.h"
>>>   #include <stdint.h>
>>>   #include <xen/xen.h>
>>>   #include <xen/memory.h>
>>>   #include <xen/sched.h>
>>>
>>> +struct xen_reserved_device_memory *rdm_map;
>>> +
>>>   void wrmsr(uint32_t idx, uint64_t v)
>>>   {
>>>       asm volatile (
>>> @@ -828,6 +831,62 @@ int hpet_exists(unsigned long hpet_base)
>>>       return ((hpet_id >> 16) == 0x8086);
>>>   }
>>>
>>> +static int
>>> +get_reserved_device_memory_map(struct xen_reserved_device_memory
>>> entries[],
>>> +                               uint32_t *max_entries)
>>> +{
>>> +    int rc;
>>> +    struct xen_reserved_device_memory_map xrdmmap = {
>>> +        .domid = DOMID_SELF,
>>> +        .nr_entries = *max_entries
>>> +    };
>>> +
>>> +    set_xen_guest_handle(xrdmmap.buffer, entries);
>>> +
>>> +    rc = hypercall_memory_op(XENMEM_reserved_device_memory_map,
>>> &xrdmmap);
>>> +    *max_entries = xrdmmap.nr_entries;
>>
>> Don't you want to check rc first before altering 'max_entries' ?
>
> -    *max_entries = xrdmmap.nr_entries;
> +    if ( rc == -ENOBUFS )
> +        *max_entries = xrdmmap.nr_entries;
>

Something remind me. That is, in all case we should set max_entries 
since now we don't count all RMRR ranges again. Instead, we may count 
those RMRR ranges associated to a assigned device but obviously, it may 
have no any RMRR. So we always should update max_entries as well.

Thanks
Tiejun

Thanks
Tiejun