From mboxrd@z Thu Jan  1 00:00:00 1970
From: Julien Grall <julien.grall@linaro.org>
Subject: Re: [PATCH 1/2] gnttab: Introduce rwlock to protect
 updates to grant table state
Date: Tue, 02 Dec 2014 13:08:12 +0000
Message-ID: <547DB9BC.4040800@linaro.org>
References: <1417514784-15749-1-git-send-email-chegger@amazon.de>
	<1417514784-15749-2-git-send-email-chegger@amazon.de>
	<547DB21A.3090009@linaro.org> <547DB893.9020605@amazon.de>
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To: "Egger, Christoph" <chegger@amazon.de>, xen-devel@lists.xen.org
Cc: Keir Fraser <keir@xen.org>, Matt Wilson <msw@amazon.com>, Jan Beulich <jbeulich@suse.com>
List-Id: xen-devel@lists.xenproject.org

Hi,

On 02/12/14 13:03, Egger, Christoph wrote:
> On 2014/12/02 13:35, Julien Grall wrote:
>> Hi Christoph,
>>
>> On 02/12/14 10:06, Christoph Egger wrote:
>>> diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
>>> index 522c43d..37c13b1 100644
>>> --- a/xen/arch/x86/mm.c
>>> +++ b/xen/arch/x86/mm.c
>>> @@ -4565,7 +4565,7 @@ int xenmem_add_to_physmap_one(
>>>                  mfn = virt_to_mfn(d->shared_info);
>>>              break;
>>>          case XENMAPSPACE_grant_table:
>>> -            spin_lock(&d->grant_table->lock);
>>> +            write_lock(&d->grant_table->lock);
>>>  
>>>              if ( d->grant_table->gt_version == 0 )
>>>                  d->grant_table->gt_version = 1;
>>> @@ -4587,7 +4587,7 @@ int xenmem_add_to_physmap_one(
>>>                      mfn = virt_to_mfn(d->grant_table->shared_raw[idx]);
>>>              }
>>>  
>>> -            spin_unlock(&d->grant_table->lock);
>>> +            write_unlock(&d->grant_table->lock);
>>>              break;
>>>          case XENMAPSPACE_gmfn_range:
>>>          case XENMAPSPACE_gmfn:
>>
>> You forgot to modify the ARM bits which is using the spinlock. See
>> arch/arm/mm.c
> 
> I can do the change. But I don't have ARM hardware nor the build
> infrastructure. I need your help with compiling and testing on/for ARM.
> Alternatively you can send me a patch I can add to or squash into my
> patch series.

I agree that testing the ARM part may require a bit of setup. But
you can easily build testing. only a cross-compiler for ARM is required
for this step. See:

http://wiki.xen.org/wiki/Xen_ARM_with_Virtualization_Extensions#Building_Xen_on_ARM

Regards,

-- 
Julien Grall