[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v5 00/12] SVE feature for arm guests
- To: Luca Fancellu <Luca.Fancellu@xxxxxxx>
- From: Bertrand Marquis <Bertrand.Marquis@xxxxxxx>
- Date: Tue, 18 Apr 2023 15:00:28 +0000
- Accept-language: en-GB, en-US
- Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=arm.com; dmarc=pass action=none header.from=arm.com; dkim=pass header.d=arm.com; arc=none
- Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=/4sNW1PuzWecqMdLwH/QY3oViqeHefFf+DMTDFaJ+Z0=; b=WiW4lGkxvFk2pMLEyYR+syiW6Ws1Fh7XbVMG2vecmKZ6u7RO5SnA+Pk5FLtWXuWsa9nvKgenXE/+Ek86Lm3aXRVhlG8A08n26D2m8mUYZGx6XGvR1q2RfjZuO1lUER4hkXaiZDWkd4NoT2I3RW4UvHTcjeBGHG0eaAG/xWPScQ7eTEfamII5Bx+C/TkZIzSywXtNuXa6J0B3HW7ojPg++gG8fnuj3FHb7JfGmPRBcQFqlDitrtbACR2K7oZEhwuzDdUufhbrGZweA96VogSwUHPCRsQvqNnSxGHEBa5YZevpo2M4P+D7jpnEXEPuDaw5Q/x1yL1o2Z7/B5f0Oa4GPA==
- Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=Ma5y3N//Ruk0h4bk85FH3EBoDj9uxbu768xMtz2yET1z59MLn9Cf0HFMxwHRXxF2n1OXaTSoDWWouC/JreG4SzjwVA+t02yyNlH/fnakzlkiSB2kJLdL3MCN9NTpjRMeO6Zw+StqWDUKXeaWeQcvGa7m1lyV1fVhhdxetqhARhVgg6FrkS9yZ3e37cgLhydVxGjK0gbwzpvO3ROJyFVERB5nmdH/FCrhX2939rnRU4lE7m/aD4sPYI3BoJ3/C/p4ZH5icnDU3i8YGKA/2CLs+24M0MQyjddlmes7skbotGtZF1r9ZGaS6LFCD7M6y29i6VdGlZX1SwXbNrUERHAw5Q==
- Authentication-results-original: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=arm.com;
- Cc: Julien Grall <julien@xxxxxxx>, Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>, Wei Chen <Wei.Chen@xxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>, Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, George Dunlap <george.dunlap@xxxxxxxxxx>, Jan Beulich <jbeulich@xxxxxxxx>, Wei Liu <wl@xxxxxxx>, Roger Pau Monné <roger.pau@xxxxxxxxxx>, Nick Rosbrook <rosbrookn@xxxxxxxxx>, Anthony PERARD <anthony.perard@xxxxxxxxxx>, Juergen Gross <jgross@xxxxxxxx>, Christian Lindig <christian.lindig@xxxxxxxxxx>, David Scott <dave@xxxxxxxxxx>, Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>, Henry Wang <Henry.Wang@xxxxxxx>, Community Manager <community.manager@xxxxxxxxxxxxxx>
- Delivery-date: Tue, 18 Apr 2023 15:01:28 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
- Nodisclaimer: true
- Original-authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=arm.com;
- Thread-index: AQHZbSQqKlfgrZX3xkqta7+H+1gq3K8xFMoAgAAUHYCAAAOtgIAAAMGAgAAFWgA=
- Thread-topic: [PATCH v5 00/12] SVE feature for arm guests
Hi Luca,
> On 18 Apr 2023, at 16:41, Luca Fancellu <Luca.Fancellu@xxxxxxx> wrote:
>
>
>
>> On 18 Apr 2023, at 15:38, Bertrand Marquis <Bertrand.Marquis@xxxxxxx> wrote:
>>
>> Hi Julien,
>>
>>> On 18 Apr 2023, at 16:25, Julien Grall <julien@xxxxxxx> wrote:
>>>
>>>
>>>
>>> On 18/04/2023 14:13, Bertrand Marquis wrote:
>>>> Hi Luca,
>>>
>>> Hi,
>>>
>>>> On this serie I would like to open a discussion on how to handle the
>>>> vector size
>>>> and the corresponding command line / configuration / device tree
>>>> parameters.
>>>> In general the user must either give a vector size it wants or has a
>>>> solution to
>>>> just request the maximum supported size.
>>>> In the current implementation if a size bigger than the supported one is
>>>> provided:
>>>> - we silently disable SVE for dom0
>>>> - we silently disable SVE for dom0less
>>>> - we do not create a guest when done through tools
>>>> This is not completely coherent and i think we should aim for a coherent
>>>> behaviour
>>>> unless we have arguments for this status.
>>>
>>> +1.
>>>
>>>> Is there any good reason to silently disable for Dom0 and dom0less only ?
>>>> I see some possible solutions here:
>>>> - modify parameter behaviour to use the supported size if parameter is
>>>> bigger than
>>>> it. This would at least keep SVE enabled if a VM depends on it and could
>>>> simplify
>>>> some of the handling by using 2048 to use the maximum supported size.
>>>
>>> My concern with this approach and the third one is the user may take some
>>> time to realize the problem in the xl.cfg. So...
>>
>> Good point
>>
>>>
>>>> - coherently stop if the parameter value is not supported (including if
>>>> sve is
>>>> not supported)
>>>
>>> ... this is my preferred approach because it would be clear that the value
>>> passed to Xen is bogus.
>>
>> I agree: we should not silently ignore configuration parameters or try to
>> "fix" them.
>
> Hi Bertrand and Julien,
>
> Ok I will update the serie to stop the domain creation if the parameter
> supplied is wrong or SVE is not supported by the platform.
Thanks
Bertrand
>
>>
>> Cheers
>> Bertrand
|
