[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Need help to debug Arm SMMU issue seen on guests with passthrough devices


  • To: Ayan Kumar Halder <ayan.kumar.halder@xxxxxxxxxx>
  • From: Rahul Singh <Rahul.Singh@xxxxxxx>
  • Date: Thu, 21 Apr 2022 16:54:49 +0000
  • Accept-language: 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=eHRpoSgnui5pu95/h9IpUp2du+0058QGwq+wflPXLNY=; b=FYbm5VV6Zlu5w1l3g4WLf57e9IwbuHjmgSpxsp2FRuIDtGw03AS1G9SH6IuGPWOvjpo+WSwytZTNbb9kwYiv8ZQdSeZQoWPfxNhHgLAj5I028wPW8lUWUPzyzE4m9YlBqG9tlpZlkcdEcFbzE4dkQqu74HJYMH/QTE1NkkTtWiWoSkveB09B3xm0GAJ+vVmFjAMgGYJAF2WHzE0eFaQ9kfIWTJfTDJb8ZRgBgqzezUsFrSeSMEvXwpHXy8kmho3P2cR3QVRbUsIW9CGV9fvaU3nQBTx1WBMLok4u1ALoAUHICm5JZBHv/i8KcSNw1IK/ABEpW9HG/jOrnT8voJxtdQ==
  • Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=PshMOx5J781HywB16HUrabqRZXgWAS3Uyh7A21b/kXEZa8Ou4PAsx361ziUpvjzHYlnUY8fcikNrkdTZDZSwO/X4IYmYRbU0pHcU4+6CAmnmVYO8q05r1DNa2dAvokwdHwVi1tubo0RULGRbyRqmv3O3clzEQ05CeyUi2ls17tzmAHRFYytj2c9KvuiUYpGaKbKQN4XbYhNVBQqD25aycEMms97X9R2SCN4N4dhoxNx2dONv2AhZXpeeOu7xNV/vpILUiK2jKqIXtOOcyOeJ6vjUR86CTjDqPGeZl30xanWpXgwKdjbOV7E2YId0NVom3siMEOb1A4X8dpFw8ffjFQ==
  • Authentication-results-original: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=arm.com;
  • Cc: Bertrand Marquis <Bertrand.Marquis@xxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Julien Grall <julien@xxxxxxx>, Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxxx>
  • Delivery-date: Thu, 21 Apr 2022 16:55:09 +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: AQHYVXCysDCtUSKEqUams17wmJg+Jqz6WpOAgAA4twCAAALZAA==
  • Thread-topic: Need help to debug Arm SMMU issue seen on guests with passthrough devices

Hi Ayan,

> On 21 Apr 2022, at 5:44 pm, Ayan Kumar Halder <ayan.kumar.halder@xxxxxxxxxx> 
> wrote:
> 
> Hi Rahul,
> 
> On 21/04/2022 14:21, Rahul Singh wrote:
>> Hi Ayan,
>> 
>> > On 21 Apr 2022, at 12:12 pm, Ayan Kumar Halder 
>> > <ayan.kumar.halder@xxxxxxxxxx> wrote:
>> >
>> > Hi Arm/SMMU experts,
>> >
>> > Scenario :- I am trying to assign a device (eg mmc) to a guest which uses 
>> > smmu. I start the guest using "xl create -c ...". It works fine for the 
>> > first time. I am able to access the device.
>> >
>> > Now, when I destroy the guest and create again, I see this issue
>> 
>> Did you observe any other Xen error while deassigning and assigning the 
>> device ?
>> >
>> > (XEN) smmu: /axi/smmu@fd800000:  GFSR 0x00000002, GFSYNR0 0x00000000, 
>> > GFSYNR1 0x00000871, GFSYNR2 0x00000000
>> >
>> > 0x871 is the stream id used by mmc.
>> >
>> > We are using SMMU-500. So from the Arm SMMU v2 specs, it is "Unidentified 
>> > stream fault" for stream id "0x871".
>> 
>> Yes, you are right above error means that Unidentified stream fault. That 
>> means SMMU hardware is not set up for streamId 0x0000087
>> I just try to go through the SMMU code and observe that this issue may be 
>> related to iommu group but I am not maybe I am wrong.
>> I just created the patch that is not tested. Please try to apply the patch 
>> and test it once.
> 
> Many thanks for looking into this. With your patch, the issue is resolved.
> 
> Are you going to send out this patch for review ? You can add my "Tested-by" 
> tag.
> 

Good to know that the issue has been resolved. Yes, I will send the patch for 
review.

Regards,
Rahul


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.