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

RE: [PATCH v7 2/5] xen/arm64: Rework the memory layout


  • To: Julien Grall <julien@xxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxxx>
  • From: Henry Wang <Henry.Wang@xxxxxxx>
  • Date: Mon, 17 Apr 2023 04:58:51 +0000
  • Accept-language: zh-CN, 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=BPH0HizTlrsxooKXXMwgC2ytuuQzv08uUCOKt2VaMqY=; b=NbPmL/PJgiG0icgEMyk4i2X1qJqP1saWg+inbRbKx8W2JJD7mXY9IY6XBT1gpYElR/kuJ+46NyFWU5eE59I9xo95StkBeOQeyOg/iDS1noqJmKJXZyLlJUuFu9CudLvCzqLQu9avK43NcW0LrN/nJH6zmSHvSKzF4cn5RUVLHp1UQPSA4aN5ER0DYYL1k76+FZmBuotDh6VmKUeK54zIUZm2cRCZ3InVwig/VOt1ivNdcp5exzL4tSmxIZbvWAv5NwXYM1aBYnYemUUzG2ySzKg2yOLlKlhC6I8CxOI2wbcV5LGscL3yYKX43bNOA4gVmMFeQOkuUFJl0clCPggJ9g==
  • Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=ACW2nwKqRoCy5byk2BP5IukdO0mfETcpniYmThIQ1wOCUC2fbkUp2OMMUjJ6OInpyqNgAKs48tnlCkVJQ0AOQSxenk553MvqNF7mq59v/EhLEd1/mieaR9NrmyUReJpJVDcPLkkfCVBxcdekwHNvismVaiLveaz+onIeShLYN6Mfvo6S6uDuf2FfoT9iPsJBEXMyw8bGBZkJ/bVSnlcPNixqoefemFNmNODV6ofdnD0v2Na+EMUwKdS57Q0oOqax6NtRGZKwR2/pBP8IePDbWw1atUQvXMtP+Y3iV3Eb+hR/9Eva/MDPHAmk/1RJ2qT7uUU6B9Pm/KqaHJSO20Nkwg==
  • Authentication-results-original: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=arm.com;
  • Cc: Luca Fancellu <Luca.Fancellu@xxxxxxx>, "michal.orzel@xxxxxxx" <michal.orzel@xxxxxxx>, Julien Grall <jgrall@xxxxxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Bertrand Marquis <Bertrand.Marquis@xxxxxxx>, Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>
  • Delivery-date: Mon, 17 Apr 2023 04:59:42 +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: AQHZcHBVTtqn5UnQqEuWlkR+HSSWja8uwBIw
  • Thread-topic: [PATCH v7 2/5] xen/arm64: Rework the memory layout

Hi Julien,

> -----Original Message-----
> Subject: [PATCH v7 2/5] xen/arm64: Rework the memory layout
> 
> From: Julien Grall <jgrall@xxxxxxxxxx>
> 
> Xen is currently not fully compliant with the Arm Arm because it will
> switch the TTBR with the MMU on.
> 
> In order to be compliant, we need to disable the MMU before
> switching the TTBR. The implication is the page-tables should
> contain an identity mapping of the code switching the TTBR.
> 
> In most of the case we expect Xen to be loaded in low memory. I am aware
> of one platform (i.e AMD Seattle) where the memory start above 512GB.
> To give us some slack, consider that Xen may be loaded in the first 2TB
> of the physical address space.
> 
> The memory layout is reshuffled to keep the first four slots of the zeroeth
> level free. All the regions currently in L0 slot 0 will not be part of
> slot 4 (2TB). This requires a slight tweak of the boot code because
> XEN_VIRT_START (2TB + 2MB) cannot be used as an immediate.
> 
> This reshuffle will make trivial to create a 1:1 mapping when Xen is
> loaded below 2TB.
> 
> Lastly, take the opportunity to check a compile time if any of the
> regions may overlap with the reserved area for identity mapping.
> 
> Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>

This time I used our CI to test this series patch by patch on top of staging
today (Apr 17), so that we can see if the qemu issue reported by Bertrand
in v6 still persists.

I can confirm all boards including the qemu-arm64 passed this time, so:

Tested-by: Henry Wang <Henry.Wang@xxxxxxx>

Kind regards,
Henry



 


Rackspace

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