[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH 3/4] xen/arm, libxl: Revert XEN_DOMCTL_shadow_op; use p2m mempool hypercalls
- To: Stefano Stabellini <sstabellini@xxxxxxxxxx>
- From: Andrew Cooper <Andrew.Cooper3@xxxxxxxxxx>
- Date: Wed, 16 Nov 2022 01:48:17 +0000
- Accept-language: en-GB, en-US
- Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=citrix.com; dmarc=pass action=none header.from=citrix.com; dkim=pass header.d=citrix.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=z5mgmGSt1k6ofONfwu+a//Yc5uKeib2zz9aLXoaAEkA=; b=lmweX52P5NegXgdsLXBKMGs2VHt3jToh9HKsCqducfMS0yhOZcWuTPYFzXIUFHCmXH+Ytn6iqIJYhbIFuMJfJzGtTJgHRk03PTq0vQhCuylgHi4atr2wD4SWsT7Qi1cuCLTsVUfgWe714VZs1ka31BIvq0dOdkeSikehm7j23KyUIgE3Q2SXmSt7jVcI1tQOONu9hzlhH605UG/eIG/hYNK0MHupJ0210V5QnDzWnd4hnzLizOdHYNGhFncOgfJHQyq/u4BpER6nEU3SuruI6IqxNDrK9EmfxbSZZ+8qal7MKcvP7P5MzLCAUMKfrug1sz1Riu8QIUdWVG1yuDv8dA==
- Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=U/yE3yFyF3OhC988IJ6lLfl5uTEbPTV74+EBzdNaPoVRjMO5+LjOD08pV5k7y6FD9U2fvIxlLnU5gv8c5i31vpEETyeB+ZIs569MXy9LcjUTm84Ig7bWhiAguOyxnfGz5zDQY10X/Ihvoc/YIPLrSh5Lz1pbs6VYnYHSLe7ZiWf78ejaRAV0cvxazbUwYMmsgfcm4B5nluFaHLp0MLEYuC35wCla0HjdAYntn8oyPoCPijSmHhR6hlNqtbjG+DYQFAiwflHbWjmNU+Ouuurjblje+bIim1c/SrFfzvkZbEEKoik7VRIanlFB38ePcwnZ72W+9dI8H/539AK8n3VN1A==
- Authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=citrix.com;
- Cc: Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>, Xen Security Team <security@xxxxxxx>, Jan Beulich <JBeulich@xxxxxxxx>, Roger Pau Monne <roger.pau@xxxxxxxxxx>, Wei Liu <wl@xxxxxxx>, Julien Grall <julien@xxxxxxx>, Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>, Bertrand Marquis <bertrand.marquis@xxxxxxx>, Henry Wang <Henry.Wang@xxxxxxx>, Anthony Perard <anthony.perard@xxxxxxxxxx>
- Delivery-date: Wed, 16 Nov 2022 01:48:40 +0000
- Ironport-data: A9a23:2dCvaa9YSw5IqW8BDt3qDrUDLn+TJUtcMsCJ2f8bNWPcYEJGY0x3z GccWzyCM/mIMWfwct1/OY23o0kFvsDcxoIwSFNrrSg8E34SpcT7XtnIdU2Y0wF+jCHgZBk+s 5hBMImowOQcFCK0SsKFa+C5xZVE/fjUAOG6UKucYHsZqTZMEE8JkQhkl/MynrlmiN24BxLlk d7pqojUNUTNNwRcawr40Ire7kIx1BjOkGlA5AZnPKkW5AS2e0Q9V/rzG4ngdxMUfaEMdgKKb 76r5K20+Grf4yAsBruN+losWhRXKlJ6FVHmZkt+A8BOsDAbzsAB+v9T2M4nQVVWk120c+VZk 72hg3ASpTABZcUgkMxFO/VR/roX0aduoNcrKlDn2SCfItGvn9IBDJyCAWlvVbD09NqbDklR5 fU1Lj40RyuNqKHp5a2+Fdhni80seZyD0IM34hmMzBn/JNN/G9XpZfWP4tVVmjAtmspJAPDSI dIDbiZiZwjBZBsJPUoLDJU5n6GjgXyXnz9w8QrJ4/ZopTWOilUujdABM/KMEjCObexTklyVu STt+GPhDwtBHNee1SCE4jSngeqncSbTCN5OReTkraACbFu79148DhJHTXCA/9KzrRWyQOAYd 0wG9X97xUQ13AnxJjXnZDWju2KNtBMYX9tWEsU55RuLx66S5ByWbkAUQzgEZNE4ucseQT0xy kTPj97vHSZosrCeVTSa7Lj8hSi/MjUPLHMTTT8JS00C+daLiKMZgw/LT91jOLWoldCzEjb1q xiVqAAuirNVitQEv4254FTGjjSEtpXPCAkv6W3/YGWh6Q9oYZ+/UKah41Pb8PVoIZ6QSx+Ku 31ss8KT9vwUBJeB0imEWvwQHaqB7uyAdjbbhDZHP5Qn7SXrxHelcqhZ+jQ4L0BsWvvoYhfsa U7X/AlXtJlaOSLwabctOt3sTcM30aLnCNLpEOjOacZDaYRwcwnB+zxyYUmX3Cbml01EfbwDB Kp3uP2EVR4yYZmLBhLsLwvB+dfHHhwD+F4=
- Ironport-hdrordr: A9a23:50n9YqudRdGCr5MuW++Cq8xL7skCXoAji2hC6mlwRA09TyXGra 2TdaUgvyMc1gx7ZJh5o6H6BEGBKUmslqKceeEqTPqftXrdyRGVxeZZnMffKlzbamfDH4tmuZ uIHJIOb+EYYWIasS++2njBLz9C+qjJzEnLv5a5854Fd2gDBM9dBkVCe3+m+yZNNWt77O8CZf 6hD7181l+dkBosDviTNz0gZazuttfLnJXpbVovAAMm0hCHiXeF+aP3CB+R2zYZSndqza05+W bIvgTl7uH72svLiyP05iv21dB7idHhwtxMCIiljdUUECzljkKFdZlsQLqLuREyuaWK5EwxmN fBjh88N4BY6m/XfEuyvRzxsjOQngoG2jvH8xu1kHHjqcv2SHYREMxan79UdRPf9g4JoMx8+L gj5RPbi7NnSTf72Ajt7dnBUB9n0mCup2A5rOIVh3tDFaMDdb5qq5AF9k89KuZDIMu60vFjLA BdNrCa2B9kSyLdU5kfhBg3/DWYZAV2Iv5BeDlbhiXa6UkMoJkz9Tpk+CVWpAZ9yHt6cegF2w 2MCNUXqFkFJPVmEp5VFaMPR9C6BXfKRg+JOGWOIU7/HKVCIH7VrYXriY9Frd1CVaZ4u6faoq 6xJm9wpCo3YQbjGMeO1JpE/lTER3i8Ry3kzoVb64JisrPxSbL3OWnbIWpe2PeIsrEaGInWSv yzMJVZD7vqKnbvA59A20n7V4NJIXcTXcUJspIwWk6IoMjMNor239arOMr7Nf7oC3IpS2n/Cn wMUHz6I9hB9FmiXjvijB3YSxrWCzjCFFJLYd3nFsQoufsw39d3w3koYHyCl7G2ACwHtLAqd0 1jJ76imr+npACNjBT101k=
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
- Thread-index: AQHY6SSlXP4isouqyE+BbtcNRl5Xnq5A5cGAgAAC9IA=
- Thread-topic: [PATCH 3/4] xen/arm, libxl: Revert XEN_DOMCTL_shadow_op; use p2m mempool hypercalls
On 16/11/2022 01:37, Stefano Stabellini wrote:
> On Wed, 26 Oct 2022, Andrew Cooper wrote:
>> This reverts most of commit cf2a68d2ffbc3ce95e01449d46180bddb10d24a0, and
>> bits
>> of cbea5a1149ca7fd4b7cdbfa3ec2e4f109b601ff7.
>>
>> First of all, with ARM borrowing x86's implementation, the logic to set the
>> pool size should have been common, not duplicated. Introduce
>> libxl__domain_set_p2m_pool_size() as a shared implementation, and use it from
>> the ARM and x86 paths. It is left as an exercise to the reader to judge how
>> libxl/xl can reasonably function without the ability to query the pool
>> size...
>>
>> Remove ARM's p2m_domctl() infrastructure now the functioanlity has been
>> replaced with a working and unit tested interface.
>>
>> This is part of XSA-409 / CVE-2022-33747.
> Genuine question: I can see this patch removes the implementation of
> XEN_DOMCTL_SHADOW_OP_SET_ALLOCATION on ARM. It also switches libxl (both
> ARM and x86) to the new hypercall.
>
> Why keep the old hypercall (XEN_DOMCTL_shadow_op and
> XEN_DOMCTL_SHADOW_OP_SET_ALLOCATION) implementation on x86 (not on ARM)?
>
> Is that because it was only recently implemented? And not actually
> present in any past Xen release?
>
> If so, please add a note about this in the commit message. Also, if that
> is the case, I think this patch series should go in 4.17. If it is too
> late to get it in before the release, then we should backport it to 4.17
> as soon as possible. That's because ideally we want to keep the
> hypercall interface changes down to a minimum.
On ARM, the hypercall has existed for a little over 4 weeks, and isn't
in any released version of Xen (yet).
On x86, the hypercall has existed for more than a decade, and has known
out-of-tree users. It needs to be deprecated properly, which in this
case means "phased out in the 4.18 cycle once known callers have been
adapted to the new hypercall".
~Andrew
|
