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a=rsa-sha256; c=relaxed/relaxed; d=stancevic.com; s=dreamhost; t=1680917598; bh=la/yFC5BS6MKKninFxgeefnhJSls0usViO3A5BOrUtI=; h=Date:Subject:To:Cc:From:Content-Type:Content-Transfer-Encoding; b=Rque07UHK3S1AakuUgaGRupkgpRBGnEI7ftcjYrsnh3IRnl3wD4vv6UstZg5//36U or7trcQKTKJQZDKnWyAWrFcJynOKhTTqZE9XjNwmTBW7u4U3Jr0k9fHb3T4gBUTPC+ vxlIMlwohQrB9yuG+jgiBh8H6YJEtIkT+JeNHOgOWDEp3OJGkjioxbtttGfr8btcsz PEY9TwN8byecZpWnJ70RD6pgIpRjNNW1gIQ/XTxB4c6fdlAd5OfjGQz9oa6R9fw0cu 2EbSMFNn1Jc0h75RhMbxayqrNqopIYzAPRhbZbtAPPQ0DNZcnxHneQRoC9DDT2KFX1 WQgKU/GEwobzA== Message-ID: <879ef647-d766-28a0-a881-218bee965683@stancevic.com> Date: Fri, 7 Apr 2023 20:33:16 -0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Subject: =?UTF-8?Q?Re=3a_=5bLSF/MM/BPF_TOPIC=5d_BoF_VM_live_migration_over_C?= =?UTF-8?B?WEwgbWVtb3J54oCL?= Content-Language: en-US To: David Rientjes , James Houghton Cc: lsf-pc@lists.linux-foundation.org, nil-migration@lists.linux.dev, linux-cxl@vger.kernel.org, linux-mm@kvack.org References: <5d1156eb-02ae-a6cc-54bb-db3df3ca0597@stancevic.com> <8fada43c-8319-4d1a-9614-3ac3c76d59f3@google.com> From: Dragan Stancevic In-Reply-To: <8fada43c-8319-4d1a-9614-3ac3c76d59f3@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 7B29E100008 X-Stat-Signature: yxi9pg13arzck73b9fdti87jo1s1eow9 X-Rspam-User: X-HE-Tag: 1680917600-483596 X-HE-Meta: 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 C95w7aLG B/bzv1em4wKc7u47M7suHpCG+0K+EEpORHQ0cBBLiGB6kLMvB3FAiF9BJNtRyuQHuRr9Q+v8fLB5zUbWJWyDxXImMEK++UNl3OhpvNZBLfM0K4onPqS80/a5JOcFtlQKE6VJyKWnhQYwLYK6+7x0t8lA/0GNmpO/gD2dxUIgO/Dm0QAiU97I6OMsoXanl2YzpFMuAKB7B9ejbGtfpK4zHsSjwHPnWfbdhKHa4ogBJP/5PFk8o1BHQCULisEagmH1jmg5CZeeoDC0CKRqfEnOQVgMy2uAQXmqM5WUeJhmvo5a7msv7RJbxhbLNFRp2y4w3XKHO5bMAGHc32XT8U8W08SgWsuAnS5ut6bBQ51Ou/7wxHLMc4Vh11/+TkNz0lRhJXD+gJK3jRaEHNzPk10mvzyZstcAT4pYfBRIcVYfOld9hwKht1I8JxFkOVC/lDWWDr+uLjHmLkmlaHzpqqDlkUKfcND7NQ/lRwdQ3 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi David- On 4/7/23 18:17, David Rientjes wrote: > On Fri, 7 Apr 2023, James Houghton wrote: > >> On Fri, Apr 7, 2023 at 5:05 PM Dragan Stancevic wrote: >>> >>> Hi folks- >>> >>> if it's not too late for the schedule... >>> >>> I am starting to tackle VM live migration and hypervisor clustering over >>> switched CXL memory[1][2], intended for cloud virtualization types of loads. >>> >>> I'd be interested in doing a small BoF session with some slides and get >>> into a discussion/brainstorming with other people that deal with VM/LM >>> cloud loads. Among other things to discuss would be page migrations over >>> switched CXL memory, shared in-memory ABI to allow VM hand-off between >>> hypervisors, etc... >>> >>> A few of us discussed some of this under the ZONE_XMEM thread, but I >>> figured it might be better to start a separate thread. >>> >>> If there is interested, thank you. >> >> Hi Dragan, >> >> Thanks for bringing up this topic. I'd be very interested to be part >> of this BoF, as I'm also interested in using CXL.mem as a live >> migration mechanism. >> > > Thanks for cc'ing me, this would be very interesting to talk about. Count > me in! > >>> [1]. High-level overview available at http://nil-migration.org/ >>> [2]. Based on CXL spec 3.0 >>> > > Dragan: I'm curious about the reference to CXL spec 3.0 here, is there > something specific about 3.0 that this work depends on or should we be > good-to-go with 2.0 as well? (Are you referring to 3.0 for security > extensions?) I'm referencing 3.0 with regards to switched/shared memory as defined in Compute Express Link Specification r3.0, v1.0 8/1/22, Page 51, figure 1-4, black color scheme circle(3) and bars. It may be possible to do it with 2.0 but as far as I understand[1] the 2.0 spec it might be a lot more involved/clunky. I think new 3.0 features make it easier [1]. I would love to read 2.0 spec, but I don't have access to 2.0 spec(only 3.0). But that is my understanding from speaking with some CXL folks at last years plumbers when I floated this idea with them. -- Peace can only come as a natural consequence of universal enlightenment -Dr. Nikola Tesla