From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 99278C282EC for ; Fri, 7 Mar 2025 01:29:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: Message-ID:Date:References:In-Reply-To:Subject:Cc:To:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=j2br9eadG+prJRkVEuLtzkTzi1DZEsFzj7t8tTGOrhQ=; b=hWSMksS+gKEXsJH0WPdSDkvFXe qW1fv9EwsEikFUMYhwkt5f986Q178bsJvYO1cgSbjPxWoP+S8TCdYXbFeiLQO1U/KLu0OIejFwSrz t0SHpopTkfeFlM4g0oir+E03Gye7534G1NUswWNycuZkXB/X8ekoJGa2XmKhGiFkSXSG6uiZANXVY hHWBN1o1ZtWVPOUIxYjylrlwadN06Aijf5s+uXeVX+VQ92x0jdjeXJeIyYv7SUafm98wT+fZjtWcP T2dTiNQqVupcvvkhd2NJ3cUhg74Xrlxj7z90yOWCNdKXWRXv801nIuOsJJq1t6lPwzMjblWe+IwY6 lfsUF9/Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tqMWR-0000000CnjO-195S; Fri, 07 Mar 2025 01:29:07 +0000 Received: from nyc.source.kernel.org ([2604:1380:45d1:ec00::3]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tqMDn-0000000Ckit-291r for kexec@lists.infradead.org; Fri, 07 Mar 2025 01:09:52 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id 6BC1CA44A7C; Fri, 7 Mar 2025 01:04:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2CECDC4CEE0; Fri, 7 Mar 2025 01:09:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741309789; bh=yKuo8ItUdzoMnE+DZFQ9ipnfPDk0P9XbGS1ILoFZ5kk=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=YyRSh1AY/kLvcXE2EMoEKJ23nXytxgWZvz58cGiz5RT3NrBZHUXzJn24OjryqiwRV laegr90sLsUyToXcAMLFgdV13xazA5Ncou0kjL3VIDucIF2qqlGwPO6QsYUKE8GLas YaI8zgX/SIKLti5MMpwGGmiylScsZ/4GQYOFIj415F/v77L9Gxj5i/lxcEmpk76X7D 7TtvZ8Cunn4C9kkzpwIVBV/h5d9UEyqDz3Z303MIBDZG+1ndgTNRQfHUfeIHfoeu5p v9uj0lkcpzBVG2ZHgnWcdaGyr2/iF56Rp84Ikzxkm3wOIy0JB/kuoa8VtdfGoQ/0zc c/9iimlBG4GIA== From: Pratyush Yadav To: David Rientjes Cc: Alexander Graf , Anthony Yznaga , Dave Hansen , David Hildenbrand , Frank van der Linden , James Gowans , Jason Gunthorpe , Junaid Shahid , Matthew Wilcox , Mike Rapoport , Pankaj Gupta , Pasha Tatashin , Pratyush Yadav , Vipin Sharma , Vishal Annapurve , "Woodhouse, David" , linux-mm@kvack.org, kexec@lists.infradead.org Subject: Re: [Hypervisor Live Update] Notes from February 24, 2025 In-Reply-To: <7154b857-01cf-a8c6-ea02-51d095bafabf@google.com> References: <7154b857-01cf-a8c6-ea02-51d095bafabf@google.com> Date: Fri, 07 Mar 2025 01:09:45 +0000 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250306_170951_633916_E141ADA3 X-CRM114-Status: GOOD ( 22.34 ) X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org Hi all, On Sun, Mar 02 2025, David Rientjes wrote: > Hi everybody, > > Here are the notes from the last Hypervisor Live Update call that happened > on Monday, February 24. Thanks for everybody who was involved! > [...] > > Pratyush took the AI to look at implementation on memfd. Mike took the > AI to look at memory reservation. > > ----->o----- > I pivoted the discussion toward fdbox which ended up never being posted > upstream. Pratyush provided the link to the most recent code: > https://github.com/agraf/linux-2.6/blob/kvm-kho-gmem-test/drivers/misc/fdbox.c > This work likely would need to be picked up to pursue upstream because > the current code has several TODO's. (A struct miscdevice was called out > as curious.) > > It was noted that it would be difficult to support memfd without > something like fdbox, so whether the fdbox code itself were upstreamed or > it becomes more generic from the work on memfd, the base support would > need to be provided somehow. > > Mike and Jason suggested designing fdbox and then starting to use it for > memfd. This would need to be aligned by stakeholders, including the UAPI > for fdbox. Pratyush will be looking into fdbox or inventing something > similar while working on memfd. > > We need to propose the fdbox design and UAPI. As promised, I have taken the last couple weeks in coming up with a basic FDBox design, along with having memfd use it (currently via shmem, since I am more familiar with that than with hugetlbfs). The patches can be found at [0]. I am travelling next week so I am not sure if I will be able to attend the next session. If I do, I would like to talk more about the patches and FDBox if time permits. Anyway, looking forward to getting some feedback on the patches :-) [0] https://lore.kernel.org/linux-mm/20250307005830.65293-1-ptyadav@amazon.de/T/#u [...] -- Regards, Pratyush Yadav