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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EF3D0D10F20 for ; Wed, 26 Nov 2025 10:21:37 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 35F796B0031; Wed, 26 Nov 2025 05:21:37 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 30FDA6B0032; Wed, 26 Nov 2025 05:21:37 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1FF7C6B0062; Wed, 26 Nov 2025 05:21:37 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 0D8DF6B0031 for ; Wed, 26 Nov 2025 05:21:37 -0500 (EST) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 6F9504FFD0 for ; Wed, 26 Nov 2025 10:21:36 +0000 (UTC) X-FDA: 84152366592.22.1037A0F Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf07.hostedemail.com (Postfix) with ESMTP id B23564000D for ; Wed, 26 Nov 2025 10:21:34 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=axZ+8RER; spf=pass (imf07.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1764152494; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=e93oI2y5ZGWKoBIg0MsaHwMs0o9inlz2F6nG6Nm4DII=; b=EiqP5xh88II67K3VeXRgTOedSuJ7CAt4m2vst6oGT05pteQc4serCauPU9HVCaoIy0EdOI B3GDmCSCBWDePLC5lTm2Zc+wEYl2xkIIbSEkGC3haQ1JrsXJUiRMk/AnFjqXSyEyHyzTWW kREYELsE1fuIfY7DquRciZe2niM7glA= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1764152494; a=rsa-sha256; cv=none; b=r3biBMtEY1xAaYPUydAQPoqJTZxXlgbLW9NehUXbWU5qjPIONaxOPlf3ARpVRc4/QDTH5o rg4iUjZ87tnQnn71rUz/lm8yUuWhkVbdbI2m67uQH9eK9mdHvuZOhhkPpfKIMbGRMzx6sv 9cRmqNWPpPIAGQ6ij4q/iYYv7yr/WoM= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=axZ+8RER; spf=pass (imf07.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id D150D43248; Wed, 26 Nov 2025 10:21:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C3C92C113D0; Wed, 26 Nov 2025 10:21:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764152493; bh=BcAJVj6qcG98+h3lf093r2ZIpIwJSDn8eL4opofTeJU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=axZ+8RERz4f1+HlUZSmBzSNN+DZ5wmCTdjZPn+Sn67DidzcPbG/trkh2LUzqBiNtF 0sFGfznqxNBm7RWh6g+IVpJmKoHoafpH8Yt7dbwq7doRbnBSKsf7N4K7+bBhL7qlOI 5aprOxQI8T39czEKCl0l1bC44w/FvReoiJi63qEA8zrUs1iSVcJIq01THJwLkwOHUj qsTRe6tkhu39lUVNgjh1wtKAn0la7WVupbaLryeHQVLDH7dLm8ptKOkmnv2h7q2zFf 19T/KELXMc/RHK6snLqr+wIIhe+an8YnI+2fVfJUVgS+S9sxhF5DCjtHL7SLpE/S2K CjxAmheibuLzw== Message-ID: Date: Wed, 26 Nov 2025 11:21:26 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 2/5] userfaultfd, shmem: use a VMA callback to handle UFFDIO_CONTINUE To: Mike Rapoport , linux-mm@kvack.org Cc: Andrea Arcangeli , Andrew Morton , Axel Rasmussen , Baolin Wang , Hugh Dickins , James Houghton , "Liam R. Howlett" , Lorenzo Stoakes , Michal Hocko , Nikita Kalyazin , Paolo Bonzini , Peter Xu , Sean Christopherson , Shuah Khan , Suren Baghdasaryan , Vlastimil Babka , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org References: <20251125183840.2368510-1-rppt@kernel.org> <20251125183840.2368510-3-rppt@kernel.org> From: "David Hildenbrand (Red Hat)" Content-Language: en-US In-Reply-To: <20251125183840.2368510-3-rppt@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam12 X-Rspam-User: X-Rspamd-Queue-Id: B23564000D X-Stat-Signature: op1t1t4og7ka8tny9y17z3y14d4ktzey X-HE-Tag: 1764152494-352651 X-HE-Meta: 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 J8F24r5L /dzxh/phtJxDkSGKs8fcAmPgYUO5xX6yBkTtsE7DdcSSALSTa54SvaTLMRZPIJQH07q3QD7GQ5jy5W8d/rMYLyiZTMETJRa2CEkNhA1vh09k0snuLdx6fZZdhXtF8wX5NHqoBVJt3Wpd5dmAC3WLHRB9iDBdvjFateRF13mPKBG3QibjZmBL1L8AQx6E3+wZ5whCCZ4fnMgrELOxjq2WteMuEYnFDW6sa/NNGkABzab/AXb1pHIBVSn9m/ULighIDzwHMJTkeu3TQuT/OzxFhnS5Q7DN5bae7+MpB X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 11/25/25 19:38, Mike Rapoport wrote: > From: "Mike Rapoport (Microsoft)" > > When userspace resolves a page fault in a shmem VMA with UFFDIO_CONTINUE > it needs to get a folio that already exists in the pagecache backing > that VMA. > > Instead of using shmem_get_folio() for that, add a get_folio() method to > 'struct vm_operations_struct' that will return a folio if it exists in > the VMA's pagecache at given pgoff. > > Implement get_folio() method for shmem and slightly refactor > userfaultfd's mfill_atomic() and mfill_atomic_pte_continue() to support > this new API. > > Signed-off-by: Mike Rapoport (Microsoft) > --- Acked-by: David Hildenbrand (Red Hat) -- Cheers David