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]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7CB13C021B2 for ; Thu, 20 Feb 2025 11:28:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id EAD6A2802CA; Thu, 20 Feb 2025 06:28:47 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E5E862802C6; Thu, 20 Feb 2025 06:28:47 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CFE862802CA; Thu, 20 Feb 2025 06:28:47 -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 B11782802C6 for ; Thu, 20 Feb 2025 06:28:47 -0500 (EST) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 5C1A94BA0A for ; Thu, 20 Feb 2025 11:28:47 +0000 (UTC) X-FDA: 83140100694.07.C57CFF6 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) by imf24.hostedemail.com (Postfix) with ESMTP id 00B71180009 for ; Thu, 20 Feb 2025 11:28:44 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=FKaCqLpu; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=rlFD5gzh; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=APqZHmmf; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=CiwI10S6; spf=pass (imf24.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.130 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1740050925; 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=piqxfvLXdbGusjFDiJqlKR9OqlTBD0wfyNhdz+Y8Rdo=; b=NdSWXSWzSHA4sfDwRHKXpZS+KrwidFJYq8mfAJPbFY6UggBNgWvkfUdB1F91BV/4k4auWQ 9OTO8uDk1ijp3hS92hqOq71z4qJkEmvXgOUQbcsosuZ+wBAx8K4FM0sDsfTgg8lzDH2VqD JJgK6OK8oLR7ajoErMjO/mloVqE/8JA= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1740050925; a=rsa-sha256; cv=none; b=kbO+Km953Wl9EDaH2S9hi06FH0r+kHvfW/JBdpqk/kdB+Rn9Ik8FiO3fhfC9bYgt4usHvP uy8AJTO0T4AUSgqT4V2riXcRUVSRyObuhQf0Bzyzf3D3dNzl2NpCsuROrtUXuG1QAWjXJo rkfNyaEj5cf9CRWwo2D5rWnlrEe6Cao= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=FKaCqLpu; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=rlFD5gzh; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=APqZHmmf; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=CiwI10S6; spf=pass (imf24.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.130 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id D58932117D; Thu, 20 Feb 2025 11:28:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1740050923; h=from:from:reply-to: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:autocrypt:autocrypt; bh=piqxfvLXdbGusjFDiJqlKR9OqlTBD0wfyNhdz+Y8Rdo=; b=FKaCqLpupK+EyUHi0f5GBjf/hHx6IevA2tQAnj9epH03L4XgghXSqARmt2pRcN6MdFUepq eHoZ7/GqmGDWWcEgeXSjTON2/vZ4yBYdmcR58pRV/61cc3Pyn/TAHu8q6VxTrqlD3ck/53 6FieLDeWaRrFFlqO7zMGUONAIFKW254= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1740050923; h=from:from:reply-to: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:autocrypt:autocrypt; bh=piqxfvLXdbGusjFDiJqlKR9OqlTBD0wfyNhdz+Y8Rdo=; b=rlFD5gzhMdEsIryvM5UjJumhGYqjRqi/q+pBy7fszYOU0vXWNJKu6Xo3ICiqyrFKD7IEX5 JBBQMXJTJPBdQVDA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1740050922; h=from:from:reply-to: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:autocrypt:autocrypt; bh=piqxfvLXdbGusjFDiJqlKR9OqlTBD0wfyNhdz+Y8Rdo=; b=APqZHmmf3yd7nneZMwYZZPy8tKLoW6KyOuei3flSDhzzrcaFGr8Zk/dVEwiLuXBCQwX+Yi 7L5j3necD2oexkK6n7KK8UqJ/JLPI5iRMdwCo1OG0+5LDoq4jSFRTCqxFqnqdhW5cadvt9 eFm3b1SoH70/NubZvEi51XF/Q758vr8= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1740050922; h=from:from:reply-to: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:autocrypt:autocrypt; bh=piqxfvLXdbGusjFDiJqlKR9OqlTBD0wfyNhdz+Y8Rdo=; b=CiwI10S6vS7UlpiQa6s/xEdu6SWaatdK6ULi6/FNojnSrLByr9xGKnQvsiW0PlQI9//8N0 gn6DpRvV1wLDvQCQ== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id CB16D13A42; Thu, 20 Feb 2025 11:28:41 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id TXtIK+kRt2d4HQAAD6G6ig (envelope-from ); Thu, 20 Feb 2025 11:28:41 +0000 Message-ID: <5746ef9f-92da-4f83-bdf8-96169b090cff@suse.cz> Date: Thu, 20 Feb 2025 12:28:39 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 02/11] KVM: guest_memfd: Handle final folio_put() of guest_memfd pages Content-Language: en-US To: David Hildenbrand , Fuad Tabba , kvm@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-mm@kvack.org Cc: pbonzini@redhat.com, chenhuacai@kernel.org, mpe@ellerman.id.au, anup@brainfault.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, seanjc@google.com, viro@zeniv.linux.org.uk, brauner@kernel.org, willy@infradead.org, akpm@linux-foundation.org, xiaoyao.li@intel.com, yilun.xu@intel.com, chao.p.peng@linux.intel.com, jarkko@kernel.org, amoorthy@google.com, dmatlack@google.com, yu.c.zhang@linux.intel.com, isaku.yamahata@intel.com, mic@digikod.net, vannapurve@google.com, ackerleytng@google.com, mail@maciej.szmigiero.name, michael.roth@amd.com, wei.w.wang@intel.com, liam.merwick@oracle.com, isaku.yamahata@gmail.com, kirill.shutemov@linux.intel.com, suzuki.poulose@arm.com, steven.price@arm.com, quic_eberman@quicinc.com, quic_mnalajal@quicinc.com, quic_tsoni@quicinc.com, quic_svaddagi@quicinc.com, quic_cvanscha@quicinc.com, quic_pderrin@quicinc.com, quic_pheragu@quicinc.com, catalin.marinas@arm.com, james.morse@arm.com, yuzenghui@huawei.com, oliver.upton@linux.dev, maz@kernel.org, will@kernel.org, qperret@google.com, keirf@google.com, roypat@amazon.co.uk, shuah@kernel.org, hch@infradead.org, jgg@nvidia.com, rientjes@google.com, jhubbard@nvidia.com, fvdl@google.com, hughd@google.com, jthoughton@google.com References: <20250211121128.703390-1-tabba@google.com> <20250211121128.703390-3-tabba@google.com> <8ddab670-8416-47f2-a5a6-94fb3444f328@redhat.com> From: Vlastimil Babka Autocrypt: addr=vbabka@suse.cz; keydata= xsFNBFZdmxYBEADsw/SiUSjB0dM+vSh95UkgcHjzEVBlby/Fg+g42O7LAEkCYXi/vvq31JTB KxRWDHX0R2tgpFDXHnzZcQywawu8eSq0LxzxFNYMvtB7sV1pxYwej2qx9B75qW2plBs+7+YB 87tMFA+u+L4Z5xAzIimfLD5EKC56kJ1CsXlM8S/LHcmdD9Ctkn3trYDNnat0eoAcfPIP2OZ+ 9oe9IF/R28zmh0ifLXyJQQz5ofdj4bPf8ecEW0rhcqHfTD8k4yK0xxt3xW+6Exqp9n9bydiy tcSAw/TahjW6yrA+6JhSBv1v2tIm+itQc073zjSX8OFL51qQVzRFr7H2UQG33lw2QrvHRXqD Ot7ViKam7v0Ho9wEWiQOOZlHItOOXFphWb2yq3nzrKe45oWoSgkxKb97MVsQ+q2SYjJRBBH4 8qKhphADYxkIP6yut/eaj9ImvRUZZRi0DTc8xfnvHGTjKbJzC2xpFcY0DQbZzuwsIZ8OPJCc LM4S7mT25NE5kUTG/TKQCk922vRdGVMoLA7dIQrgXnRXtyT61sg8PG4wcfOnuWf8577aXP1x 6mzw3/jh3F+oSBHb/GcLC7mvWreJifUL2gEdssGfXhGWBo6zLS3qhgtwjay0Jl+kza1lo+Cv BB2T79D4WGdDuVa4eOrQ02TxqGN7G0Biz5ZLRSFzQSQwLn8fbwARAQABzSBWbGFzdGltaWwg QmFia2EgPHZiYWJrYUBzdXNlLmN6PsLBlAQTAQoAPgIbAwULCQgHAwUVCgkICwUWAgMBAAIe AQIXgBYhBKlA1DSZLC6OmRA9UCJPp+fMgqZkBQJkBREIBQkRadznAAoJECJPp+fMgqZkNxIQ ALZRqwdUGzqL2aeSavbum/VF/+td+nZfuH0xeWiO2w8mG0+nPd5j9ujYeHcUP1edE7uQrjOC Gs9sm8+W1xYnbClMJTsXiAV88D2btFUdU1mCXURAL9wWZ8Jsmz5ZH2V6AUszvNezsS/VIT87 AmTtj31TLDGwdxaZTSYLwAOOOtyqafOEq+gJB30RxTRE3h3G1zpO7OM9K6ysLdAlwAGYWgJJ V4JqGsQ/lyEtxxFpUCjb5Pztp7cQxhlkil0oBYHkudiG8j1U3DG8iC6rnB4yJaLphKx57NuQ PIY0Bccg+r9gIQ4XeSK2PQhdXdy3UWBr913ZQ9AI2usid3s5vabo4iBvpJNFLgUmxFnr73SJ KsRh/2OBsg1XXF/wRQGBO9vRuJUAbnaIVcmGOUogdBVS9Sun/Sy4GNA++KtFZK95U7J417/J Hub2xV6Ehc7UGW6fIvIQmzJ3zaTEfuriU1P8ayfddrAgZb25JnOW7L1zdYL8rXiezOyYZ8Fm ZyXjzWdO0RpxcUEp6GsJr11Bc4F3aae9OZtwtLL/jxc7y6pUugB00PodgnQ6CMcfR/HjXlae h2VS3zl9+tQWHu6s1R58t5BuMS2FNA58wU/IazImc/ZQA+slDBfhRDGYlExjg19UXWe/gMcl De3P1kxYPgZdGE2eZpRLIbt+rYnqQKy8UxlszsBNBFsZNTUBCACfQfpSsWJZyi+SHoRdVyX5 J6rI7okc4+b571a7RXD5UhS9dlVRVVAtrU9ANSLqPTQKGVxHrqD39XSw8hxK61pw8p90pg4G /N3iuWEvyt+t0SxDDkClnGsDyRhlUyEWYFEoBrrCizbmahOUwqkJbNMfzj5Y7n7OIJOxNRkB IBOjPdF26dMP69BwePQao1M8Acrrex9sAHYjQGyVmReRjVEtv9iG4DoTsnIR3amKVk6si4Ea X/mrapJqSCcBUVYUFH8M7bsm4CSxier5ofy8jTEa/CfvkqpKThTMCQPNZKY7hke5qEq1CBk2 wxhX48ZrJEFf1v3NuV3OimgsF2odzieNABEBAAHCwXwEGAEKACYCGwwWIQSpQNQ0mSwujpkQ PVAiT6fnzIKmZAUCZAUSmwUJDK5EZgAKCRAiT6fnzIKmZOJGEACOKABgo9wJXsbWhGWYO7mD 8R8mUyJHqbvaz+yTLnvRwfe/VwafFfDMx5GYVYzMY9TWpA8psFTKTUIIQmx2scYsRBUwm5VI EurRWKqENcDRjyo+ol59j0FViYysjQQeobXBDDE31t5SBg++veI6tXfpco/UiKEsDswL1WAr tEAZaruo7254TyH+gydURl2wJuzo/aZ7Y7PpqaODbYv727Dvm5eX64HCyyAH0s6sOCyGF5/p eIhrOn24oBf67KtdAN3H9JoFNUVTYJc1VJU3R1JtVdgwEdr+NEciEfYl0O19VpLE/PZxP4wX PWnhf5WjdoNI1Xec+RcJ5p/pSel0jnvBX8L2cmniYnmI883NhtGZsEWj++wyKiS4NranDFlA HdDM3b4lUth1pTtABKQ1YuTvehj7EfoWD3bv9kuGZGPrAeFNiHPdOT7DaXKeHpW9homgtBxj 8aX/UkSvEGJKUEbFL9cVa5tzyialGkSiZJNkWgeHe+jEcfRT6pJZOJidSCdzvJpbdJmm+eED w9XOLH1IIWh7RURU7G1iOfEfmImFeC3cbbS73LQEFGe1urxvIH5K/7vX+FkNcr9ujwWuPE9b 1C2o4i/yZPLXIVy387EjA6GZMqvQUFuSTs/GeBcv0NjIQi8867H3uLjz+mQy63fAitsDwLmR EP+ylKVEKb0Q2A== In-Reply-To: <8ddab670-8416-47f2-a5a6-94fb3444f328@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Action: no action X-Rspam-User: X-Rspamd-Queue-Id: 00B71180009 X-Rspamd-Server: rspam07 X-Stat-Signature: n6ei79bsxxarzzm6hh73mj4g8utjru4s X-HE-Tag: 1740050924-371679 X-HE-Meta: U2FsdGVkX18ICjMEmg2YfEKX00KO0zGhM74h282/PEF+EAw4Uy2STXm6yBmDRdmwaStEwIIsdfmff12qskc2g0jw+SjokbxPwOl9H03irMnvcgMwGwgnItWoQT7I4h+WnoWjVj2/mK3Ge9fnMgXaRhgvqPIcc6E19EVUolVNM7MEjBQw2a4Gc50bpseVsUp/uOBTGhEPNz/pu6xaFgeaPAmmUZH6ZvfwKHuFpDtpn1aeK4H9Zx/yQrJCGPQ5tngAmVZJmcMTTLzfDnHwgYKKVgYXQPiJTy+Z/OaPblBpSjY6H4O/G/PDqAGvq9MiEmSHvp0Saf4J0WpjRXR10P3HWwcYA1eTFigFZVhj2QsEecmCyWcdLFeyeP6Ist53nHJvpXJzj3cw06qoZNxDeTBKh5YSv5mxEiYYdxFsa8IK+Erscdf/eyDmWwmqLtwTunB7DC2sOtwbOuR70wMm8YxsZMayqX9EzsNT8UIfHes8MP38d9wNkCaG6OBdXMESKTfx25hEuq/J1T1JzIhRxJGShLFKl0ZC6prcYAFIr1HbtJZut1BHcSQwyyIPXcONCURbxvXoIxhx5gsDFBRpAr7/k99+FEIt5CfDF2HFCBITipT48c6TpuOwK3zERgGFtWnFFe6KIR8j0uElXCFCEd7aHckzNu0r5J3V5kVspFiytcBvawNF+6lnlX8tYAzh4MTPo9c8B+WkAaUEPJSYdAtS+xQUH1WaE9pWgt3pHolgnafr8UwDmeqEpWCVl2B3STPhJrbqhqMEIZgu+tn8bd77p5LIsM86J37EaYjGhasON/pfxgw3KBg3Zzg5ZV5opc8hh0y60Ijs1A2FmOZDZ8gQY70LFnpp5MiZkFLW+HfphyUdtfdOOYAKMw4j6cR8F0NaZ+6ZLbkYKVl6OaAuSvbu/Zn+SMOnJey92SvxI2yt/+e/9qSX8r+8qdzdous05CxZ9jYu6OmwmO5i0o8mdYw +EFANq4L SNfw42Z59qKyBAP2EBuGYT47uVH0itJyhNvx2axcLP4SoKkV5D+JIsiQ62qfDFXrqe8oHuT4FPcbbpYJmKikGeY8njQrQyIof0rhC+81ETFG0q0nJkEw/ehLehsuks9bX/om4gnjzwqhDowzT4KkOtB2G7H7iL12lzzyWkY5mKx1WKIOZNUyWEggdeN0sH1qkaTfr0mlRYJXqYvQJNIy5jDpVJJr30XTvLX+Lk4m3mn3+nM7+iMsAGxPHXCNAn8lnGSUbs7tUBvsn+xjcLJpe1LujTvcE93GGqQ83SlQsy5yGdpY3RP3VgZFzH+ZY2ROR057O6Zct22VtZSrte29RulKPrdJvNzSOg0yjQSahxzYA8uxG6cWfq4iPDSA3lKokxcl0Sp3hvWqrRiYb9TDCvGPkxBqf1OuLKo5mZ9fj50nmJ+W0suMiE5UImx9NDcO2S1n17BKXpKUxuhQ2g76oMedGYA== 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 2/20/25 12:25, David Hildenbrand wrote: > On 11.02.25 13:11, Fuad Tabba wrote: >> Before transitioning a guest_memfd folio to unshared, thereby >> disallowing access by the host and allowing the hypervisor to >> transition its view of the guest page as private, we need to be >> sure that the host doesn't have any references to the folio. >> >> This patch introduces a new type for guest_memfd folios, which >> isn't activated in this series but is here as a placeholder and >> to facilitate the code in the next patch. This will be used in >> the future to register a callback that informs the guest_memfd >> subsystem when the last reference is dropped, therefore knowing >> that the host doesn't have any remaining references. >> >> Signed-off-by: Fuad Tabba >> --- > > [...] > >> static const char *page_type_name(unsigned int page_type) >> diff --git a/mm/swap.c b/mm/swap.c >> index 47bc1bb919cc..241880a46358 100644 >> --- a/mm/swap.c >> +++ b/mm/swap.c >> @@ -38,6 +38,10 @@ >> #include >> #include >> >> +#ifdef CONFIG_KVM_GMEM_SHARED_MEM >> +#include >> +#endif >> + >> #include "internal.h" >> >> #define CREATE_TRACE_POINTS >> @@ -101,6 +105,11 @@ static void free_typed_folio(struct folio *folio) >> case PGTY_hugetlb: >> free_huge_folio(folio); >> return; >> +#endif >> +#ifdef CONFIG_KVM_GMEM_SHARED_MEM >> + case PGTY_guestmem: >> + kvm_gmem_handle_folio_put(folio); >> + return; > > Hm, if KVM is built as a module, will that work? Or would we need the Good catch, I guess not? > core-mm guest_memfd shim that would always be compiled into the core and > decouple KVM from guest_memfd ("library")? That could also help avoid exporting the mpol symbols in the NUMA mempolicy series?