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 BC176F459F3 for ; Fri, 10 Apr 2026 15:19:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2D4CA6B00A9; Fri, 10 Apr 2026 11:19:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 285C76B00AC; Fri, 10 Apr 2026 11:19:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 153CD6B00A9; Fri, 10 Apr 2026 11:19:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 012186B00A9 for ; Fri, 10 Apr 2026 11:19:29 -0400 (EDT) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 8A4691402CF for ; Fri, 10 Apr 2026 15:19:29 +0000 (UTC) X-FDA: 84643005258.20.6464FE4 Received: from iad-out-009.esa.us-east-1.outbound.mail-perimeter.amazon.com (iad-out-009.esa.us-east-1.outbound.mail-perimeter.amazon.com [34.198.94.229]) by imf11.hostedemail.com (Postfix) with ESMTP id 4048640013 for ; Fri, 10 Apr 2026 15:19:27 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=amazon.co.uk header.s=amazoncorp2 header.b=UIYadv7D; dmarc=pass (policy=quarantine) header.from=amazon.co.uk; spf=pass (imf11.hostedemail.com: domain of "prvs=5539d40d4=kalyazin@amazon.co.uk" designates 34.198.94.229 as permitted sender) smtp.mailfrom="prvs=5539d40d4=kalyazin@amazon.co.uk" ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1775834367; a=rsa-sha256; cv=none; b=4kipWjGpKmlkQ47vDI9KCYdDWfdiewZjOllHMWZMdIwxVU41RFvBp8EHp4S684Ex+qgZIM CreOp7Ftt4sr+4jkU2/qX/Y/vw1gFtXYOes/RprPDAWthsgZIvmDww2bfjnQVyoe0G+rMD HaOlDQLAutdjc3ilo338ygl0wzbIFRg= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=amazon.co.uk header.s=amazoncorp2 header.b=UIYadv7D; dmarc=pass (policy=quarantine) header.from=amazon.co.uk; spf=pass (imf11.hostedemail.com: domain of "prvs=5539d40d4=kalyazin@amazon.co.uk" designates 34.198.94.229 as permitted sender) smtp.mailfrom="prvs=5539d40d4=kalyazin@amazon.co.uk" ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1775834367; 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=vLy8Uo7H/yy1MpTCKNu3B0dgocKjoo20PjX7Wqklm/o=; b=8JAZX/XKiXxggExSTwWJPHTTRaBfKGnk09ShBhXae5Vx21W6wv2JGWPBMhKgahj6Eju7HN t2LLQaPIYPQCBdHQAJUgxVx/AbdqeG7BnbzmKamcaKt1E4duhnstg5QKzesmj9IYBPquTr MJmavdjwdA+rw0ADh6i2j//Vdh+PkRU= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.co.uk; i=@amazon.co.uk; q=dns/txt; s=amazoncorp2; t=1775834367; x=1807370367; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-transfer-encoding:mime-version; bh=vLy8Uo7H/yy1MpTCKNu3B0dgocKjoo20PjX7Wqklm/o=; b=UIYadv7Dr8CN0XX3jsaJ/xofvzrqwod3k9D4GNUiqLG4GuT7ZXZdNud5 cJDfpNfl60ykBweazbq0vSIdQnvqGFtLHAWjNLJHWBStLRJcwO2P3ZdiV y4FLSPp8r9UiUlD//9oiwVizZufFcWG2fxqY4d1wAYTnBOBBTkoGZ2fx9 50WzostxWXP1TZqwi0rQlF7IiGlNjqJGPXVkAMcC0QHr+zhh9SNQ00hgM OFMKBHeEOXxiW6dkKvS1+Xv9Z/1aUJU5L1JxqzeUNz+8wgWvoDeMbPjj8 IyL9TCAOBYEE7aFUYeSCmyHKLn3bVJxVZVB0x9PV5hSy389SJeaKeWMSK g==; X-CSE-ConnectionGUID: /gJawKxvRtuwf19Z3qd7/g== X-CSE-MsgGUID: DRWm/oHcTk6GTV9npce06w== X-IronPort-AV: E=Sophos;i="6.23,171,1770595200"; d="scan'208";a="15898148" Received: from ip-10-4-10-75.ec2.internal (HELO smtpout.naws.us-east-1.prod.farcaster.email.amazon.dev) ([10.4.10.75]) by internal-iad-out-009.esa.us-east-1.outbound.mail-perimeter.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Apr 2026 15:19:25 +0000 Received: from EX19MTAUEC002.ant.amazon.com [72.21.196.66:19527] by smtpin.naws.us-east-1.prod.farcaster.email.amazon.dev [10.0.29.254:2525] with esmtp (Farcaster) id b9c5cfe8-25a6-4ec1-9c9f-bb40ee7f6229; Fri, 10 Apr 2026 15:19:25 +0000 (UTC) X-Farcaster-Flow-ID: b9c5cfe8-25a6-4ec1-9c9f-bb40ee7f6229 Received: from EX19D027UEC001.ant.amazon.com (10.252.137.156) by EX19MTAUEC002.ant.amazon.com (10.252.135.253) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.37; Fri, 10 Apr 2026 15:19:25 +0000 Received: from EX19D027UEC003.ant.amazon.com (10.252.137.250) by EX19D027UEC001.ant.amazon.com (10.252.137.156) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.37; Fri, 10 Apr 2026 15:19:24 +0000 Received: from EX19D027UEC003.ant.amazon.com ([fe80::887f:519b:ba73:21d]) by EX19D027UEC003.ant.amazon.com ([fe80::887f:519b:ba73:21d%3]) with mapi id 15.02.2562.037; Fri, 10 Apr 2026 15:19:24 +0000 From: "Kalyazin, Nikita" To: "kvm@vger.kernel.org" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "kvmarm@lists.linux.dev" , "linux-fsdevel@vger.kernel.org" , "linux-mm@kvack.org" , "bpf@vger.kernel.org" , "linux-kselftest@vger.kernel.org" , "kernel@xen0n.name" , "linux-riscv@lists.infradead.org" , "linux-s390@vger.kernel.org" , "loongarch@lists.linux.dev" , "linux-pm@vger.kernel.org" CC: "pbonzini@redhat.com" , "corbet@lwn.net" , "maz@kernel.org" , "oupton@kernel.org" , "joey.gouly@arm.com" , "suzuki.poulose@arm.com" , "yuzenghui@huawei.com" , "catalin.marinas@arm.com" , "will@kernel.org" , "seanjc@google.com" , "tglx@kernel.org" , "mingo@redhat.com" , "bp@alien8.de" , "dave.hansen@linux.intel.com" , "x86@kernel.org" , "hpa@zytor.com" , "luto@kernel.org" , "peterz@infradead.org" , "willy@infradead.org" , "akpm@linux-foundation.org" , "david@kernel.org" , "lorenzo.stoakes@oracle.com" , "vbabka@kernel.org" , "rppt@kernel.org" , "surenb@google.com" , "mhocko@suse.com" , "ast@kernel.org" , "daniel@iogearbox.net" , "andrii@kernel.org" , "martin.lau@linux.dev" , "eddyz87@gmail.com" , "song@kernel.org" , "yonghong.song@linux.dev" , "john.fastabend@gmail.com" , "kpsingh@kernel.org" , "sdf@fomichev.me" , "haoluo@google.com" , "jolsa@kernel.org" , "jgg@ziepe.ca" , "jhubbard@nvidia.com" , "peterx@redhat.com" , "jannh@google.com" , "pfalcato@suse.de" , "skhan@linuxfoundation.org" , "riel@surriel.com" , "ryan.roberts@arm.com" , "jgross@suse.com" , "yu-cheng.yu@intel.com" , "kas@kernel.org" , "coxu@redhat.com" , "ackerleytng@google.com" , "yosry@kernel.org" , "ajones@ventanamicro.com" , "maobibo@loongson.cn" , "tabba@google.com" , "prsampat@amd.com" , "wu.fei9@sanechips.com.cn" , "mlevitsk@redhat.com" , "jmattson@google.com" , "jthoughton@google.com" , "agordeev@linux.ibm.com" , "alex@ghiti.fr" , "aou@eecs.berkeley.edu" , "borntraeger@linux.ibm.com" , "chenhuacai@kernel.org" , "baolu.lu@linux.intel.com" , "dev.jain@arm.com" , "gor@linux.ibm.com" , "hca@linux.ibm.com" , "palmer@dabbelt.com" , "pjw@kernel.org" , "shijie@os.amperecomputing.com" , "svens@linux.ibm.com" , "thuth@redhat.com" , "yang@os.amperecomputing.com" , "Liam.Howlett@oracle.com" , "urezki@gmail.com" , "zhengqi.arch@bytedance.com" , "gerald.schaefer@linux.ibm.com" , "jiayuan.chen@shopee.com" , "lenb@kernel.org" , "pavel@kernel.org" , "rafael@kernel.org" , "yangyicong@hisilicon.com" , "vannapurve@google.com" , "jackmanb@google.com" , "patrick.roy@linux.dev" , "Thomson, Jack" , "Itazuri, Takahiro" , "Manwaring, Derek" , "Kalyazin, Nikita" Subject: [PATCH v12 09/16] KVM: arm64: define kvm_arch_gmem_supports_no_direct_map() Thread-Topic: [PATCH v12 09/16] KVM: arm64: define kvm_arch_gmem_supports_no_direct_map() Thread-Index: AQHcyP1pqKPFicKVfkONXJiuCe9SiA== Date: Fri, 10 Apr 2026 15:19:24 +0000 Message-ID: <20260410151746.61150-10-kalyazin@amazon.com> References: <20260410151746.61150-1-kalyazin@amazon.com> In-Reply-To: <20260410151746.61150-1-kalyazin@amazon.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [172.19.103.116] Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-Rspamd-Queue-Id: 4048640013 X-Stat-Signature: 6q7m14xfr1hd9m4xsb973sutgyt1rs39 X-Rspam-User: X-Rspamd-Server: rspam04 X-HE-Tag: 1775834367-802668 X-HE-Meta: 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 W6ioK5wM 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Patrick Roy =0A= =0A= Support for GUEST_MEMFD_FLAG_NO_DIRECT_MAP on arm64 depends on 1) direct=0A= map manipulations at 4k granularity being possible, and 2) FEAT_S2FWB.=0A= =0A= 1) is met whenever the direct map is set up at 4k granularity (e.g. not=0A= with huge/gigantic pages) at boottime, as due to ARM's=0A= break-before-make semantics, breaking huge mappings into 4k mappings in=0A= the direct map is not possible (BBM would require temporary invalidation=0A= of the entire huge mapping, even if only a 4k subrange should be zapped,=0A= which will probably crash the kernel). However, the current default for=0A= rodata_full is true, which forces a 4k direct map.=0A= =0A= 2) is required to allow KVM to elide cache coherency operations when=0A= installing stage 2 page tables, which require the direct map to be=0A= entry for the newly mapped memory to be present (which it will not be,=0A= as guest_memfd would have removed direct map entries in=0A= kvm_gmem_get_pfn()).=0A= =0A= Cc: Will Deacon =0A= Signed-off-by: Patrick Roy =0A= Reviewed-by: David Hildenbrand (Arm) =0A= Signed-off-by: Nikita Kalyazin =0A= ---=0A= arch/arm64/include/asm/kvm_host.h | 13 +++++++++++++=0A= 1 file changed, 13 insertions(+)=0A= =0A= diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm= _host.h=0A= index 70cb9cfd760a..fbdd43e7e94e 100644=0A= --- a/arch/arm64/include/asm/kvm_host.h=0A= +++ b/arch/arm64/include/asm/kvm_host.h=0A= @@ -19,6 +19,7 @@=0A= #include =0A= #include =0A= #include =0A= +#include =0A= #include =0A= #include =0A= #include =0A= @@ -1682,6 +1683,18 @@ static __always_inline enum fgt_group_id __fgt_reg_t= o_group_id(enum vcpu_sysreg=0A= \=0A= p; \=0A= })=0A= +#ifdef CONFIG_KVM_GUEST_MEMFD=0A= +static inline bool kvm_arch_gmem_supports_no_direct_map(struct kvm *kvm)= =0A= +{=0A= + /*=0A= + * Without FWB, direct map access is needed in kvm_pgtable_stage2_map(),= =0A= + * as it calls dcache_clean_inval_poc().=0A= + */=0A= + return can_set_direct_map() && cpus_have_final_cap(ARM64_HAS_STAGE2_FWB);= =0A= +}=0A= +#define kvm_arch_gmem_supports_no_direct_map kvm_arch_gmem_supports_no_dir= ect_map=0A= +#endif /* CONFIG_KVM_GUEST_MEMFD */=0A= +=0A= =0A= long kvm_get_cap_for_kvm_ioctl(unsigned int ioctl, long *ext);=0A= =0A= -- =0A= 2.50.1=0A= =0A=