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 9BFA6C83F22 for ; Tue, 15 Jul 2025 09:34:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C94ED6B00AF; Tue, 15 Jul 2025 05:34:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C44F46B00B0; Tue, 15 Jul 2025 05:34:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B0D9F6B00B1; Tue, 15 Jul 2025 05:34:33 -0400 (EDT) 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 9E5146B00AF for ; Tue, 15 Jul 2025 05:34:33 -0400 (EDT) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 5AE961D9F85 for ; Tue, 15 Jul 2025 09:34:33 +0000 (UTC) X-FDA: 83665988826.16.44F4EC9 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) by imf09.hostedemail.com (Postfix) with ESMTP id 7223514000C for ; Tue, 15 Jul 2025 09:34:31 +0000 (UTC) Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=fNtd103c; spf=pass (imf09.hostedemail.com: domain of 3piB2aAUKCAs4lmmlrzzrwp.nzxwty58-xxv6lnv.z2r@flex--tabba.bounces.google.com designates 209.85.128.74 as permitted sender) smtp.mailfrom=3piB2aAUKCAs4lmmlrzzrwp.nzxwty58-xxv6lnv.z2r@flex--tabba.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1752572071; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=47rVlr8Uc/SdJ5Y2yETdFZUDua/sXacoe643TNgwpkI=; b=EHTsCe4hRoQcyaHp1GafD3GI6yDg2qi5isQR5lQFqJi4sCgrcKKgkVwxpLqC9N7/JkEKFm e6tyWsTofRPzg4goxTeLQgQVppB7F945bFpV6D0IaaSuaC86tI+b5qaT4R0G/L0c/Av5Ta T8ogV8zjRHex0kRX/jSmrURa2oL6to0= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=fNtd103c; spf=pass (imf09.hostedemail.com: domain of 3piB2aAUKCAs4lmmlrzzrwp.nzxwty58-xxv6lnv.z2r@flex--tabba.bounces.google.com designates 209.85.128.74 as permitted sender) smtp.mailfrom=3piB2aAUKCAs4lmmlrzzrwp.nzxwty58-xxv6lnv.z2r@flex--tabba.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1752572071; a=rsa-sha256; cv=none; b=FL6J+hpjukL3IhdEnGSREhn6XYyQYgiZNMTAobdNOVrvxhe72QLOjsiwMpkoFKYY4nAo4Q 4I+p/vuCaxt04XGx799ZUGeC1ecTDk1qZDqUal4J+ySu5/5foaHenBwCf+cj469tLL/4Rg tAICz5qmOR+IK/3StLoOsazfuEZ1ESI= Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-455ea9cb0beso30145595e9.0 for ; Tue, 15 Jul 2025 02:34:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1752572070; x=1753176870; darn=kvack.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=47rVlr8Uc/SdJ5Y2yETdFZUDua/sXacoe643TNgwpkI=; b=fNtd103cGhZ9fQbtFQ+XaeAHCBY7YICuHfI+/TAWZR6G5Mgdx2N4+GnVHrscIjUdLF or46v3ci0u7CA4KVzJu4t+pNomjgZD1BnUpI1VrAIgNHWXX9QGuwFHfYrC3FTPpIn/od 7AW/SgTAgtWbVCa4BAISngkwlQwaMhTN82eIEja/5Oaa+tx4XnB8+xyxSuLvO26YknmB HDys9jlcZ1lWbMhzdHr83mW29NzUU7LeaGirFiy/lgmyU8g25O43MrnOeUSyO7Np1dRK U0qUP4nBXDnATsDF8Ya0ceWiVXCHdVAFr2ZwC9rFdcRICqzqSkf4wbzgCvAjocAxRLrZ pFow== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1752572070; x=1753176870; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=47rVlr8Uc/SdJ5Y2yETdFZUDua/sXacoe643TNgwpkI=; b=Zu0MHmEhJaEyTw+3y42O8EE+4LnyW/V8TXyK9YJ2ZhtKDcH9kG2KQ0B1jLayv7k8ZE ppqIHzvMsWJPP1zel7dovYmNDUCnqwo001jDqZpUVm4yDLHOL+a49fD8Ky2bvbWJTCqX MVz+jUhNJ6IAKWH4l0CnN4tp3OeD9v+IKVOn0XmtwvJ4EwA7EE98KnHMC+N6c0CodCw7 kA0++kXaLFYjF/54dk2IAshINHWIb4QRDNGP3vXnw5kdH3BF4KUaISmjSqReERMIZjec QxSDivSlFSYxcaVfEz1LCnL4ftT108zalVncKI4iLGZr2Idq9+1fnXPItsnK6kz5NN39 98rQ== X-Forwarded-Encrypted: i=1; AJvYcCUe9F31ZWHj+7HTuac4lc89IJPOZoWTHHwGMrum2MngOcHhYDUaXdwW19zpa7X+4MrhAVqHONGVKQ==@kvack.org X-Gm-Message-State: AOJu0YxWWvjdr9YWL6OpWI+2gLaAtmZnlhemdQQ/uPDXJml6OsnnvRDO Cu/prz0Bi3LAiPwvIbyR8PfChyhAZxEnccVhf23rnja232h6/8Lsc5PXKkSo/hAOx/3kEHCF3Ko r6g== X-Google-Smtp-Source: AGHT+IGZGGp1NFdrhGIBj0xIFeHETS5Eg5RNZf/7w6Lo5N/3yqifjyWC27FTYp2tf115ynIZyMvpUL2uow== X-Received: from wmbdr14.prod.google.com ([2002:a05:600c:608e:b0:456:15bd:a297]) (user=tabba job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:3b17:b0:455:fc16:9eb3 with SMTP id 5b1f17b1804b1-455fc16a2ccmr100761475e9.33.1752572070039; Tue, 15 Jul 2025 02:34:30 -0700 (PDT) Date: Tue, 15 Jul 2025 10:33:47 +0100 In-Reply-To: <20250715093350.2584932-1-tabba@google.com> Mime-Version: 1.0 References: <20250715093350.2584932-1-tabba@google.com> X-Mailer: git-send-email 2.50.0.727.gbf7dc18ff4-goog Message-ID: <20250715093350.2584932-19-tabba@google.com> Subject: [PATCH v14 18/21] KVM: arm64: Enable host mapping of shared guest_memfd memory From: Fuad Tabba To: kvm@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-mm@kvack.org, kvmarm@lists.linux.dev 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, isaku.yamahata@intel.com, mic@digikod.net, vbabka@suse.cz, vannapurve@google.com, ackerleytng@google.com, mail@maciej.szmigiero.name, david@redhat.com, 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, peterx@redhat.com, pankaj.gupta@amd.com, ira.weiny@intel.com, tabba@google.com Content-Type: text/plain; charset="UTF-8" X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 7223514000C X-Stat-Signature: fkpw6qxsck6di8e1yf5ce3uaroq3ao7o X-HE-Tag: 1752572071-313959 X-HE-Meta: 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 E4iauemo 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 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: Enable host userspace mmap support for guest_memfd-backed memory on arm64. This change provides arm64 with the capability to map guest memory at the host directly from guest_memfd: * Define kvm_arch_supports_gmem_mmap() for arm64: The kvm_arch_supports_gmem_mmap() macro is defined for arm64 to be true if CONFIG_KVM_GMEM_SUPPORTS_MMAP is enabled. For existing arm64 KVM VM types that support guest_memfd, this enables them to use guest_memfd with host userspace mappings. This provides a consistent behavior as there are currently no arm64 CoCo VMs that rely on guest_memfd solely for private, non-mappable memory. Future arm64 VM types can override or restrict this behavior via the kvm_arch_supports_gmem_mmap() hook if needed. * Select CONFIG_KVM_GMEM_SUPPORTS_MMAP in arm64 Kconfig. * Enforce KVM_MEMSLOT_GMEM_ONLY for guest_memfd on arm64: Checks are added to ensure that if guest_memfd is enabled on arm64, KVM_GMEM_SUPPORTS_MMAP must also be enabled. This means guest_memfd-backed memory slots on arm64 are currently only supported if they are intended for shared memory use cases (i.e., kvm_memslot_is_gmem_only() is true). This design reflects the current arm64 KVM ecosystem where guest_memfd is primarily being introduced for VMs that support shared memory. Reviewed-by: James Houghton Reviewed-by: Gavin Shan Acked-by: David Hildenbrand Signed-off-by: Fuad Tabba --- arch/arm64/include/asm/kvm_host.h | 4 ++++ arch/arm64/kvm/Kconfig | 2 ++ arch/arm64/kvm/mmu.c | 7 +++++++ 3 files changed, 13 insertions(+) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 3e41a880b062..63f7827cfa1b 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1674,5 +1674,9 @@ void compute_fgu(struct kvm *kvm, enum fgt_group_id fgt); void get_reg_fixed_bits(struct kvm *kvm, enum vcpu_sysreg reg, u64 *res0, u64 *res1); void check_feature_map(void); +#ifdef CONFIG_KVM_GMEM +#define kvm_arch_supports_gmem(kvm) true +#define kvm_arch_supports_gmem_mmap(kvm) IS_ENABLED(CONFIG_KVM_GMEM_SUPPORTS_MMAP) +#endif #endif /* __ARM64_KVM_HOST_H__ */ diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index 713248f240e0..323b46b7c82f 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -37,6 +37,8 @@ menuconfig KVM select HAVE_KVM_VCPU_RUN_PID_CHANGE select SCHED_INFO select GUEST_PERF_EVENTS if PERF_EVENTS + select KVM_GMEM + select KVM_GMEM_SUPPORTS_MMAP help Support hosting virtualized guest machines. diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 8c82df80a835..85559b8a0845 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -2276,6 +2276,13 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, if ((new->base_gfn + new->npages) > (kvm_phys_size(&kvm->arch.mmu) >> PAGE_SHIFT)) return -EFAULT; + /* + * Only support guest_memfd backed memslots with mappable memory, since + * there aren't any CoCo VMs that support only private memory on arm64. + */ + if (kvm_slot_has_gmem(new) && !kvm_memslot_is_gmem_only(new)) + return -EINVAL; + hva = new->userspace_addr; reg_end = hva + (new->npages << PAGE_SHIFT); -- 2.50.0.727.gbf7dc18ff4-goog