From nobody Thu Dec 18 10:37:38 2025 Received: from fra-out-009.esa.eu-central-1.outbound.mail-perimeter.amazon.com (fra-out-009.esa.eu-central-1.outbound.mail-perimeter.amazon.com [3.64.237.68]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B398C348886; Fri, 5 Dec 2025 16:59:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=3.64.237.68 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764954003; cv=none; b=r5tz+Y4EUZaE7K4py5QlG6VDP40Uzgo3QF7vX6Lrk2xe6xrvlk469xGrbfYYcSqoGZIhmsLHBtBf6Fok64rNpOTKGG+fRZLfhjY9h7meEHuaycsKaVOXvdRJplm8NIa6vjufDEvetHlMaNPyel15b2reZaVcCkKb9EZ54gaB40s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764954003; c=relaxed/simple; bh=52mHrkP05gYzT147dW4uInww81IpjV4wn8Xsu+UrgMw=; h=From:To:CC:Subject:Date:Message-ID:References:In-Reply-To: Content-Type:MIME-Version; b=pK0yIPl0n6vBXYJtMpminM20X9fvcD9efoA54t+0K0uiitcFV4ka8IWit0YMv0fki7mE/CGHTBFaZ3AdFb5bzw4bmfD5gdLA+V5pEXGsPt/jaZOrytx7TPEgLoq371vJXr4I3c5VVWKrL1kxfLEvtC8vyPRqkrCtWDShQ2z3zD0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.co.uk; spf=pass smtp.mailfrom=amazon.co.uk; dkim=pass (2048-bit key) header.d=amazon.co.uk header.i=@amazon.co.uk header.b=LkpHFV9v; arc=none smtp.client-ip=3.64.237.68 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.co.uk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.co.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=amazon.co.uk header.i=@amazon.co.uk header.b="LkpHFV9v" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.co.uk; i=@amazon.co.uk; q=dns/txt; s=amazoncorp2; t=1764953998; x=1796489998; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-transfer-encoding:mime-version; bh=OprfmizXxq8RRTSlSSc6Z/sKanOls1Ur59Qhbz1MdVc=; b=LkpHFV9v/Yt04CZIHYyAIQPsIUeVyM2p/yJAaaKoQ/VUpgLi7e+xK5zO s4DScDKAOMTwVTja5uvmXfdDkI1YH63ghvmQSedRJA/Xg4s94Wp72R7vv UyT8D+MEXMZQXizShO9yQ/ZYEYuvEqmkh1nDOFK3tiBmpPv0Sm3ZFJ/4V vTKl1zp+NLFpziLiBlLg26DAP84y08sfixeFHRR5tjr5kjCB45kwC0X5S iC4XIJwFkBPMHCMd67Xk8clE7GAI0MYBywXQgN198P/mKEc4/WOpFQf0y eBt6dq9kHq5m7WcUdpQRL1uI/O/7dSRqfXnfJ9ohdWW5PQDNTIgEZUNGE A==; X-CSE-ConnectionGUID: wdWaJSd5SF6NQona6voUBg== X-CSE-MsgGUID: mLPb0a/XSKCaS9kn1GTYnw== X-IronPort-AV: E=Sophos;i="6.20,252,1758585600"; d="scan'208";a="6206137" Received: from ip-10-6-3-216.eu-central-1.compute.internal (HELO smtpout.naws.eu-central-1.prod.farcaster.email.amazon.dev) ([10.6.3.216]) by internal-fra-out-009.esa.eu-central-1.outbound.mail-perimeter.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Dec 2025 16:59:49 +0000 Received: from EX19MTAEUB002.ant.amazon.com [54.240.197.232:11504] by smtpin.naws.eu-central-1.prod.farcaster.email.amazon.dev [10.0.24.148:2525] with esmtp (Farcaster) id 34fe6e69-dd5b-4480-b95e-ddc8757a2feb; Fri, 5 Dec 2025 16:59:49 +0000 (UTC) X-Farcaster-Flow-ID: 34fe6e69-dd5b-4480-b95e-ddc8757a2feb Received: from EX19D005EUB002.ant.amazon.com (10.252.51.103) by EX19MTAEUB002.ant.amazon.com (10.252.51.79) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.29; Fri, 5 Dec 2025 16:59:41 +0000 Received: from EX19D005EUB003.ant.amazon.com (10.252.51.31) by EX19D005EUB002.ant.amazon.com (10.252.51.103) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.29; Fri, 5 Dec 2025 16:59:40 +0000 Received: from EX19D005EUB003.ant.amazon.com ([fe80::b825:becb:4b38:da0c]) by EX19D005EUB003.ant.amazon.com ([fe80::b825:becb:4b38:da0c%3]) with mapi id 15.02.2562.029; Fri, 5 Dec 2025 16:59:40 +0000 From: "Kalyazin, Nikita" To: "kvm@vger.kernel.org" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "kvmarm@lists.linux.dev" , "linux-fsdevel@vger.kernel.org" , "linux-mm@kvack.org" , "bpf@vger.kernel.org" , "linux-kselftest@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@linutronix.de" , "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" , "Liam.Howlett@oracle.com" , "vbabka@suse.cz" , "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" , "shuah@kernel.org" , "riel@surriel.com" , "baohua@kernel.org" , "ryan.roberts@arm.com" , "jgross@suse.com" , "yu-cheng.yu@intel.com" , "kas@kernel.org" , "coxu@redhat.com" , "kevin.brodsky@arm.com" , "ackerleytng@google.com" , "maobibo@loongson.cn" , "prsampat@amd.com" , "mlevitsk@redhat.com" , "isaku.yamahata@intel.com" , "jmattson@google.com" , "jthoughton@google.com" , "linux-arm-kernel@lists.infradead.org" , "vannapurve@google.com" , "jackmanb@google.com" , "aneesh.kumar@kernel.org" , "patrick.roy@linux.dev" , "Thomson, Jack" , "Itazuri, Takahiro" , "Manwaring, Derek" , "Cali, Marco" , "Kalyazin, Nikita" Subject: [PATCH v8 10/13] KVM: selftests: Add guest_memfd based vm_mem_backing_src_types Thread-Topic: [PATCH v8 10/13] KVM: selftests: Add guest_memfd based vm_mem_backing_src_types Thread-Index: AQHcZgiLyS0oCQO1nUODCs70+4I+GA== Date: Fri, 5 Dec 2025 16:59:40 +0000 Message-ID: <20251205165743.9341-11-kalyazin@amazon.com> References: <20251205165743.9341-1-kalyazin@amazon.com> In-Reply-To: <20251205165743.9341-1-kalyazin@amazon.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Patrick Roy Allow selftests to configure their memslots such that userspace_addr is set to a MAP_SHARED mapping of the guest_memfd that's associated with the memslot. This setup is the configuration for non-CoCo VMs, where all guest memory is backed by a guest_memfd whose folios are all marked shared, but KVM is still able to access guest memory to provide functionality such as MMIO emulation on x86. Add backing types for normal guest_memfd, as well as direct map removed guest_memfd. Signed-off-by: Patrick Roy Signed-off-by: Nikita Kalyazin --- .../testing/selftests/kvm/include/kvm_util.h | 18 ++++++ .../testing/selftests/kvm/include/test_util.h | 7 +++ tools/testing/selftests/kvm/lib/kvm_util.c | 61 ++++++++++--------- tools/testing/selftests/kvm/lib/test_util.c | 8 +++ 4 files changed, 65 insertions(+), 29 deletions(-) diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing= /selftests/kvm/include/kvm_util.h index 81f4355ff28a..6689b43810c1 100644 --- a/tools/testing/selftests/kvm/include/kvm_util.h +++ b/tools/testing/selftests/kvm/include/kvm_util.h @@ -641,6 +641,24 @@ static inline bool is_smt_on(void) =20 void vm_create_irqchip(struct kvm_vm *vm); =20 +static inline uint32_t backing_src_guest_memfd_flags(enum vm_mem_backing_s= rc_type t) +{ + uint32_t flags =3D 0; + + switch (t) { + case VM_MEM_SRC_GUEST_MEMFD_NO_DIRECT_MAP: + flags |=3D GUEST_MEMFD_FLAG_NO_DIRECT_MAP; + fallthrough; + case VM_MEM_SRC_GUEST_MEMFD: + flags |=3D GUEST_MEMFD_FLAG_MMAP | GUEST_MEMFD_FLAG_INIT_SHARED; + break; + default: + break; + } + + return flags; +} + static inline int __vm_create_guest_memfd(struct kvm_vm *vm, uint64_t size, uint64_t flags) { diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testin= g/selftests/kvm/include/test_util.h index 8140e59b59e5..ea6de20ce8ef 100644 --- a/tools/testing/selftests/kvm/include/test_util.h +++ b/tools/testing/selftests/kvm/include/test_util.h @@ -152,6 +152,8 @@ enum vm_mem_backing_src_type { VM_MEM_SRC_ANONYMOUS_HUGETLB_16GB, VM_MEM_SRC_SHMEM, VM_MEM_SRC_SHARED_HUGETLB, + VM_MEM_SRC_GUEST_MEMFD, + VM_MEM_SRC_GUEST_MEMFD_NO_DIRECT_MAP, NUM_SRC_TYPES, }; =20 @@ -184,6 +186,11 @@ static inline bool backing_src_is_shared(enum vm_mem_b= acking_src_type t) return vm_mem_backing_src_alias(t)->flag & MAP_SHARED; } =20 +static inline bool backing_src_is_guest_memfd(enum vm_mem_backing_src_type= t) +{ + return t =3D=3D VM_MEM_SRC_GUEST_MEMFD || t =3D=3D VM_MEM_SRC_GUEST_MEMFD= _NO_DIRECT_MAP; +} + static inline bool backing_src_can_be_huge(enum vm_mem_backing_src_type t) { return t !=3D VM_MEM_SRC_ANONYMOUS && t !=3D VM_MEM_SRC_SHMEM; diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/sel= ftests/kvm/lib/kvm_util.c index 56ddbca91850..28ee51253909 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -1013,6 +1013,33 @@ void vm_mem_add(struct kvm_vm *vm, enum vm_mem_backi= ng_src_type src_type, alignment =3D 1; #endif =20 + if (guest_memfd < 0) { + if ((flags & KVM_MEM_GUEST_MEMFD) || backing_src_is_guest_memfd(src_type= )) { + uint32_t guest_memfd_flags =3D backing_src_guest_memfd_flags(src_type); + + TEST_ASSERT(!guest_memfd_offset, + "Offset must be zero when creating new guest_memfd"); + guest_memfd =3D vm_create_guest_memfd(vm, mem_size, guest_memfd_flags); + } + } else { + /* + * Install a unique fd for each memslot so that the fd + * can be closed when the region is deleted without + * needing to track if the fd is owned by the framework + * or by the caller. + */ + guest_memfd =3D kvm_dup(guest_memfd); + } + + if (guest_memfd > 0) { + flags |=3D KVM_MEM_GUEST_MEMFD; + + region->region.guest_memfd =3D guest_memfd; + region->region.guest_memfd_offset =3D guest_memfd_offset; + } else { + region->region.guest_memfd =3D -1; + } + /* * When using THP mmap is not guaranteed to returned a hugepage aligned * address so we have to pad the mmap. Padding is not needed for HugeTLB @@ -1028,10 +1055,13 @@ void vm_mem_add(struct kvm_vm *vm, enum vm_mem_back= ing_src_type src_type, if (alignment > 1) region->mmap_size +=3D alignment; =20 - region->fd =3D -1; - if (backing_src_is_shared(src_type)) + if (backing_src_is_guest_memfd(src_type)) + region->fd =3D guest_memfd; + else if (backing_src_is_shared(src_type)) region->fd =3D kvm_memfd_alloc(region->mmap_size, src_type =3D=3D VM_MEM_SRC_SHARED_HUGETLB); + else + region->fd =3D -1; =20 region->mmap_start =3D kvm_mmap(region->mmap_size, PROT_READ | PROT_WRITE, vm_mem_backing_src_alias(src_type)->flag, @@ -1056,33 +1086,6 @@ void vm_mem_add(struct kvm_vm *vm, enum vm_mem_backi= ng_src_type src_type, } =20 region->backing_src_type =3D src_type; - - if (guest_memfd < 0) { - if (flags & KVM_MEM_GUEST_MEMFD) { - uint32_t guest_memfd_flags =3D 0; - TEST_ASSERT(!guest_memfd_offset, - "Offset must be zero when creating new guest_memfd"); - guest_memfd =3D vm_create_guest_memfd(vm, mem_size, guest_memfd_flags); - } - } else { - /* - * Install a unique fd for each memslot so that the fd - * can be closed when the region is deleted without - * needing to track if the fd is owned by the framework - * or by the caller. - */ - guest_memfd =3D kvm_dup(guest_memfd); - } - - if (guest_memfd > 0) { - flags |=3D KVM_MEM_GUEST_MEMFD; - - region->region.guest_memfd =3D guest_memfd; - region->region.guest_memfd_offset =3D guest_memfd_offset; - } else { - region->region.guest_memfd =3D -1; - } - region->unused_phy_pages =3D sparsebit_alloc(); if (vm_arch_has_protected_memory(vm)) region->protected_phy_pages =3D sparsebit_alloc(); diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/se= lftests/kvm/lib/test_util.c index 8a1848586a85..ce9fe0271515 100644 --- a/tools/testing/selftests/kvm/lib/test_util.c +++ b/tools/testing/selftests/kvm/lib/test_util.c @@ -306,6 +306,14 @@ const struct vm_mem_backing_src_alias *vm_mem_backing_= src_alias(uint32_t i) */ .flag =3D MAP_SHARED, }, + [VM_MEM_SRC_GUEST_MEMFD] =3D { + .name =3D "guest_memfd", + .flag =3D MAP_SHARED, + }, + [VM_MEM_SRC_GUEST_MEMFD_NO_DIRECT_MAP] =3D { + .name =3D "guest_memfd_no_direct_map", + .flag =3D MAP_SHARED, + } }; _Static_assert(ARRAY_SIZE(aliases) =3D=3D NUM_SRC_TYPES, "Missing new backing src types?"); --=20 2.50.1