From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.18]) (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 549F1298CC4; Sat, 10 Oct 2026 03:32:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791603169; cv=none; b=ds3PEd/QNd0kjCIW79I6FvVtqaAXLrYYR8B5eWsJ4a5VX1YjUZcTQt/kM1KAiwF6ckdhmhoZRKOqn2mJBegzW5yWKKHlxCPTd7gWOeEDmIEnYfB63gE3C275IopB6q+Y7HrTAeotbgsf96vLDCeWjr3Y+w1gQs8mqFsrWs4j4+c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791603169; c=relaxed/simple; bh=L1xvLFtuvT5GKWDgJ3c/DJEPvPiVYnbScbik8/+g7n0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Jg/f8Fj9oYhqZl+GB4H1RCaYeCNuhqys+QXVgoRw8eqb7xhLB1DT+kne46fqDxf783sG7/NZTNDWB+gzAut+fGVw5aLZOKBG22heUsZ7+pflRojeUDfdWXd6ZMXmo6av0t0BAH+iWs8jYAeu9q1yHDz8OuUNpxHeJ+FBtEQ73EY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=QuN+CprY; arc=none smtp.client-ip=198.175.65.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="QuN+CprY" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1791603169; x=1823139169; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=L1xvLFtuvT5GKWDgJ3c/DJEPvPiVYnbScbik8/+g7n0=; b=QuN+CprYDK1kgcGcRUFzSUPCPVlz/u6v9Tzf+e9NpCWS0ENHeYJeqJmK kl/XPB+jK3uy9jGKh01gKpOGEEzpAJlB0MTLOLyUIxneDrpiVYp6JP92O SxUptgCZU21KvS4bbFEQ6+Yp+Oyd35QgIrX/6CkJApzQ7lzl4Kz3NkvsR hK9Pm0tujlFYHvEMDWM6NUz6SwCQaLWAX3sWIlTLaV4zajij7kuvqUwDm 2XbmJUOLAvmEHRzAlzauwoupzNI9otXN74Rh6iSqjV1QLewGE+AU1FFnQ 6Y2TMCn7c7VGzJtY4q2vz0wEK0RAULZZYOrB1Voh6l/yrrd1GjwFw6Sw0 w==; X-CSE-ConnectionGUID: 5yvbENDaTWCn9BUJN7udOA== X-CSE-MsgGUID: nkv2gRXGRI+OoqfqqEtBAA== X-IronPort-AV: E=McAfee;i="6800,10657,11930"; a="404479" X-IronPort-AV: E=Sophos;i="6.27,149,1787036400"; d="scan'208";a="404479" Received: from fmviesa013.fm.intel.com ([10.60.135.153]) by orvoesa110.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2026 20:32:48 -0700 X-CSE-ConnectionGUID: 3lYJoxIFQmKA4unwBVQFlg== X-CSE-MsgGUID: h4ITtYXwQ3OYJZS+UVq/lA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,149,1787036400"; d="scan'208";a="2199563" Received: from binbinwu-mobl.ccr.corp.intel.com (HELO [10.124.245.162]) ([10.124.245.162]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2026 20:32:42 -0700 Message-ID: <4d57c0f7-5ed9-4a1f-b401-a1072af5dd6c@linux.intel.com> Date: Sat, 10 Oct 2026 11:32:39 +0800 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v15 13/23] KVM: selftests: Support guest_memfd in-place conversion To: Lisa Wang Cc: Andrew Jones , Ackerley Tng , Chao Gao , Chenyi Qiang , Dave Hansen , Erdem Aktas , Ira Weiny , Isaku Yamahata , Kiryl Shutsemau , linux-kselftest@vger.kernel.org, Paolo Bonzini , "Pratik R. Sampat" , Reinette Chatre , Rick Edgecombe , Roger Wang , Ryan Afranji , Sagi Shahar , Sean Christopherson , Shuah Khan , Xiaoyao Li , Oliver Upton , Jeremiah McReynolds , kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, x86@kernel.org References: <20261001-tdx-selftests-v15-0-7c62a5d8a992@google.com> <20261001-tdx-selftests-v15-13-7c62a5d8a992@google.com> Content-Language: en-US From: Binbin Wu In-Reply-To: <20261001-tdx-selftests-v15-13-7c62a5d8a992@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 10/2/2026 3:37 AM, Lisa Wang wrote: > With guest_memfd in-place conversion, the memory region can be set as > shared, eliminating the need for dual-backed memory. > > By setting the region to shared initially, the KVM selftest framework > can populate the mmap()-ed guest_memfd memory just like any standard > memory provider. > > For CoCo VMs, pages that need to be private are explicitly set to > private before executing the VM. > > Signed-off-by: Lisa Wang > --- > tools/testing/selftests/kvm/lib/kvm_util.c | 20 ++++++++++++++------ > tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c | 6 +++++- > 2 files changed, 19 insertions(+), 7 deletions(-) > > diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c > index 7625908caf21..f474664b5d92 100644 > --- a/tools/testing/selftests/kvm/lib/kvm_util.c > +++ b/tools/testing/selftests/kvm/lib/kvm_util.c > @@ -494,8 +494,10 @@ struct kvm_vm *__vm_create(struct vm_shape shape, u32 nr_runnable_vcpus, > u64 nr_pages = vm_nr_pages_required(shape.mode, nr_runnable_vcpus, > nr_extra_pages); > struct userspace_mem_region *slot0; > + u64 gmem_flags = 0; > struct kvm_vm *vm; > - int i, flags; > + int flags = 0; > + int i; > > kvm_set_files_rlimit(nr_runnable_vcpus); > > @@ -505,14 +507,20 @@ struct kvm_vm *__vm_create(struct vm_shape shape, u32 nr_runnable_vcpus, > vm = ____vm_create(shape); > > /* > - * Force GUEST_MEMFD for the primary memory region if necessary, e.g. > - * for CoCo VMs that require GUEST_MEMFD backed private memory. > + * Force GUEST_MEMFD for the primary memory region if necessary, and > + * initialize it as shared if in-place conversion is supported, so the > + * selftest framework can populate it exactly like other memory > + * providers. > */ > - flags = 0; > - if (is_guest_memfd_required(shape)) > + if (is_guest_memfd_required(shape)) { > flags |= KVM_MEM_GUEST_MEMFD; > + if (kvm_has_gmem_attributes) > + gmem_flags |= GUEST_MEMFD_FLAG_INIT_SHARED | > + GUEST_MEMFD_FLAG_MMAP; > + } > > - vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 0, 0, nr_pages, flags); > + vm_mem_add(vm, VM_MEM_SRC_ANONYMOUS, 0, 0, nr_pages, flags, > + -1, 0, gmem_flags); This is common for both TDX and SNP, does it break SNP? > for (i = 0; i < NR_MEM_REGIONS; i++) > vm->memslots[i] = 0; > > diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c > index e348507a6be8..40ee9b1951c2 100644 > --- a/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c > +++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx_util.c > @@ -23,6 +23,8 @@ void tdx_vm_setup_boot_code_region(struct kvm_vm *vm) > gpa_t gpa; > u8 *hva; > > + if (kvm_has_gmem_attributes) > + gmem_flags |= GUEST_MEMFD_FLAG_INIT_SHARED | GUEST_MEMFD_FLAG_MMAP; > vm_mem_add(vm, VM_MEM_SRC_SHMEM, alloc_gpa, TD_BOOT_CODE_SLOT, > nr_pages, KVM_MEM_GUEST_MEMFD, -1, 0, gmem_flags); > > @@ -44,9 +46,11 @@ void tdx_vm_setup_boot_parameters_region(struct kvm_vm *vm, u32 nr_runnable_vcpu > size_t boot_params_size = sizeof(struct td_boot_parameters) + > nr_runnable_vcpus * sizeof(struct td_per_vcpu_parameters); > int npages = DIV_ROUND_UP(boot_params_size, PAGE_SIZE); > - const u64 gmem_flags = 0; > + u64 gmem_flags = 0; > gpa_t gpa; > > + if (kvm_has_gmem_attributes) > + gmem_flags |= GUEST_MEMFD_FLAG_INIT_SHARED | GUEST_MEMFD_FLAG_MMAP; > vm_mem_add(vm, VM_MEM_SRC_SHMEM, TD_BOOT_PARAMETERS_GPA, > TD_BOOT_PARAMETERS_SLOT, npages, > KVM_MEM_GUEST_MEMFD, -1, 0, gmem_flags); >