From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 061DF49550D; Thu, 7 May 2026 20:22:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778185371; cv=none; b=VtwqbzvGBOdLMw8iKQ2G9wF6SWi2rW9PXSZDgo/KoNp4AXs6tvHKu8ea82xx492kwOrSZ2J1mH5S9b0npsT/RGd9GBU3NJBk6vFHxNxcYPOM8R9W4GxAA7atGOsbu7NSUuovdt1PtrIs1y4of2ISgBcqwVy3ILRX5PgEEPYWnCg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778185371; c=relaxed/simple; bh=3Ey26oHjBIStPVcofdxUBpg3KGMQjwyU1xBvE1HXR/Q=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=R5cq4JCEePXDgxkz9aXLhBBV7woNIg9V7eDPL/JqwYUQZtJD2phS0UzERoucyXc/T0hCWY48qGjluXfRsmmwO4oOegU44ocYPVcxjMCSCICfX9jHTHvfynySwMkp1Yh5rQPUYa9psFSAKBfTRRdP2Gi3iygvcVj62LFJkI/D/I8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Gb8C1jBY; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Gb8C1jBY" Received: by smtp.kernel.org (Postfix) with ESMTPS id DB8E5C2BCC9; Thu, 7 May 2026 20:22:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778185370; bh=3Ey26oHjBIStPVcofdxUBpg3KGMQjwyU1xBvE1HXR/Q=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=Gb8C1jBYrCcNvhb+cC1N2B8UsClY2LEckLli6WjImjD7JLxImOdt/tzEeXaoYJ3vd UoY8Ye38gRR9xsueOz+cDl8Xf39TGdOunMk0DLffLVE9kbsZJ18JoP2sP6yHrR9Pvg qBk4CgMgHiHQqACWNkgx8hnhG39raA71JAUyBQn0StNJSCHfNSmd2+3tx/4G0C+KHc 4j4cZFwWoav4xnUEpo+OElX1V/sNKlX07Ruw75xjrx4U4rpjUFJ5b8fZQM+VwkMlo7 XKGKUdkfYUztVreqQIw5A0QYmJ1L2whVj+LuEgBlQm9sXJX3hs9fVh7hZ+gYXlpy9F 3AyC/D1kzp/oQ== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id CC027CD3446; Thu, 7 May 2026 20:22:50 +0000 (UTC) From: Ackerley Tng via B4 Relay Date: Thu, 07 May 2026 13:22:38 -0700 Subject: [PATCH v6 19/43] KVM: Let userspace disable per-VM mem attributes, enable per-gmem attributes Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260507-gmem-inplace-conversion-v6-19-91ab5a8b19a4@google.com> References: <20260507-gmem-inplace-conversion-v6-0-91ab5a8b19a4@google.com> In-Reply-To: <20260507-gmem-inplace-conversion-v6-0-91ab5a8b19a4@google.com> To: aik@amd.com, andrew.jones@linux.dev, binbin.wu@linux.intel.com, brauner@kernel.org, chao.p.peng@linux.intel.com, david@kernel.org, ira.weiny@intel.com, jmattson@google.com, jthoughton@google.com, michael.roth@amd.com, oupton@kernel.org, pankaj.gupta@amd.com, qperret@google.com, rick.p.edgecombe@intel.com, rientjes@google.com, shivankg@amd.com, steven.price@arm.com, tabba@google.com, willy@infradead.org, wyihan@google.com, yan.y.zhao@intel.com, forkloop@google.com, pratyush@kernel.org, suzuki.poulose@arm.com, aneesh.kumar@kernel.org, liam@infradead.org, Paolo Bonzini , Sean Christopherson , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Shuah Khan , Shuah Khan , Vishal Annapurve , Andrew Morton , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Youngjun Park , Qi Zheng , Shakeel Butt , Kiryl Shutsemau , Jason Gunthorpe , Vlastimil Babka Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, Ackerley Tng X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1778185365; l=2855; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=C+ZXwAuQ/e98Rs7Di9G1EWrlq6zteRCZz2vi1AClkpI=; b=dp6jCn9ExgjqByTG7kaxpBbRNBGPX7nuFMLB6FJJWILEhdvQnCRngdmKGdljRH2+yoCeSw4BK Y/wktRb6O2yBOVvPb6wUEdVPY4MaXo1fd0+4WQ5Hw96ejsK19n6u44i X-Developer-Key: i=ackerleytng@google.com; a=ed25519; pk=sAZDYXdm6Iz8FHitpHeFlCMXwabodTm7p8/3/8xUxuU= X-Endpoint-Received: by B4 Relay for ackerleytng@google.com/20260225 with auth_id=649 X-Original-From: Ackerley Tng Reply-To: ackerleytng@google.com From: Sean Christopherson Make vm_memory_attributes a module parameter so that userspace can disable the use of memory attributes on the VM level. To avoid inconsistencies in the way memory attributes are tracked in KVM and guest_memfd, the vm_memory_attributes module_param is made read-only (0444). Make CONFIG_KVM_VM_MEMORY_ATTRIBUTES selectable, only for (CoCo) VM types that might use vm_memory_attributes. Signed-off-by: Sean Christopherson Signed-off-by: Ackerley Tng --- arch/x86/kvm/Kconfig | 13 +++++++++---- virt/kvm/kvm_main.c | 1 + 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index b6d65ee664d0f..8b97d341bd33f 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -82,13 +82,20 @@ config KVM_WERROR config KVM_VM_MEMORY_ATTRIBUTES select KVM_MEMORY_ATTRIBUTES - bool + depends on KVM_SW_PROTECTED_VM || KVM_INTEL_TDX || KVM_AMD_SEV + bool "Enable per-VM memory attributes (for CoCo VMs)" + help + Enable support for per-VM memory attributes, which are deprecated in + favor of tracking memory attributes in guest_memfd. Select this if + you need to run CoCo VMs using a VMM that doesn't support guest_memfd + memory attributes. + + If unsure, say N. config KVM_SW_PROTECTED_VM bool "Enable support for KVM software-protected VMs" depends on EXPERT depends on KVM_X86 && X86_64 - select KVM_VM_MEMORY_ATTRIBUTES help Enable support for KVM software-protected VMs. Currently, software- protected VMs are purely a development and testing vehicle for @@ -139,7 +146,6 @@ config KVM_INTEL_TDX bool "Intel Trust Domain Extensions (TDX) support" default y depends on INTEL_TDX_HOST - select KVM_VM_MEMORY_ATTRIBUTES select HAVE_KVM_ARCH_GMEM_POPULATE help Provides support for launching Intel Trust Domain Extensions (TDX) @@ -163,7 +169,6 @@ config KVM_AMD_SEV depends on KVM_AMD && X86_64 depends on CRYPTO_DEV_SP_PSP && !(KVM_AMD=y && CRYPTO_DEV_CCP_DD=m) select ARCH_HAS_CC_PLATFORM - select KVM_VM_MEMORY_ATTRIBUTES select HAVE_KVM_ARCH_GMEM_PREPARE select HAVE_KVM_ARCH_GMEM_INVALIDATE select HAVE_KVM_ARCH_GMEM_POPULATE diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index cec02d68d7039..ba195bb239aaa 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -104,6 +104,7 @@ module_param(allow_unsafe_mappings, bool, 0444); #ifdef CONFIG_KVM_MEMORY_ATTRIBUTES #ifdef CONFIG_KVM_VM_MEMORY_ATTRIBUTES bool vm_memory_attributes = true; +module_param(vm_memory_attributes, bool, 0444); #endif DEFINE_STATIC_CALL_RET0(__kvm_get_memory_attributes, kvm_get_memory_attributes_t); EXPORT_SYMBOL_FOR_KVM_INTERNAL(STATIC_CALL_KEY(__kvm_get_memory_attributes)); -- 2.54.0.563.g4f69b47b94-goog