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 6111B2BE7D1; Sat, 23 May 2026 00:18:05 +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=1779495485; cv=none; b=hrxx6yt/zO+OVY1yNOrO1hYTjawaFXTRPtrnnWDHsqNu5Bw2EQ9gkqwmsaCcqI8l3ZOTMeGp+HN8/h+U3DV6AZhUOvSLZnczZKtyXTuuqqQEAhr+LLE5vnMNXq+N/DfT07u7eTxpnyWThZm70VsmkhT1vtakcAG/cYWt8Ge3yuo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779495485; c=relaxed/simple; bh=C39lMwHCMaKdkBXuqytsqBdOXv7LJpVv+e8DmDVzfNk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=mjogvOGcIquJ62hCI06jF70WWtKY2fS6DYx18gCs242gg91Ut5VQovXsiRGySfnWvBGLbutR06um24eVRMVWh3wR44BSUFmzZWwlD6JBFO7lk+x5T4m59UWMT2j8oQUY2pByAmSdFXrOauhFgU4pU7zkuH+Wluw5wy3oXiwBPns= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JBd4EZS2; 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="JBd4EZS2" Received: by smtp.kernel.org (Postfix) with ESMTPS id CFD16C32781; Sat, 23 May 2026 00:18:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1779495484; bh=C39lMwHCMaKdkBXuqytsqBdOXv7LJpVv+e8DmDVzfNk=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=JBd4EZS2w3MB6TCIYaisGdZa6GvUMtqZ6EyRGe680xeWL9o/AnCaiIlql3s4HVzUN ZFC+EPixW4x1SAmepkSiu3XjUpkPaOBYqE+nii9B6sWYK1ulx4ntoMfKZ0fF6Tab+D aJKQoSjqWlnaF08jHyTDWRowXJxqIyduN0AEfxIu8JShCnzun9gFLPW01px6tmkLIa nqbXIGqeVP2vo552rePn7yZXhSnbUjCa1Ni3q0ftac1j9odscS8PspjewpJI5/9tZF CasECvHoaudHxqyzqK5krowNZ1dIP3mlj7Zok6c8zJFxuopPg3LZPo88eqzazSnchK YayCdZ4+6H4ZQ== 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 BA096CD5BBA; Sat, 23 May 2026 00:18:04 +0000 (UTC) From: Ackerley Tng via B4 Relay Date: Fri, 22 May 2026 17:18:00 -0700 Subject: [PATCH v7 18/42] KVM: Let userspace disable per-VM mem attributes, enable per-gmem attributes 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" Content-Transfer-Encoding: 7bit Message-Id: <20260522-gmem-inplace-conversion-v7-18-2f0fae496530@google.com> References: <20260522-gmem-inplace-conversion-v7-0-2f0fae496530@google.com> In-Reply-To: <20260522-gmem-inplace-conversion-v7-0-2f0fae496530@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=1779495480; l=2855; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=W0ThPVvBbw9pVumfhkjiMDvxR45g3Paz0SwoTcwuSAg=; b=0lISKKF2QsxRXk6UOczMC8Vk6uGfm+WY+5BLPPA4XeXcN1/XxESDm+WpcgQ64ZPx1vsaizgwh 77f3L1FI0boAuRtK6+xAKJ/qh9RMCd59o1LvqPhQMUrFcQ84llDrmev 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)); -- 2.54.0.794.g4f17f83d09-goog