From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f201.google.com (mail-pg1-f201.google.com [209.85.215.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A2622336EE9 for ; Fri, 13 Mar 2026 06:13:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773382390; cv=none; b=U1uZFKvmJ1y/4c+M6wzu6xEScAjHqC2n93/wurg1v9myaS/vfGHgYxwBhED51bfUxCcidZntDcmc8ZYOz8MiwbFcbnkms7u73aol/MRK3nYip/M3+kf4KCKaW+FRdzh2A0RpVuEDNqf2l8OZx4f/+HGdGAfuJOHBdmrO0OOUdJ8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773382390; c=relaxed/simple; bh=cCfNsCI87fg6TEnfgoRKAm3vjZfM30ZKoMGU1LRZRBo=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=dzZ4UCo6xphw74NnRt9sX18vTdGM0YkGXqXTsD8oV3W4qwzRS14weRsv8lIPAVWH0Eba/JMoRjdy92bG0teQbZQrtQFe1NfQMtcsm3JGERW65dgDkcilyqYBXCvY0xI3QZA1TqsXfEtZYB9T/LLcVGlV7BDeP2O6iOJ6ukYxJGo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--ackerleytng.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=ZBgbTAhe; arc=none smtp.client-ip=209.85.215.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--ackerleytng.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ZBgbTAhe" Received: by mail-pg1-f201.google.com with SMTP id 41be03b00d2f7-c73935acff2so942788a12.2 for ; Thu, 12 Mar 2026 23:13:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1773382388; x=1773987188; darn=vger.kernel.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=lTunW/QNrd+D2aaY5sITtIPS8ag2VRP0yYeRUeCHtMw=; b=ZBgbTAheyn74oo/DGKNYaeCqJCoOIr5Nan2IneK/Zzbx41TCYgZ0ZUE0a1MuBuXTDG C/c9iBt4REGSnWHx/tqr2OVSJvqUSn7kT+HcGha87IVSD2XjNZ6G+aNFuGVShaHCcfw8 nbGvBowREZ8LeyGQ7XUeyFCd6+c3i/+jx7+b+XsY0MMvK4sWQND7O1pTsv5VJtlq5qsw PodYvbcGRcBOQiaHSiJOE/tJ18umS0O0WDTKb4vizBK/XER0orYkpuh82YioY5cbNFEi umhZrXwqB0jPzybFgEIt+NXU/8lhMpm/nGAx7LvkEkoben5JQMvMuKSLJGRxFoGZ7Ljw fpgg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1773382388; x=1773987188; 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=lTunW/QNrd+D2aaY5sITtIPS8ag2VRP0yYeRUeCHtMw=; b=f6ulNKjhkHqIRxviGGsbenzgPLLKpQ/hyudAgQVlqYEI5hUZI76DEzNO8cc//SmidX gL9qIeOaL4RP57Lcv20yyngHeACJZFGr24Xv+xjfhci0HWBprQ23DrcIgpD38sz5Z9k+ 1xdmTUryOopaKCMnS9ymrEogk8WXGvAoj4XaEUKjiTAoV8F4z5mKwI3FW+HDqf59WtBS IsiLqee9OzqtqWn8z2RAu+FaV17RKMCiKBJ5J6yS6BdcCSbvAw2fqPc2xPuL1Ylgnwf5 XOjHwgoNtCqDauGqW1syOmkTKYcC8dg9YxmuJmKC6m6oQxtkNzGoM0Ab5ImM1sOaMap/ 7QkQ== X-Forwarded-Encrypted: i=1; AJvYcCV0tcUCRIgK6NK88Y4vJYpxe73RBO1Dq+RRR8wMyhWTwymsOAstynzCzuUrPvsNUQ0T5bXB1Ovk90qH5FqEpNQ=@vger.kernel.org X-Gm-Message-State: AOJu0Yz85375m1U/O5TZEuPmbuu3KX7yIM8Eag4salTsVG6XOhh3PlcG yKOvuWyH5nPAycwrXj90dOsBIRmzSeDGu3H4b2ymtDALloGW3z/lLNMoyANytfB0V7MQCU6ADB3 6YacKAPCKk3en2Nj/+NZgKzGqsA== X-Received: from pgww15.prod.google.com ([2002:a05:6a02:2c8f:b0:c65:d823:cdf2]) (user=ackerleytng job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:2d42:b0:398:7d4a:c2c5 with SMTP id adf61e73a8af0-398eca52535mr1641278637.20.1773382387685; Thu, 12 Mar 2026 23:13:07 -0700 (PDT) Date: Fri, 13 Mar 2026 06:12:51 +0000 In-Reply-To: <20260313-gmem-inplace-conversion-v3-0-5fc12a70ec89@google.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260313-gmem-inplace-conversion-v3-0-5fc12a70ec89@google.com> X-Developer-Key: i=ackerleytng@google.com; a=ed25519; pk=sAZDYXdm6Iz8FHitpHeFlCMXwabodTm7p8/3/8xUxuU= X-Developer-Signature: v=1; a=ed25519-sha256; t=1773382364; l=2855; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=nUG7MbP2VMtZ/RqI1k3lVv6HlTa0rLwtPHHfG9+apaQ=; b=gIIAcTAoq+uh6ZLKHTYgkGSDsVcXa8Oje6UJiWgcGy3Vt15Tyj1DsgsgEZxls9Z0bpWC4urhr c83+zR3qU4jB7TwLhF6aLoFZOf67MMkSywGzRdj1slybgAxZUnFmyqS X-Mailer: b4 0.14.3 Message-ID: <20260313-gmem-inplace-conversion-v3-12-5fc12a70ec89@google.com> Subject: [PATCH RFC v3 12/43] KVM: Let userspace disable per-VM mem attributes, enable per-gmem attributes From: Ackerley Tng 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, jroedel@suse.de, 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, 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 , 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, Ackerley Tng Content-Type: text/plain; charset="utf-8" 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 b8f5ce3a33e27..9744d3a7fd917 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -105,6 +105,7 @@ 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)); -- 2.53.0.851.ga537e3e6e9-goog