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bh=YkFqhRwEQZVyHiDJUj6H4E4tU4Wvsdzaj7skS/qkZuE=; b=fYqOIs0iI3/nAEboIQ/PrkKD3DqiKgh0ZKOH0/alwG+ByCa4bQDdDE7B7eewnHx+Vkr5yyN3L qYWooCrUe9JDhY0cerupGdZo3deYAs2/zlmrWXsG3XBYe8lS1/Lli9y X-Mailer: b4 0.14.3 Message-ID: <20260326-gmem-inplace-conversion-v4-17-e202fe950ffd@google.com> Subject: [PATCH RFC v4 17/44] 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 , Andrew Morton , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , 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, Ackerley Tng Content-Type: text/plain; charset="utf-8" X-Rspamd-Queue-Id: B1D741C000A X-Stat-Signature: win8do184jopjyuo3knxmuaduisjajra X-Rspam-User: X-Rspamd-Server: rspam02 X-HE-Tag: 1774563900-985233 X-HE-Meta: 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 CfjxE85V 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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 6607127eaaeed..05e203f5292be 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)); -- 2.53.0.1018.g2bb0e51243-goog