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AHgh+RomqjgUy7fOjUyTJP+/YFGBwM7e8tXSZSI2z4qGAyvpY/NTv87gLmpeomV1S/xL/FIN/vqJaOYwg63C@lists.linux.dev X-Gm-Message-State: AFuF++kJq8ijN56F9iAtb1GacLdIMTbnwZxNkRlyH30Q3c8Ll+7LpWSa PYRF47qVvA68z+qsw1FKyoSZDEqcHjleu+uGaehC3UrzqdCJlq+bPynaA06rgKul6Wg5DKnsNHa S/is/UHJTRxLLDSjAwHfFm3CbvA== X-Received: from plbmz11.prod.google.com ([2002:a17:903:350b:b0:2ca:cbc9:76fd]) (user=ackerleytng job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:38c8:b0:2d5:ccb7:12c3 with SMTP id d9443c01a7336-2d7079579a8mr85171415ad.2.1787735901060; Wed, 26 Aug 2026 02:18:21 -0700 (PDT) Date: Wed, 26 Aug 2026 09:18:06 +0000 In-Reply-To: <20260826-gmem-inplace-conversion-v11-0-0a15d8a799aa@google.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260826-gmem-inplace-conversion-v11-0-0a15d8a799aa@google.com> X-Developer-Key: i=ackerleytng@google.com; a=ed25519; pk=sAZDYXdm6Iz8FHitpHeFlCMXwabodTm7p8/3/8xUxuU= X-Developer-Signature: v=1; a=ed25519-sha256; t=1787735885; l=3261; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=MYp0jcv/vyqcAp2jfObXcS1n8zbY2OhrXS0jgL07qmI=; b=OjjqRhEDO3WNi+cijL7f8lpbM+OYCuVBl/W4q/2CiXbz6fOaq/lU1MP9wqHNLxp82huANiFAg XO5HfFH8jJwBqR2M0mKoQUKWsQqP9fUpPRG2nMdyg4DpIjwzDgaVUTk X-Mailer: b4 0.16.0 Message-ID: <20260826-gmem-inplace-conversion-v11-8-0a15d8a799aa@google.com> Subject: [PATCH v11 08/46] KVM: Provide generic interface for checking memory private/shared status 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, 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, 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 , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Youngjun Park , Qi Zheng , Shakeel Butt , Kiryl Shutsemau , Baoquan He , Jason Gunthorpe , John Hubbard , Peter Xu , tarunsahu@google.com, Fuad Tabba , 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 , Xiaoyao Li Content-Type: text/plain; charset="utf-8" From: Sean Christopherson Introduce a generic kvm_is_private_gfn() interface using a static call to determine if a GFN is private. This allows the implementation for checking a GFN's private/shared status to be set at runtime. In preparation for choosing implementations between a guest_memfd lookup and the existing VM attribute lookup, rename the existing VM-attribute-based check to kvm_vm_is_private_gfn() to emphasize that it looks up VM attributes. Signed-off-by: Sean Christopherson Reviewed-by: Xiaoyao Li Reviewed-by: Fuad Tabba Tested-by: Shivank Garg Reviewed-by: Binbin Wu Signed-off-by: Ackerley Tng --- include/linux/kvm_host.h | 14 ++++++++++++-- virt/kvm/kvm_main.c | 15 +++++++++++++++ 2 files changed, 27 insertions(+), 2 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 9b97266f61ec8..3579feb631775 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -2573,16 +2573,26 @@ bool kvm_arch_pre_set_vm_memory_attributes(struct kvm *kvm, bool kvm_arch_post_set_vm_memory_attributes(struct kvm *kvm, struct kvm_gfn_range *range); -static inline bool kvm_is_private_gfn(struct kvm *kvm, gfn_t gfn) +static inline bool kvm_vm_is_private_gfn(struct kvm *kvm, gfn_t gfn) { return kvm_get_vm_memory_attributes(kvm, gfn) & KVM_MEMORY_ATTRIBUTE_PRIVATE; } +#endif /* CONFIG_KVM_VM_MEMORY_ATTRIBUTES */ + +#ifdef kvm_arch_has_private_mem +typedef bool (kvm_is_private_gfn_t)(struct kvm *kvm, gfn_t gfn); +DECLARE_STATIC_CALL(__kvm_is_private_gfn, kvm_is_private_gfn_t); + +static inline bool kvm_is_private_gfn(struct kvm *kvm, gfn_t gfn) +{ + return static_call(__kvm_is_private_gfn)(kvm, gfn); +} #else static inline bool kvm_is_private_gfn(struct kvm *kvm, gfn_t gfn) { return false; } -#endif /* CONFIG_KVM_VM_MEMORY_ATTRIBUTES */ +#endif /* kvm_arch_has_private_mem */ #ifdef CONFIG_KVM_GUEST_MEMFD int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 91d5af7d60d0f..78278730b2ae4 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2628,6 +2628,20 @@ static int kvm_vm_ioctl_set_mem_attributes(struct kvm *kvm, } #endif /* CONFIG_KVM_VM_MEMORY_ATTRIBUTES */ +#ifdef kvm_arch_has_private_mem +DEFINE_STATIC_CALL_RET0(__kvm_is_private_gfn, kvm_is_private_gfn_t); +EXPORT_STATIC_CALL_GPL(__kvm_is_private_gfn); + +static void kvm_init_memory_attributes(void) +{ +#ifdef CONFIG_KVM_VM_MEMORY_ATTRIBUTES + static_call_update(__kvm_is_private_gfn, kvm_vm_is_private_gfn); +#endif +} +#else +static void kvm_init_memory_attributes(void) { } +#endif + struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn) { return __gfn_to_memslot(kvm_memslots(kvm), gfn); @@ -6541,6 +6555,7 @@ int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module) kvm_preempt_ops.sched_in = kvm_sched_in; kvm_preempt_ops.sched_out = kvm_sched_out; + kvm_init_memory_attributes(); kvm_init_debug(); r = kvm_vfio_ops_init(); -- 2.55.0.887.g758fc8c411-goog