From nobody Wed Dec 17 16:11:42 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 422C834DB59; Wed, 17 Dec 2025 10:13:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765966400; cv=none; b=B06BORCMaZ1VttTJWqSlBgFLIUgkXHnE5rjsI0svGMwaINs2/XguoIPw1dPdAj3+HT78wA+/Az8+1fNeJ9rBHTJ59Yui6IxFBs5gTwK0E//WkAyFKRRwSoXRBCaYO9NoboAn3qJ5kexTWq3JTY5ixRFpRtbKsKKVb7WXDocjP1A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765966400; c=relaxed/simple; bh=Tpn7FiZgq89hMFDVxKpmX0RtN+RAQ0gHGCj9Ze8zXvg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jBuYErgRw+LdF6hHr4oZNfan3o4OJJQUkkQ8TTgyEVxzoGf1k9VAk5yekmZES9P+QhnjVxOqArY7XhWj2I48AMJC7qajvmZhpp/kfoZ6/mXi15twf7ZcdD32bQ64uVjEmzWniuiYDvDXBYEFezGSRMUXhZa2J++Z6Cvxkt6ZoGY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id AFD2D1691; Wed, 17 Dec 2025 02:13:11 -0800 (PST) Received: from e122027.arm.com (unknown [10.57.45.201]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 893B13F73B; Wed, 17 Dec 2025 02:13:14 -0800 (PST) From: Steven Price To: kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Steven Price , Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Suzuki K Poulose , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev, Ganapatrao Kulkarni , Gavin Shan , Shanker Donthineni , Alper Gun , "Aneesh Kumar K . V" , Emi Kisanuki , Vishal Annapurve Subject: [PATCH v12 19/46] KVM: arm64: Expose support for private memory Date: Wed, 17 Dec 2025 10:10:56 +0000 Message-ID: <20251217101125.91098-20-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251217101125.91098-1-steven.price@arm.com> References: <20251217101125.91098-1-steven.price@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Select KVM_GENERIC_MEMORY_ATTRIBUTES and provide the necessary support functions. Signed-off-by: Steven Price --- Changes since v10: * KVM_GENERIC_PRIVATE_MEM replacd with KVM_GENERIC_MEMORY_ATTRIBUTES. Changes since v9: * Drop the #ifdef CONFIG_KVM_PRIVATE_MEM guard from the definition of kvm_arch_has_private_mem() Changes since v2: * Switch kvm_arch_has_private_mem() to a macro to avoid overhead of a function call. * Guard definitions of kvm_arch_{pre,post}_set_memory_attributes() with #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES. * Early out in kvm_arch_post_set_memory_attributes() if the WARN_ON should trigger. --- arch/arm64/include/asm/kvm_host.h | 2 ++ arch/arm64/kvm/Kconfig | 1 + arch/arm64/kvm/mmu.c | 24 ++++++++++++++++++++++++ 3 files changed, 27 insertions(+) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm= _host.h index 5a24227088c1..7590d86c78a5 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1462,6 +1462,8 @@ struct kvm *kvm_arch_alloc_vm(void); =20 #define vcpu_is_protected(vcpu) kvm_vm_is_protected((vcpu)->kvm) =20 +#define kvm_arch_has_private_mem(kvm) ((kvm)->arch.is_realm) + int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature); bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu); =20 diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index 4f803fd1c99a..1cac6dfc0972 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -38,6 +38,7 @@ menuconfig KVM select SCHED_INFO select GUEST_PERF_EVENTS if PERF_EVENTS select KVM_GUEST_MEMFD + select KVM_GENERIC_MEMORY_ATTRIBUTES help Support hosting virtualized guest machines. =20 diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index cac3d7b73b3d..f2ac01c1de04 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -2503,6 +2503,30 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, return ret; } =20 +#ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES +bool kvm_arch_pre_set_memory_attributes(struct kvm *kvm, + struct kvm_gfn_range *range) +{ + WARN_ON_ONCE(!kvm_arch_has_private_mem(kvm)); + return false; +} + +bool kvm_arch_post_set_memory_attributes(struct kvm *kvm, + struct kvm_gfn_range *range) +{ + if (WARN_ON_ONCE(!kvm_arch_has_private_mem(kvm))) + return false; + + if (range->arg.attributes & KVM_MEMORY_ATTRIBUTE_PRIVATE) + range->attr_filter =3D KVM_FILTER_SHARED; + else + range->attr_filter =3D KVM_FILTER_PRIVATE; + kvm_unmap_gfn_range(kvm, range); + + return false; +} +#endif + void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot) { } --=20 2.43.0