From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1D5D3CD4F21 for ; Wed, 13 May 2026 13:20:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=9FlFwWHyfeLVSzy7dxeX6YuLnhCqsxZ+9PmC5R6EYAE=; b=He3pQml19FAMcKFKFzK9A/FIMO +AP/U31tPULrFxCsXlhbMWiNpcntEycwWerIqICaJyXBc4DQuspoXslomjNx7AGHhYklUc9sGhGdw CKqKOZwBcuGHPbT28l2LxfRje/JuasrpqTYi8yVF2IJTLrhsuE8B/66G5QrFW7516H+28m/uNeKUn sjSVC4+6bORiQXbH+PDYbc51G9mZB2/x3k1do+MPTkMc5oWZeN/oicKNeXbxr9sSNXNn7TrsRG5Jx m7lFnfhrOwDkQltEl8/iBQrWaiDKLsrjedVQcqsBoColX/6rc5Hp7UwLei7anc5qMxXbIGmdEXSmv 6O5ymhYA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wN9W4-00000002gs1-1c4f; Wed, 13 May 2026 13:20:48 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wN9Vu-00000002gfG-1I6L for linux-arm-kernel@lists.infradead.org; Wed, 13 May 2026 13:20:43 +0000 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 728F330B1; Wed, 13 May 2026 06:20:31 -0700 (PDT) Received: from e122027.arm.com (unknown [10.57.68.187]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1B5773F836; Wed, 13 May 2026 06:20:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1778678436; bh=YndVBENKT7za7Eh2CgyvzwtNsJtX3XG29UQvOY5vpGI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LxXlHadbmDg6/uoY8VbuxewTVGFI8q1uoTPhTJ2hyFqYxekVi5Vf3AJge5+vIDD0K TVhxdF5mw0hjyHqK5GaPsWbJ++vc3s1ofLEGE1DJLOcQZAZMW+f4VMJMdalAGzs++6 XiVuOsAC/5IDR9JqRFjvJE9IZPYjhXR+UB9CB3+4= 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 , WeiLin.Chang@arm.com, Lorenzo.Pieralisi2@arm.com Subject: [PATCH v14 25/44] KVM: arm64: Expose support for private memory Date: Wed, 13 May 2026 14:17:33 +0100 Message-ID: <20260513131757.116630-26-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260513131757.116630-1-steven.price@arm.com> References: <20260513131757.116630-1-steven.price@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260513_062038_551756_E66B0F85 X-CRM114-Status: GOOD ( 14.08 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Select KVM_GENERIC_MEMORY_ATTRIBUTES and provide the necessary support functions. Signed-off-by: Steven Price --- Changes since v13: * Also update documentation to show that KVM_CAP_MEMORY_ATTRIBUTES is used on arm64. Changes since v12: * Only define kvm_arch_has_private_mem() when CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES is set to avoid build issues when KVM is disabled. 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. --- Documentation/virt/kvm/api.rst | 2 +- arch/arm64/include/asm/kvm_host.h | 4 ++++ arch/arm64/kvm/Kconfig | 1 + arch/arm64/kvm/mmu.c | 24 ++++++++++++++++++++++++ 4 files changed, 30 insertions(+), 1 deletion(-) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 31a5919d8d5f..a47c60490475 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6379,7 +6379,7 @@ Returns -EINVAL if called on a protected VM. ------------------------------- :Capability: KVM_CAP_MEMORY_ATTRIBUTES -:Architectures: x86 +:Architectures: x86, arm64 :Type: vm ioctl :Parameters: struct kvm_memory_attributes (in) :Returns: 0 on success, <0 on error diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 39b5de03d0fe..11e7b629c950 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1531,6 +1531,10 @@ struct kvm *kvm_arch_alloc_vm(void); #define vcpu_is_protected(vcpu) kvm_vm_is_protected((vcpu)->kvm) +#ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES +#define kvm_arch_has_private_mem(kvm) ((kvm)->arch.is_realm) +#endif + int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature); bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu); diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index 449154f9a485..4e16719fda22 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -37,6 +37,7 @@ 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. diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 10ca9dbe40a0..ac2a0f0106b0 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -2684,6 +2684,30 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, return ret; } +#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 = KVM_FILTER_SHARED; + else + range->attr_filter = 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) { } -- 2.43.0