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 F304FC55182 for ; Mon, 3 Aug 2026 13:47:57 +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=iZYPOtrKEegzwigkJVAGbq48icoKREsK4VU6SCJoRN8=; b=YUwuvoDERo5oimoSnXplnvWMdW MeNUhu3iJdwSKe3pnt7jSal3U8RiTmOqALyAl7Vy7ftEbRyi4SlKxeFcZadJmazTg8N+7ApZG9yl8 IawhKC06HJRA8blZHRPwYhfA+kuncXcA0dpOXC2TY8iMetfYwvnzpneAFuI7ZWluwJThsOpBSx9pf nXrqDgxIXd7qr5k7KNzMiD6kQ20qB6QHYHedk4r2oRZ5p3GJjitiG6QTepzSYP1mGZqNPVPEWsReq xd3waUWbYnR97N1goTSu8WxuYkEkijwHXBt2JazhtoZQQcYxTxBHdzBtwycRQ+0C+t3rPARzQHEv4 RLroe2dA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wqt1D-0000000HEyk-1dzM; Mon, 03 Aug 2026 13:47:51 +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 1wqt1A-0000000HEwO-3a4U for linux-arm-kernel@lists.infradead.org; Mon, 03 Aug 2026 13:47:50 +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 656931476; Mon, 3 Aug 2026 06:47:42 -0700 (PDT) Received: from e122027.cambridge.arm.com (e122027.cambridge.arm.com [10.1.25.28]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B81D03F66F; Mon, 3 Aug 2026 06:47:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1785764866; bh=hU5/Y8gLAYSgHVaaIBAsTIEwnwJD0RpetBq00JLKOGU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EqPEZkcECjXMW/VhDiaE+juIi+dG8W9nNkF9DspL9f2NlLZ43EJqeEQim6ialXL4w FlZ1572dutPCpiphYSWqn+cTBE5ZA8q66IxT8CVQCvY+uOj/OyA6HspeF9UpttJ+CB RwogHDCHvHnoka54u8OW8QPpszwgy5yfxCARZVd4= 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 Pieralisi Subject: [PATCH v16 44/45] KVM: arm64: CCA: Require ICH_HCR_EL2.TDIR for realms Date: Mon, 3 Aug 2026 14:44:00 +0100 Message-ID: <20260803134403.80630-45-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260803134403.80630-1-steven.price@arm.com> References: <20260803134403.80630-1-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-20260803_064749_021807_3E368F5E X-CRM114-Status: GOOD ( 12.97 ) 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 KVM advertises realm support when the RMM is available, and allows userspace to create a VM with KVM_VM_TYPE_ARM_REALM on that basis. On CPUs that lack ICH_HCR_EL2.TDIR, KVM uses ICH_HCR_EL2.TC for normal guests so that ICC_DIR_EL1 is still trapped via the common GICv3 CPU interface trap. Realms cannot rely on the normal hyp-side trap handling for that fallback, so advertising RMI support on such systems lets userspace create a realm that cannot safely run. Require the finalized ARM64_HAS_ICH_HCR_EL2_TDIR capability when reporting KVM_CAP_ARM_RMI and when accepting KVM_VM_TYPE_ARM_REALM. This leaves normal VM creation unchanged on systems that need the TC workaround. Signed-off-by: Steven Price --- New patch for v16 --- arch/arm64/kvm/arm.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index fd4e13ff17cf..7edc572dd8ab 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -125,6 +125,12 @@ static bool vgic_present, kvm_arm_initialised; static DEFINE_PER_CPU(unsigned char, kvm_hyp_initialized); +static bool kvm_arm_rmi_supported(void) +{ + return static_key_enabled(&kvm_rmi_is_available) && + cpus_have_final_cap(ARM64_HAS_ICH_HCR_EL2_TDIR); +} + bool is_kvm_arm_initialised(void) { return kvm_arm_initialised; @@ -256,7 +262,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) return -EINVAL; if (type & KVM_VM_TYPE_ARM_REALM) { - if (!static_branch_unlikely(&kvm_rmi_is_available)) + if (!kvm_arm_rmi_supported()) return -EINVAL; kvm_set_realm_state(kvm, REALM_STATE_NONE); kvm->arch.is_realm = true; @@ -537,7 +543,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = kvm_supports_cacheable_pfnmap(); break; case KVM_CAP_ARM_RMI: - r = static_key_enabled(&kvm_rmi_is_available); + r = kvm_arm_rmi_supported(); break; default: -- 2.43.0