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 414E7C55182 for ; Mon, 3 Aug 2026 13:47:41 +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=6ESOnNs12jMrOdMe0t88MLcMW34OSjkRJLG6mHpvS94=; b=SKOSQhCAGQdMYHHND2DTuNjkud 1N27lLl1POBtgNd5+7B51sPhftiv+pS2hL3F3lzOE42sw2aplt11Qffd8kEsdATCo0aJ6kwpgMjhQ 8hCRPmiUtVt6TKLmyo6QeFBAkSRkg29QG9KYKRbLXBdKHP3c3EPZnfvvLqbQqNsY+0eyWbfcAXL4O dyyGUGCcQthQPIZlkWlxPJkiiZSuW6/SP3hPuHDUx6faPt6OvoDO9kFD+W8Ct6E0Fn8YuYt9yKRYN yvyevr5SeQN8C2QyGbHvqfqOLpTZ2fkW8D2I4y9mnxmX9erQu0gdqGhY44IFmO5mtNo8L6VNlAXvs JFBnqn6A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wqt0w-0000000HEk7-3ptU; Mon, 03 Aug 2026 13:47:34 +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 1wqt0u-0000000HEhw-1x8o for linux-arm-kernel@lists.infradead.org; Mon, 03 Aug 2026 13:47:34 +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 C0566165C; Mon, 3 Aug 2026 06:47:27 -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 CFF663F66F; Mon, 3 Aug 2026 06:47:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1785764851; bh=QbXqYIX01Dxf57p9QrsPRpSm8WGko41S0UwAnL78VD8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qqOZ1lUn+6MK9Ys8IBGQjQ++t3wZu7QB6Sf4KJ9fhMBHZThChHEOEqymmPSBX5py9 JVpMxkFSfLpVEdVhFJNqrYyMqiW6pjyKBlOtptob2bNVjmVPqAOteFIoMi6Ayxnu7d 201D44sgbfzPJxgfcomiabDQuPlPralDcF/xBkZg= From: Steven Price To: kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Jean-Philippe Brucker , 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 , Steven Price Subject: [PATCH v16 41/45] KVM: arm64: CCA: Configure max SVE vector length for a Realm Date: Mon, 3 Aug 2026 14:43:57 +0100 Message-ID: <20260803134403.80630-42-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_064732_609767_94448A6A X-CRM114-Status: GOOD ( 18.19 ) 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 From: Jean-Philippe Brucker Obtain the max vector length configured by userspace on the vCPUs, and write it into the Realm parameters. By default the vCPU is configured with the max vector length reported by RMM, and userspace can reduce it with a write to KVM_REG_ARM64_SVE_VLS. Signed-off-by: Jean-Philippe Brucker Signed-off-by: Steven Price --- Changes since v6: * Rename max_vl/realm_max_vl to vl/last_vl - there is nothing "maximum" about them, we're just checking that all realms have the same vector length --- arch/arm64/kvm/guest.c | 3 ++- arch/arm64/kvm/rmi.c | 37 +++++++++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index f48fc0d5a249..452cf5d3152e 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -361,7 +361,7 @@ static int set_sve_vls(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) if (!vcpu_has_sve(vcpu)) return -ENOENT; - if (kvm_arm_vcpu_sve_finalized(vcpu)) + if (kvm_arm_vcpu_sve_finalized(vcpu) || kvm_realm_is_created(vcpu->kvm)) return -EPERM; /* too late! */ if (WARN_ON(vcpu->arch.sve_state)) @@ -754,6 +754,7 @@ static bool validate_realm_set_reg(struct kvm_vcpu *vcpu, } else { switch (reg->id) { case KVM_REG_ARM_ID_AA64DFR0_EL1: + case KVM_REG_ARM64_SVE_VLS: return true; } } diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c index cf043db05720..0f66a0e970cd 100644 --- a/arch/arm64/kvm/rmi.c +++ b/arch/arm64/kvm/rmi.c @@ -504,6 +504,39 @@ static void realm_unmap_shared_range(struct kvm *kvm, start, end); } +static int realm_init_sve_param(struct kvm *kvm, struct realm_params *params) +{ + unsigned long i; + struct kvm_vcpu *vcpu; + int vl, last_vl = -1; + + if (!kvm_has_sve(kvm)) + return 0; + + /* + * Get the preferred SVE configuration, set by userspace with the + * KVM_ARM_VCPU_SVE feature and KVM_REG_ARM64_SVE_VLS pseudo-register. + */ + kvm_for_each_vcpu(i, vcpu, kvm) { + if (!kvm_arm_vcpu_sve_finalized(vcpu)) + return -EINVAL; + + vl = vcpu->arch.sve_max_vl; + + /* We need all vCPUs to have the same SVE config */ + if (last_vl >= 0 && last_vl != vl) + return -EINVAL; + + last_vl = vl; + } + + if (last_vl > 0) { + params->sve_vl = sve_vq_from_vl(last_vl) - 1; + params->flags0 |= RMI_REALM_PARAM_FLAG_SVE; + } + return 0; +} + static int realm_create_rd(struct kvm *kvm) { struct realm *realm = &kvm->arch.realm; @@ -556,6 +589,10 @@ static int realm_create_rd(struct kvm *kvm) if (kvm_lpa2_is_enabled()) params->flags0 |= RMI_REALM_PARAM_FLAG_LPA2; + r = realm_init_sve_param(kvm, params); + if (r) + goto out_undelegate_tables; + params_phys = virt_to_phys(params); rmi_ret = rmi_realm_create(rd_phys, params_phys, realm->sro); -- 2.43.0