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 41640CD4F21 for ; Wed, 13 May 2026 13:22:19 +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=E1mA1h4g1leG8sFXhNKOSY7SsWfsjPLu9NeQwfT5kkw=; b=yolOCKlOx2Mzt0QiXMOqjmBJyb p6eEWkVKCLdZQpRatFD0+ydndiJA3YYLLE9Z1ro73aP7A4EbQQqOAS63rhzGu3bHf6/4p84U/sIfU gs7iZdD4ZsqgQsQNq8nRNvykBMVGi/NufhhHjptsRnYl8ZuqMWEszqa2kK+WaCiUTktFub6uwjspk GRsY7YBhdAtv0SwHJ/lG0BrVZkbfRiaPDXNcL0mvTC5cKNJtGUBCg3MAMdEOkcuuY8FLEco0/Q+2Z M6uv18WrN+xRDA6lAKikqTq94kUSqag7r5DrGrfFiDxj9aeVm15Xl0h6UwxhbVxMtWVD35yqb8p4c IBM/s3UQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wN9XR-00000002iUD-0p1u; Wed, 13 May 2026 13:22:13 +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 1wN9XK-00000002iMj-3Jpx for linux-arm-kernel@lists.infradead.org; Wed, 13 May 2026 13:22:08 +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 2CCD81477; Wed, 13 May 2026 06:22:00 -0700 (PDT) Received: from e122027.arm.com (unknown [10.57.68.187]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DFB323F836; Wed, 13 May 2026 06:21:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1778678525; bh=yQ39/U7Citn4HDvdnFItsEuCdUPNSy3tFdNOjQr6S9E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ICFSbZfxr25tDCPu5zVvTISe0LhNpLh9FhravP1eKYulUXjowFvvPIhhD+w3lRRrM tNh2/3L4yoTmv3R56JrTFHkJg749HmKIXaMwqJGiAJA5ir979q76sgRbyBYdXDZXgM vG2siJmuUXqKcMx7uMuwrvoTakxH8EqtcHwNJASo= 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.Pieralisi2@arm.com, Steven Price Subject: [PATCH v14 41/44] arm64: RMI: Configure max SVE vector length for a Realm Date: Wed, 13 May 2026 14:17:49 +0100 Message-ID: <20260513131757.116630-42-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_062206_940250_327A6649 X-CRM114-Status: GOOD ( 17.80 ) 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 a92bd07ef53a..5f451ee18649 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 35ad65efa5db..732cecb11355 100644 --- a/arch/arm64/kvm/rmi.c +++ b/arch/arm64/kvm/rmi.c @@ -468,6 +468,39 @@ 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->flags |= RMI_REALM_PARAM_FLAG_SVE; + } + return 0; +} + static int realm_create_rd(struct kvm *kvm) { struct realm *realm = &kvm->arch.realm; @@ -513,6 +546,10 @@ static int realm_create_rd(struct kvm *kvm) if (kvm_lpa2_is_enabled()) params->flags |= RMI_REALM_PARAM_FLAG_LPA2; + r = realm_init_sve_param(kvm, params); + if (r) + goto out_undelegate_tables; + params_phys = virt_to_phys(params); if (rmi_realm_create(rd_phys, params_phys)) { -- 2.43.0