From nobody Mon Sep 15 11:31:30 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BFAFCC678D8 for ; Thu, 12 Jan 2023 16:44:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240889AbjALQnn (ORCPT ); Thu, 12 Jan 2023 11:43:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41992 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239713AbjALQhg (ORCPT ); Thu, 12 Jan 2023 11:37:36 -0500 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0008C15FC3; Thu, 12 Jan 2023 08:33:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1673541234; x=1705077234; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=dqYEULkH/OZWopqWd2YjxrOh4qpDuxImjqn9TYIIMZY=; b=cQf8xKSdZBBDBQqZiDYXjiku8AIGjW/wqnZicg44Gx5V9D38zXuJFnCy 03cAjI6c9cnV/gUB1mzs1nWEIvw1XoOe8DPXP8iKN+LEJwWG/Ws8fDhfA z43u0pxrTmnunYJB5WfqKU+l2DtLu9wFxQz8SqZh2YWiYJMFLY+jNzNg+ aPXcINNjefjfpLb7pPPz1Nbg3DN6cQqqPMTo0UI4jjpaT5iqMBXn+TiN4 ItigkvQkqsa8O2L4w4i27sjAZouQzy9kKGec8kQQatPmYXxYYzqmwo+DX Um6VAOTGgJRmh1hBj/yQFoQycotMuNW+VSa6pigUS/QSGYHTGWUpIusS+ Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10588"; a="323811724" X-IronPort-AV: E=Sophos;i="5.97,211,1669104000"; d="scan'208";a="323811724" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2023 08:33:22 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10588"; a="721151680" X-IronPort-AV: E=Sophos;i="5.97,211,1669104000"; d="scan'208";a="721151680" Received: from ls.sc.intel.com (HELO localhost) ([143.183.96.54]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2023 08:33:22 -0800 From: isaku.yamahata@intel.com To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: isaku.yamahata@intel.com, isaku.yamahata@gmail.com, Paolo Bonzini , erdemaktas@google.com, Sean Christopherson , Sagi Shahar , David Matlack Subject: [PATCH v11 017/113] KVM: Support KVM_CAP_MAX_VCPUS for KVM_ENABLE_CAP Date: Thu, 12 Jan 2023 08:31:25 -0800 Message-Id: <01e061779b88ce4d32bbe483ed2bd3224cd8e330.1673539699.git.isaku.yamahata@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Isaku Yamahata TDX attestation includes the maximum number of vcpu that the guest can accommodate. For that, the maximum number of vcpu needs to be specified instead of constant, KVM_MAX_VCPUS. Make KVM_ENABLE_CAP support KVM_CAP_MAX_VCPUS. Suggested-by: Sagi Shahar Signed-off-by: Isaku Yamahata --- virt/kvm/kvm_main.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index a235b628b32f..1cfa7da92ad0 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4945,7 +4945,27 @@ static int kvm_vm_ioctl_enable_cap_generic(struct kv= m *kvm, } =20 mutex_unlock(&kvm->slots_lock); + return r; + } + case KVM_CAP_MAX_VCPUS: { + int r; =20 + if (cap->flags || cap->args[0] =3D=3D 0) + return -EINVAL; + if (cap->args[0] > kvm_vm_ioctl_check_extension(kvm, KVM_CAP_MAX_VCPUS)) + return -E2BIG; + + mutex_lock(&kvm->lock); + /* Only decreasing is allowed. */ + if (cap->args[0] > kvm->max_vcpus) + r =3D -E2BIG; + else if (kvm->created_vcpus) + r =3D -EBUSY; + else { + kvm->max_vcpus =3D cap->args[0]; + r =3D 0; + } + mutex_unlock(&kvm->lock); return r; } default: --=20 2.25.1