From nobody Sun Feb 8 22:57:54 2026 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 56AE7FA3744 for ; Sun, 30 Oct 2022 06:25:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229947AbiJ3GZS (ORCPT ); Sun, 30 Oct 2022 02:25:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46946 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229833AbiJ3GYF (ORCPT ); Sun, 30 Oct 2022 02:24:05 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADDD0DE; Sat, 29 Oct 2022 23:24:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1667111044; x=1698647044; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=1K4yf7A4XzVtLVElMggRuvYNfU2q/PlhFY/Ez4kSMlc=; b=ggxUr75BvmJfou7PeGA5nR8RHFENjYai2Lo8fCCdG8Jg1Py+3IKzcR2o 9QtatENnwj2cT3xGHmquVP1FFR+jZDpYZuTZaRC35RXkVNKZy1Rqjk6tk AsQVZxIGa37mXadDL3MZAd9sb1v41cTolI38PzsRcVBl40EGZSQtVp0yT HD+5uI0p40eSp0+1WauBUMFwim3qsXIFir/O0Shh0yAwpIJK7oVkkmUnZ 5oue1Zlw8UtWwvfaJqtjllOXY18JPaoL2DMRNv+rv/8vFD8CGAyhxqZKA Japto/os3+BUG/xTiQd7s9inTveEr0ur/4+ZTF++O2rPNytBZGXvT+bIK w==; X-IronPort-AV: E=McAfee;i="6500,9779,10515"; a="395037132" X-IronPort-AV: E=Sophos;i="5.95,225,1661842800"; d="scan'208";a="395037132" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Oct 2022 23:24:00 -0700 X-IronPort-AV: E=McAfee;i="6500,9779,10515"; a="878392891" X-IronPort-AV: E=Sophos;i="5.95,225,1661842800"; d="scan'208";a="878392891" Received: from ls.sc.intel.com (HELO localhost) ([143.183.96.54]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Oct 2022 23:23:59 -0700 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 v10 020/108] KVM: Support KVM_CAP_MAX_VCPUS for KVM_ENABLE_CAP Date: Sat, 29 Oct 2022 23:22:21 -0700 Message-Id: <07daa8dbe1e3d6fec8db47a3ff3422a9bc460548.1667110240.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 | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index b9c270f97c88..3b05a3396f89 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4967,6 +4967,27 @@ static int kvm_vm_ioctl_enable_cap_generic(struct kv= m *kvm, case KVM_CAP_DIRTY_LOG_RING: case KVM_CAP_DIRTY_LOG_RING_ACQ_REL: return kvm_vm_ioctl_enable_dirty_log_ring(kvm, cap->args[0]); + case KVM_CAP_MAX_VCPUS: { + int r; + + 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: return kvm_vm_ioctl_enable_cap(kvm, cap); } --=20 2.25.1