From patchwork Wed Jun 21 06:10:49 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Mackerras X-Patchwork-Id: 9800827 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4F65A60234 for ; Wed, 21 Jun 2017 06:10:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3AD9228528 for ; Wed, 21 Jun 2017 06:10:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2F58A2852C; Wed, 21 Jun 2017 06:10:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AB34028528 for ; Wed, 21 Jun 2017 06:10:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751774AbdFUGKz (ORCPT ); Wed, 21 Jun 2017 02:10:55 -0400 Received: from ozlabs.org ([103.22.144.67]:40243 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751754AbdFUGKy (ORCPT ); Wed, 21 Jun 2017 02:10:54 -0400 Received: by ozlabs.org (Postfix, from userid 1003) id 3wsvTm6lP6z9s78; Wed, 21 Jun 2017 16:10:52 +1000 (AEST) Date: Wed, 21 Jun 2017 16:10:49 +1000 From: Paul Mackerras To: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org Cc: Sam Bobroff Subject: [PATCH] KVM: PPC: Book3S HV: Add capability to report possible virtual SMT modes Message-ID: <20170621061049.GB3644@fergus.ozlabs.ibm.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Now that userspace can set the virtual SMT mode by enabling the KVM_CAP_PPC_SMT capability, it is useful for userspace to be able to query the set of possible virtual SMT modes. This provides a new capability, KVM_CAP_PPC_SMT_POSSIBLE, to provide this information. The return value is a bitmap of possible modes, with bit N set if virtual SMT mode 2^N is available. That is, 1 indicates SMT1 is available, 2 indicates that SMT2 is available, 3 indicates that both SMT1 and SMT2 are available, and so on. Signed-off-by: Paul Mackerras --- This patch is intended to be applied on top of my patches "KVM: PPC: Book3S HV: Allow userspace to set the desired SMT mode" and "KVM: PPC: Book3S HV: Virtualize doorbell facility on POWER9". Documentation/virtual/kvm/api.txt | 11 +++++++++++ arch/powerpc/kvm/powerpc.c | 10 ++++++++++ include/uapi/linux/kvm.h | 1 + 3 files changed, 22 insertions(+) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 1531a3c..63875db 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -4010,6 +4010,8 @@ be 0. A successful call to enable this capability will result in vsmt_mode being returned when the KVM_CAP_PPC_SMT capability is subsequently queried for the VM. This capability is only supported by HV KVM, and can only be set before any VCPUs have been created. +The KVM_CAP_PPC_SMT_POSSIBLE capability indicates which virtual SMT +modes are available. 7.12 KVM_CAP_PPC_FWNMI @@ -4183,3 +4185,12 @@ Currently the following bits are defined for the device_irq_level bitmap: Future versions of kvm may implement additional events. These will get indicated by returning a higher number from KVM_CHECK_EXTENSION and will be listed above. + +8.10 KVM_CAP_PPC_SMT_POSSIBLE + +Architectures: ppc + +Querying this capability returns a bitmap indicating the possible +virtual SMT modes that can be set using KVM_CAP_PPC_SMT. If bit N +(counting from the right) is set, then a virtual SMT mode of 2^N is +available. diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index ccaa7a4..b14736f 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -566,6 +566,16 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = threads_per_subcore; } break; + case KVM_CAP_PPC_SMT_POSSIBLE: + r = 1; + if (hv_enabled) { + if (!cpu_has_feature(CPU_FTR_ARCH_300)) + r = ((threads_per_subcore << 1) - 1); + else + /* P9 can emulate dbells, so allow any mode */ + r = 8 | 4 | 2 | 1; + } + break; case KVM_CAP_PPC_RMA: r = 0; break; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 89bc145..36ea74a 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -896,6 +896,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_X86_GUEST_MWAIT 143 #define KVM_CAP_ARM_USER_IRQ 144 #define KVM_CAP_PPC_FWNMI 145 +#define KVM_CAP_PPC_SMT_POSSIBLE 146 #ifdef KVM_CAP_IRQ_ROUTING