From patchwork Tue Nov 16 16:34:38 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12622933 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE6B9C433EF for ; Tue, 16 Nov 2021 16:36:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A83AB6108D for ; Tue, 16 Nov 2021 16:36:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235148AbhKPQjG (ORCPT ); Tue, 16 Nov 2021 11:39:06 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:32969 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234128AbhKPQiH (ORCPT ); Tue, 16 Nov 2021 11:38:07 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1637080509; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xVDknFf2nCeVQlDtcEI9s9kI+cRfWuofuSSpiZvEcD4=; b=R7T/G9XBny/F46t389UCxwKE/8Vu/puuqB91GgDZuFUsmwOpc0L0tfEZo1y9LRWV8BTUVk VNekTvxEtpq8kF69Sxi1GUFAJhgR++cy1i+fWXH3vcluymeOb4RhEh6NDKxGP7LfvYi5H6 On4LqYYnH7aWXq2DrVbh8hEKOKmaBgQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-255-hkd7BFgZMVaKSNGfz14umw-1; Tue, 16 Nov 2021 11:35:04 -0500 X-MC-Unique: hkd7BFgZMVaKSNGfz14umw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D27BA87D543; Tue, 16 Nov 2021 16:35:01 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.192.236]) by smtp.corp.redhat.com (Postfix) with ESMTP id 204FD60C0F; Tue, 16 Nov 2021 16:34:52 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , Eduardo Habkost , Marc Zyngier , Andrew Jones , Huacai Chen , Aleksandar Markovic , Anup Patel , Paul Mackerras , Michael Ellerman , Christian Borntraeger , Janosch Frank , kvm-ppc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/6] KVM: arm64: Cap KVM_CAP_NR_VCPUS by kvm_arm_default_max_vcpus() Date: Tue, 16 Nov 2021 17:34:38 +0100 Message-Id: <20211116163443.88707-2-vkuznets@redhat.com> In-Reply-To: <20211116163443.88707-1-vkuznets@redhat.com> References: <20211116163443.88707-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org Generally, it doesn't make sense to return the recommended maximum number of vCPUs which exceeds the maximum possible number of vCPUs. Note: ARM64 is special as the value returned by KVM_CAP_MAX_VCPUS differs depending on whether it is a system-wide ioctl or a per-VM one. Previously, KVM_CAP_NR_VCPUS didn't have this difference and it seems preferable to keep the status quo. Cap KVM_CAP_NR_VCPUS by kvm_arm_default_max_vcpus() which is what gets returned by system-wide KVM_CAP_MAX_VCPUS. Signed-off-by: Vitaly Kuznetsov Acked-by: Marc Zyngier --- arch/arm64/kvm/arm.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 7838e9fb693e..0690c76def5d 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -223,7 +223,14 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = 1; break; case KVM_CAP_NR_VCPUS: - r = num_online_cpus(); + /* + * ARM64 treats KVM_CAP_NR_CPUS differently from all other + * architectures, as it does not always bound it to + * num_online_cpus(). It should not matter much because this + * is just an advisory value. + */ + r = min_t(unsigned int, num_online_cpus(), + kvm_arm_default_max_vcpus()); break; case KVM_CAP_MAX_VCPUS: case KVM_CAP_MAX_VCPU_ID: From patchwork Tue Nov 16 16:34:39 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12622925 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22D74C433EF for ; Tue, 16 Nov 2021 16:35:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0E9D06108D for ; Tue, 16 Nov 2021 16:35:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234366AbhKPQid (ORCPT ); Tue, 16 Nov 2021 11:38:33 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:43886 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234636AbhKPQia (ORCPT ); Tue, 16 Nov 2021 11:38:30 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1637080532; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=NmiJDhyq+drucaTkVr87beK9OfQhHewmWSpxx8X97oU=; b=Rm7lV5sBnXdRd2CP3Ir4ndyt3a0792I9K5TlCLn6ZXB3AhiAb2WfWT/eQMb+Eeig/xLPZm 1GJu1uw/VBkHbWMOuKc+iuFJzAkaUja3iOH2xuAqmWL1gS8bntO7LhRKpog45K3nZ+otD7 RcySchribG3LVJPnBp30jZQzEyAB3Pk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-561-86hWh_o9PS-9NiTglb70XA-1; Tue, 16 Nov 2021 11:35:29 -0500 X-MC-Unique: 86hWh_o9PS-9NiTglb70XA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E29A5101F004; Tue, 16 Nov 2021 16:35:26 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.192.236]) by smtp.corp.redhat.com (Postfix) with ESMTP id 43C7360C0F; Tue, 16 Nov 2021 16:35:02 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , Eduardo Habkost , Marc Zyngier , Andrew Jones , Huacai Chen , Aleksandar Markovic , Anup Patel , Paul Mackerras , Michael Ellerman , Christian Borntraeger , Janosch Frank , kvm-ppc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/6] KVM: MIPS: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS Date: Tue, 16 Nov 2021 17:34:39 +0100 Message-Id: <20211116163443.88707-3-vkuznets@redhat.com> In-Reply-To: <20211116163443.88707-1-vkuznets@redhat.com> References: <20211116163443.88707-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org It doesn't make sense to return the recommended maximum number of vCPUs which exceeds the maximum possible number of vCPUs. Signed-off-by: Vitaly Kuznetsov --- arch/mips/kvm/mips.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c index 562aa878b266..aa20d074d388 100644 --- a/arch/mips/kvm/mips.c +++ b/arch/mips/kvm/mips.c @@ -1067,7 +1067,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = 1; break; case KVM_CAP_NR_VCPUS: - r = num_online_cpus(); + r = min_t(unsigned int, num_online_cpus(), KVM_MAX_VCPUS); break; case KVM_CAP_MAX_VCPUS: r = KVM_MAX_VCPUS; From patchwork Tue Nov 16 16:34:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12622927 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED386C433F5 for ; Tue, 16 Nov 2021 16:35:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D68D061BFA for ; Tue, 16 Nov 2021 16:35:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234650AbhKPQii (ORCPT ); Tue, 16 Nov 2021 11:38:38 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:44907 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234483AbhKPQig (ORCPT ); Tue, 16 Nov 2021 11:38:36 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1637080539; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=m5C/utbR+RY6tkUQ1/OF5lvFnSyvv5qyaKbzbIqaS0s=; b=DuXc/N1UDrDvnlZEY9puytrYt+wHPb66X3K/EQa02JHBG9aU6Z2pOaACnK2SVWBKqbSctN 3oMz6LXBRJ9MitxaRurlWYiA3kE+oaw52Jewb/PHHAJOM5cBQN1Nzs9CHX2ctYySMB3xST qCBG2RqCIyELXZ9lCTNdO8+RChzkuCo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-507-tdBv9e-9McCF1bk0yXEsmA-1; Tue, 16 Nov 2021 11:35:37 -0500 X-MC-Unique: tdBv9e-9McCF1bk0yXEsmA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 601CF15720; Tue, 16 Nov 2021 16:35:34 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.192.236]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6A71B60C0F; Tue, 16 Nov 2021 16:35:27 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , Eduardo Habkost , Marc Zyngier , Andrew Jones , Huacai Chen , Aleksandar Markovic , Anup Patel , Paul Mackerras , Michael Ellerman , Christian Borntraeger , Janosch Frank , kvm-ppc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 3/6] KVM: PPC: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS Date: Tue, 16 Nov 2021 17:34:40 +0100 Message-Id: <20211116163443.88707-4-vkuznets@redhat.com> In-Reply-To: <20211116163443.88707-1-vkuznets@redhat.com> References: <20211116163443.88707-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org It doesn't make sense to return the recommended maximum number of vCPUs which exceeds the maximum possible number of vCPUs. Signed-off-by: Vitaly Kuznetsov --- arch/powerpc/kvm/powerpc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 8ab90ce8738f..ccac8d5686ff 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -641,9 +641,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) * implementations just count online CPUs. */ if (hv_enabled) - r = num_present_cpus(); + r = min_t(unsigned int, num_present_cpus(), KVM_MAX_VCPUS); else - r = num_online_cpus(); + r = min_t(unsigned int, num_online_cpus(), KVM_MAX_VCPUS); break; case KVM_CAP_MAX_VCPUS: r = KVM_MAX_VCPUS; From patchwork Tue Nov 16 16:34:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12622929 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 245DCC433EF for ; Tue, 16 Nov 2021 16:36:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0DF876108D for ; Tue, 16 Nov 2021 16:36:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234886AbhKPQi4 (ORCPT ); Tue, 16 Nov 2021 11:38:56 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:27258 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234411AbhKPQix (ORCPT ); Tue, 16 Nov 2021 11:38:53 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1637080556; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=UOooTQL4J+pYhtZfN++C64GbB6JN9+KRPPDfDzsojTc=; b=d/za+q+GI+ICRbFDyn7KisUYsI0w2ivB3CUv4HmN/mul4+OLmxh/8LrXKH4tHpsQKrO7zf vduQgFrARCquWl0RjADaU/B8uQ3GAi1CGzxBUxkFLU7RClQe8EMQ/MVG8Jfe4tl/yBHCBt kfklvSMwvNCwPVU8r8x1S0CzCsgtChQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-395-q7Jg4YYEP3ax5ODC0nG46g-1; Tue, 16 Nov 2021 11:35:52 -0500 X-MC-Unique: q7Jg4YYEP3ax5ODC0nG46g-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 61AFC15733; Tue, 16 Nov 2021 16:35:50 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.192.236]) by smtp.corp.redhat.com (Postfix) with ESMTP id C4FB560C0F; Tue, 16 Nov 2021 16:35:35 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , Eduardo Habkost , Marc Zyngier , Andrew Jones , Huacai Chen , Aleksandar Markovic , Anup Patel , Paul Mackerras , Michael Ellerman , Christian Borntraeger , Janosch Frank , kvm-ppc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 4/6] KVM: RISC-V: Cap KVM_CAP_NR_VCPUS by KVM_CAP_MAX_VCPUS Date: Tue, 16 Nov 2021 17:34:41 +0100 Message-Id: <20211116163443.88707-5-vkuznets@redhat.com> In-Reply-To: <20211116163443.88707-1-vkuznets@redhat.com> References: <20211116163443.88707-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org It doesn't make sense to return the recommended maximum number of vCPUs which exceeds the maximum possible number of vCPUs. Signed-off-by: Vitaly Kuznetsov Acked-by: Anup Patel Reviewed-by: Anup Patel --- arch/riscv/kvm/vm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/kvm/vm.c b/arch/riscv/kvm/vm.c index 26399df15b63..fb18af34a4b5 100644 --- a/arch/riscv/kvm/vm.c +++ b/arch/riscv/kvm/vm.c @@ -74,7 +74,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = 1; break; case KVM_CAP_NR_VCPUS: - r = num_online_cpus(); + r = min_t(unsigned int, num_online_cpus(), KVM_MAX_VCPUS); break; case KVM_CAP_MAX_VCPUS: r = KVM_MAX_VCPUS; From patchwork Tue Nov 16 16:34:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12622931 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16A8EC433EF for ; Tue, 16 Nov 2021 16:36:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ECD0B6108D for ; Tue, 16 Nov 2021 16:36:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234835AbhKPQjA (ORCPT ); Tue, 16 Nov 2021 11:39:00 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:25799 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234749AbhKPQi7 (ORCPT ); Tue, 16 Nov 2021 11:38:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1637080562; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=tKE+cntXrkzP99c9RfIwCSUBp3uLto7NMCtdS5oLqy0=; b=VxtbgHl79mPeqGQB3qNCa9C2stjzOwVQJwUGgyKgVWv/Bt7mztqxG2cWdfPPsS3EvahEDL ssAi6QmC1/KsuWBdABLIT/ztoDBK+5gs95l1iM4BdI2Nns3G8IG+WzkIMflCKvUshEEGVv vf3jT9hR88GaTCRMsZY72WJoWbtF0Qw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-512-_nOTq_pZMjC_gzlxlhMDlg-1; Tue, 16 Nov 2021 11:35:58 -0500 X-MC-Unique: _nOTq_pZMjC_gzlxlhMDlg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4C96E1572D; Tue, 16 Nov 2021 16:35:56 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.192.236]) by smtp.corp.redhat.com (Postfix) with ESMTP id D893060C0F; Tue, 16 Nov 2021 16:35:50 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , Eduardo Habkost , Marc Zyngier , Andrew Jones , Huacai Chen , Aleksandar Markovic , Anup Patel , Paul Mackerras , Michael Ellerman , Christian Borntraeger , Janosch Frank , kvm-ppc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 5/6] KVM: s390: Cap KVM_CAP_NR_VCPUS by num_online_cpus() Date: Tue, 16 Nov 2021 17:34:42 +0100 Message-Id: <20211116163443.88707-6-vkuznets@redhat.com> In-Reply-To: <20211116163443.88707-1-vkuznets@redhat.com> References: <20211116163443.88707-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org KVM_CAP_NR_VCPUS is a legacy advisory value which on other architectures return num_online_cpus() caped by KVM_CAP_NR_VCPUS or something else (ppc and arm64 are special cases). On s390, KVM_CAP_NR_VCPUS returns the same as KVM_CAP_MAX_VCPUS and this may turn out to be a bad 'advice'. Switch s390 to returning caped num_online_cpus() too. Acked-by: Christian Borntraeger Signed-off-by: Vitaly Kuznetsov Reviewed-by: Christian Borntraeger --- arch/s390/kvm/kvm-s390.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 6a6dd5e1daf6..1cfe36f6432e 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -585,6 +585,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = KVM_MAX_VCPUS; else if (sclp.has_esca && sclp.has_64bscao) r = KVM_S390_ESCA_CPU_SLOTS; + if (ext == KVM_CAP_NR_VCPUS) + r = min_t(unsigned int, num_online_cpus(), r); break; case KVM_CAP_S390_COW: r = MACHINE_HAS_ESOP; From patchwork Tue Nov 16 16:34:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vitaly Kuznetsov X-Patchwork-Id: 12622935 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9089FC433F5 for ; Tue, 16 Nov 2021 16:36:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 749D661A64 for ; Tue, 16 Nov 2021 16:36:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234127AbhKPQjN (ORCPT ); Tue, 16 Nov 2021 11:39:13 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:38227 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234128AbhKPQjI (ORCPT ); Tue, 16 Nov 2021 11:39:08 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1637080571; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Fzs/tu22nSIiklxyWhqw5I8HgPrSNduRvkzTjwACmGg=; b=CbBZiUZC8qkT9ia1SOJqC+k5n5AEQKClsAo1qHMg8xaF6UOEuYM+k7eX5QOXqrHj+bIsAn O9AKJbb7iDl/xCxjcJ88zfE8AxL2HcQJRuJpxgmkP4lc53ltBKGj9fF/sMBEBxFWfVjDgv b50W55QlYzL8bXp1kN926tHicDX7xaw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-139-kiLU4MXTPMSt6gKSd-U_OQ-1; Tue, 16 Nov 2021 11:36:08 -0500 X-MC-Unique: kiLU4MXTPMSt6gKSd-U_OQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 151D6192203A; Tue, 16 Nov 2021 16:36:02 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.40.192.236]) by smtp.corp.redhat.com (Postfix) with ESMTP id ADD9160C0F; Tue, 16 Nov 2021 16:35:56 +0000 (UTC) From: Vitaly Kuznetsov To: kvm@vger.kernel.org, Paolo Bonzini Cc: Sean Christopherson , Wanpeng Li , Jim Mattson , Eduardo Habkost , Marc Zyngier , Andrew Jones , Huacai Chen , Aleksandar Markovic , Anup Patel , Paul Mackerras , Michael Ellerman , Christian Borntraeger , Janosch Frank , kvm-ppc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 6/6] KVM: x86: Drop arbitraty KVM_SOFT_MAX_VCPUS Date: Tue, 16 Nov 2021 17:34:43 +0100 Message-Id: <20211116163443.88707-7-vkuznets@redhat.com> In-Reply-To: <20211116163443.88707-1-vkuznets@redhat.com> References: <20211116163443.88707-1-vkuznets@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org KVM_CAP_NR_VCPUS is used to get the "recommended" maximum number of VCPUs and arm64/mips/riscv report num_online_cpus(). Powerpc reports either num_online_cpus() or num_present_cpus(), s390 has multiple constants depending on hardware features. On x86, KVM reports an arbitrary value of '710' which is supposed to be the maximum tested value but it's possible to test all KVM_MAX_VCPUS even when there are less physical CPUs available. Drop the arbitrary '710' value and return num_online_cpus() on x86 as well. The recommendation will match other architectures and will mean 'no CPU overcommit'. For reference, QEMU only queries KVM_CAP_NR_VCPUS to print a warning when the requested vCPU number exceeds it. The static limit of '710' is quite weird as smaller systems with just a few physical CPUs should certainly "recommend" less. Suggested-by: Eduardo Habkost Signed-off-by: Vitaly Kuznetsov --- arch/x86/include/asm/kvm_host.h | 1 - arch/x86/kvm/x86.c | 2 +- 2 files changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 88fce6ab4bbd..0232a00598f2 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -38,7 +38,6 @@ #define __KVM_HAVE_ARCH_VCPU_DEBUGFS #define KVM_MAX_VCPUS 1024 -#define KVM_SOFT_MAX_VCPUS 710 /* * In x86, the VCPU ID corresponds to the APIC ID, and APIC IDs diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ac83d873d65b..18a00a7c23bc 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4137,7 +4137,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = !static_call(kvm_x86_cpu_has_accelerated_tpr)(); break; case KVM_CAP_NR_VCPUS: - r = KVM_SOFT_MAX_VCPUS; + r = min_t(unsigned int, num_online_cpus(), KVM_MAX_VCPUS); break; case KVM_CAP_MAX_VCPUS: r = KVM_MAX_VCPUS;