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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 230ABC54FCB for ; Mon, 27 Apr 2020 14:17:56 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id C3A4B206B9 for ; Mon, 27 Apr 2020 14:17:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="pzItXPTz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C3A4B206B9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 4CF234B0BE; Mon, 27 Apr 2020 10:17:55 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@kernel.org Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Ey5ewi19m5Ek; Mon, 27 Apr 2020 10:17:54 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 2E5154B0AC; Mon, 27 Apr 2020 10:17:54 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 694164B0AC for ; Mon, 27 Apr 2020 10:17:52 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id wsy764sIS5zx for ; Mon, 27 Apr 2020 10:17:51 -0400 (EDT) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 853B64A95C for ; Mon, 27 Apr 2020 10:17:51 -0400 (EDT) Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 63460206B6; Mon, 27 Apr 2020 14:17:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587997070; bh=CSSnDMC5PzLW9Ty/t6vNkRAXv5DRYOcczqebb1dCB8w=; h=From:To:Cc:Subject:Date:From; b=pzItXPTziBM5cfmNXO7kDO4LK36WFULj6A7TjQQnL4oRHAcho6MAGywU/VzBc2dPh 4FQeR5lP2RXyYOKWneuAeGRzQaBrFaATmt9Eun8Qbn6OX0fADcX3ZpLeJbi9UEMRNu 70GmJmp62lCh+0GfHqpNab9UNF1d11/vl78T4whA= Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jT4Zw-006kdf-Qq; Mon, 27 Apr 2020 15:17:48 +0100 From: Marc Zyngier To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Subject: [PATCH][kvmtool] kvm: Request VM specific limits instead of system-wide ones Date: Mon, 27 Apr 2020 15:17:38 +0100 Message-Id: <20200427141738.285217-1-maz@kernel.org> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, will@kernel.org, Andre.Przywara@arm.com, ardb@kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Cc: Andre Przywara , Will Deacon , Ard Biesheuvel X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On arm64, the maximum number of vcpus is constrained by the type of interrupt controller that has been selected (GICv2 imposes a limit of 8 vcpus, while GICv3 currently has a limit of 512). It is thus important to request this limit on the VM file descriptor rather than on the one that corresponds to /dev/kvm, as the latter is likely to return something that doesn't take the constraints into account. Reported-by: Ard Biesheuvel Signed-off-by: Marc Zyngier --- kvm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kvm.c b/kvm.c index e327541..3d5173d 100644 --- a/kvm.c +++ b/kvm.c @@ -406,7 +406,7 @@ int kvm__recommended_cpus(struct kvm *kvm) { int ret; - ret = ioctl(kvm->sys_fd, KVM_CHECK_EXTENSION, KVM_CAP_NR_VCPUS); + ret = ioctl(kvm->vm_fd, KVM_CHECK_EXTENSION, KVM_CAP_NR_VCPUS); if (ret <= 0) /* * api.txt states that if KVM_CAP_NR_VCPUS does not exist, @@ -421,7 +421,7 @@ int kvm__max_cpus(struct kvm *kvm) { int ret; - ret = ioctl(kvm->sys_fd, KVM_CHECK_EXTENSION, KVM_CAP_MAX_VCPUS); + ret = ioctl(kvm->vm_fd, KVM_CHECK_EXTENSION, KVM_CAP_MAX_VCPUS); if (ret <= 0) ret = kvm__recommended_cpus(kvm); -- 2.26.2 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm 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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E7BEC54FD0 for ; Mon, 27 Apr 2020 14:17:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36AF2206CD for ; Mon, 27 Apr 2020 14:17:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587997072; bh=CSSnDMC5PzLW9Ty/t6vNkRAXv5DRYOcczqebb1dCB8w=; h=From:To:Cc:Subject:Date:List-ID:From; b=i7Z7E6ZtrUyHJSYVekxy2AZCfXB61Azqf4OnZuip3OFZdyBsq/iavXw/kg6unn4DV 5m+ZCFHECNM4LEG71LRsu0uwZX1YAFbQihqNP/U8tzcP51uy/WYCDdNNN/Yi546hpD ps1VuXWbEDjX/Ahpu/iIq1ea1sm49fr/jxh/XL+k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727943AbgD0ORv (ORCPT ); Mon, 27 Apr 2020 10:17:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:44442 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726651AbgD0ORv (ORCPT ); Mon, 27 Apr 2020 10:17:51 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 63460206B6; Mon, 27 Apr 2020 14:17:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587997070; bh=CSSnDMC5PzLW9Ty/t6vNkRAXv5DRYOcczqebb1dCB8w=; h=From:To:Cc:Subject:Date:From; b=pzItXPTziBM5cfmNXO7kDO4LK36WFULj6A7TjQQnL4oRHAcho6MAGywU/VzBc2dPh 4FQeR5lP2RXyYOKWneuAeGRzQaBrFaATmt9Eun8Qbn6OX0fADcX3ZpLeJbi9UEMRNu 70GmJmp62lCh+0GfHqpNab9UNF1d11/vl78T4whA= Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jT4Zw-006kdf-Qq; Mon, 27 Apr 2020 15:17:48 +0100 From: Marc Zyngier To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: James Morse , Julien Thierry , Suzuki K Poulose , Will Deacon , Andre Przywara , Ard Biesheuvel Subject: [PATCH][kvmtool] kvm: Request VM specific limits instead of system-wide ones Date: Mon, 27 Apr 2020 15:17:38 +0100 Message-Id: <20200427141738.285217-1-maz@kernel.org> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, will@kernel.org, Andre.Przywara@arm.com, ardb@kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On arm64, the maximum number of vcpus is constrained by the type of interrupt controller that has been selected (GICv2 imposes a limit of 8 vcpus, while GICv3 currently has a limit of 512). It is thus important to request this limit on the VM file descriptor rather than on the one that corresponds to /dev/kvm, as the latter is likely to return something that doesn't take the constraints into account. Reported-by: Ard Biesheuvel Signed-off-by: Marc Zyngier --- kvm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kvm.c b/kvm.c index e327541..3d5173d 100644 --- a/kvm.c +++ b/kvm.c @@ -406,7 +406,7 @@ int kvm__recommended_cpus(struct kvm *kvm) { int ret; - ret = ioctl(kvm->sys_fd, KVM_CHECK_EXTENSION, KVM_CAP_NR_VCPUS); + ret = ioctl(kvm->vm_fd, KVM_CHECK_EXTENSION, KVM_CAP_NR_VCPUS); if (ret <= 0) /* * api.txt states that if KVM_CAP_NR_VCPUS does not exist, @@ -421,7 +421,7 @@ int kvm__max_cpus(struct kvm *kvm) { int ret; - ret = ioctl(kvm->sys_fd, KVM_CHECK_EXTENSION, KVM_CAP_MAX_VCPUS); + ret = ioctl(kvm->vm_fd, KVM_CHECK_EXTENSION, KVM_CAP_MAX_VCPUS); if (ret <= 0) ret = kvm__recommended_cpus(kvm); -- 2.26.2