From patchwork Sun Dec 6 17:43:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Igor Druzhinin X-Patchwork-Id: 11954209 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,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 BA8C2C433FE for ; Sun, 6 Dec 2020 18:05:47 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 65EAA2311B for ; Sun, 6 Dec 2020 18:05:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 65EAA2311B Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=citrix.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.45732.81143 (Exim 4.92) (envelope-from ) id 1klyPa-0000qG-3p; Sun, 06 Dec 2020 18:05:30 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 45732.81143; Sun, 06 Dec 2020 18:05:30 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1klyPZ-0000q9-WD; Sun, 06 Dec 2020 18:05:30 +0000 Received: by outflank-mailman (input) for mailman id 45732; Sun, 06 Dec 2020 18:05:28 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1klyPY-0000q4-DF for xen-devel@lists.xenproject.org; Sun, 06 Dec 2020 18:05:28 +0000 Received: from esa2.hc3370-68.iphmx.com (unknown [216.71.145.153]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id b2ff1f83-c7cb-4d53-89fa-cd580fa1c340; Sun, 06 Dec 2020 18:05:27 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: b2ff1f83-c7cb-4d53-89fa-cd580fa1c340 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1607277926; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=hPEg/xcTyqwf1mlGpj4j/c1lKeAMXPZhJ+mEGlPUrac=; b=POgSskPi3pWHvJYa1YQrjisfGMYSmd618LEbIN4kP5ondjC0bcduSiRN M90UEVfXASA7CnXHTSGDhYDDXU1Nu9Mi9hrGOx3CAH6iMigD1E1gMetcD d9HtuS2OOMVs+uKdQCx2oNbv/Mkdq40dLBLuExMVbfw+oLgyIZBZFh8Qo 8=; Authentication-Results: esa2.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none IronPort-SDR: tv/Uab4Qve+f99T5GDTW5BPOIqiy8je4JaAvyItLKm4NppSbNzyvUXGRS7TtSbsCI9zNztqPZR xBq0bqR7FW5emIgLGC4GfpSYceSF8yEl5XG9IZAd079sHA/tytbLxKYChZ/wBnCEXTlhcCFyol BpWdztvJayZ/DCIZNyTWs1skxWGEfZGWGokPBxfwInRl5coz+ssk2CvqadfrVU61uIQPs+0WPu wm/hWkB3QVti22pKPLrbp+hrypa6ogH8hLp1tPr7q/DCdNtoy+QGN9VwLnfsThmU7HQXe4Fc3u UiM= X-SBRS: 5.1 X-MesageID: 32638347 X-Ironport-Server: esa2.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.78,397,1599537600"; d="scan'208";a="32638347" From: Igor Druzhinin To: CC: , , , , , , , , "Igor Druzhinin" Subject: [PATCH v3 2/2] x86/IRQ: allocate guest array of max size only for shareable IRQs Date: Sun, 6 Dec 2020 17:43:07 +0000 Message-ID: <1607276587-19231-2-git-send-email-igor.druzhinin@citrix.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1607276587-19231-1-git-send-email-igor.druzhinin@citrix.com> References: <1607276587-19231-1-git-send-email-igor.druzhinin@citrix.com> MIME-Version: 1.0 ... and increase default "irq-max-guests" to 32. It's not necessary to have an array of a size more than 1 for non-shareable IRQs and it might impact scalability in case of high "irq-max-guests" values being used - every IRQ in the system including MSIs would be supplied with an array of that size. Since it's now less impactful to use higher "irq-max-guests" value - bump the default to 32. That should give more headroom for future systems. Signed-off-by: Igor Druzhinin Reviewed-by: Jan Beulich --- New in v2. Based on Jan's suggestion. Changes in v3: - almost none since I prefer the clarity of the code as is --- docs/misc/xen-command-line.pandoc | 2 +- xen/arch/x86/irq.c | 7 ++++--- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/docs/misc/xen-command-line.pandoc b/docs/misc/xen-command-line.pandoc index 53e676b..f7db2b6 100644 --- a/docs/misc/xen-command-line.pandoc +++ b/docs/misc/xen-command-line.pandoc @@ -1644,7 +1644,7 @@ This option is ignored in **pv-shim** mode. ### irq-max-guests (x86) > `= ` -> Default: `16` +> Default: `32` Maximum number of guests any individual IRQ could be shared between, i.e. a limit on the number of guests it is possible to start each having diff --git a/xen/arch/x86/irq.c b/xen/arch/x86/irq.c index 4fd0578..a088818 100644 --- a/xen/arch/x86/irq.c +++ b/xen/arch/x86/irq.c @@ -440,7 +440,7 @@ int __init init_irq_data(void) irq_to_desc(irq)->irq = irq; if ( !irq_max_guests ) - irq_max_guests = 16; + irq_max_guests = 32; #ifdef CONFIG_PV /* Never allocate the hypercall vector or Linux/BSD fast-trap vector. */ @@ -1540,6 +1540,7 @@ int pirq_guest_bind(struct vcpu *v, struct pirq *pirq, int will_share) unsigned int irq; struct irq_desc *desc; irq_guest_action_t *action, *newaction = NULL; + unsigned char max_nr_guests = will_share ? irq_max_guests : 1; int rc = 0; WARN_ON(!spin_is_locked(&v->domain->event_lock)); @@ -1571,7 +1572,7 @@ int pirq_guest_bind(struct vcpu *v, struct pirq *pirq, int will_share) { spin_unlock_irq(&desc->lock); if ( (newaction = xmalloc_flex_struct(irq_guest_action_t, guest, - irq_max_guests)) != NULL && + max_nr_guests)) != NULL && zalloc_cpumask_var(&newaction->cpu_eoi_map) ) goto retry; xfree(newaction); @@ -1640,7 +1641,7 @@ int pirq_guest_bind(struct vcpu *v, struct pirq *pirq, int will_share) goto retry; } - if ( action->nr_guests == irq_max_guests ) + if ( action->nr_guests >= max_nr_guests ) { printk(XENLOG_G_INFO "Cannot bind IRQ%d to dom%pd: already at max share %u ",