From patchwork Thu Jun 6 16:54:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 10980121 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CFE8B14E5 for ; Thu, 6 Jun 2019 16:55:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BCFFD2892D for ; Thu, 6 Jun 2019 16:55:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B0D9B28A13; Thu, 6 Jun 2019 16:55:45 +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=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 63EE52892D for ; Thu, 6 Jun 2019 16:55:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=AMoybmhtK5WLDg5gFgi5U60ZusR06IeWvtu9kcxz2PE=; b=ta07l0SeEcehqd sxOkKUghy/Ip47wuvDVDLchg6RWLHAW3fQy7wJs7h6pTtolkctzbgHcDSIU2k1i8z6qwiQZRq06mw BNuT5yTfFXLq28aaCNZE5loJfnVozKoAtkZK4Ya5zrlu3wqY8wHZz046Ijs7i3tz+vXI4R80tlmQC DfeJ7POEWVFFQ26ayXnBzerNtn/570q+aWF9eQK28itvQRY9tG/Ia09RuXGvwUrWXak/xfBQOQ6oS uU7gEIU9w0MNjkwVvUYJswSG6m1Fu665qvDWyikzbNW7njflprobPIj9DlZOrKdiPExU+yYx1gT3j cb1WuCI/Mpsk4eGEEXwQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hYvft-0006TJ-2S; Thu, 06 Jun 2019 16:55:37 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hYvfT-0005sv-Hj for linux-arm-kernel@lists.infradead.org; Thu, 06 Jun 2019 16:55:14 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 61377165C; Thu, 6 Jun 2019 09:55:11 -0700 (PDT) Received: from filthy-habits.cambridge.arm.com (filthy-habits.cambridge.arm.com [10.1.197.61]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 92B173F690; Thu, 6 Jun 2019 09:55:09 -0700 (PDT) From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Subject: [PATCH 3/8] KVM: arm/arm64: vgic-its: Cache successful MSI->LPI translation Date: Thu, 6 Jun 2019 17:54:50 +0100 Message-Id: <20190606165455.162478-4-marc.zyngier@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190606165455.162478-1-marc.zyngier@arm.com> References: <20190606165455.162478-1-marc.zyngier@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190606_095511_837882_B5ECE9DB X-CRM114-Status: GOOD ( 12.82 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Suzuki K Poulose , "Raslan, KarimAllah" , Julien Thierry , Christoffer Dall , Eric Auger , James Morse , Zenghui Yu Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP On a successful translation, preserve the parameters in the LPI translation cache. Each translation is reusing the last slot in the list, naturally evincting the least recently used entry. Signed-off-by: Marc Zyngier --- virt/kvm/arm/vgic/vgic-its.c | 41 ++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index 5758504fd934..bc370b6c5afa 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -538,6 +538,45 @@ static unsigned long vgic_mmio_read_its_idregs(struct kvm *kvm, return 0; } +static void vgic_its_cache_translation(struct kvm *kvm, struct vgic_its *its, + u32 devid, u32 eventid, + struct vgic_irq *irq) +{ + struct vgic_dist *dist = &kvm->arch.vgic; + struct vgic_translation_cache_entry *cte; + unsigned long flags; + + /* Do not cache a directly injected interrupt */ + if (irq->hw) + return; + + raw_spin_lock_irqsave(&dist->lpi_list_lock, flags); + + /* Always reuse the last entry (LRU policy) */ + cte = list_last_entry(&dist->lpi_translation_cache, + typeof(*cte), entry); + + /* + * Caching the translation implies having an extra reference + * to the interrupt, so drop the potential reference on what + * was in the cache, and increment it on the new interrupt. + */ + if (cte->irq) + __vgic_put_lpi_locked(kvm, cte->irq); + + vgic_get_irq_kref(irq); + + cte->db = its->vgic_its_base + GITS_TRANSLATER; + cte->devid = devid; + cte->eventid = eventid; + cte->irq = irq; + + /* Move the new translation to the head of the list */ + list_move(&cte->entry, &dist->lpi_translation_cache); + + raw_spin_unlock_irqrestore(&dist->lpi_list_lock, flags); +} + int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its, u32 devid, u32 eventid, struct vgic_irq **irq) { @@ -558,6 +597,8 @@ int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its, if (!vcpu->arch.vgic_cpu.lpis_enabled) return -EBUSY; + vgic_its_cache_translation(kvm, its, devid, eventid, ite->irq); + *irq = ite->irq; return 0; }