From patchwork Mon Mar 15 19:48:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eugenio Perez Martin X-Patchwork-Id: 12140587 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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 A4555C433E0 for ; Mon, 15 Mar 2021 19:59:26 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 4171664DDF for ; Mon, 15 Mar 2021 19:59:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4171664DDF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50182 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lLtN7-0001FM-Av for qemu-devel@archiver.kernel.org; Mon, 15 Mar 2021 15:59:25 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37868) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lLtE3-0005ve-M2 for qemu-devel@nongnu.org; Mon, 15 Mar 2021 15:50:04 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:27116) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lLtE2-0004Fh-1L for qemu-devel@nongnu.org; Mon, 15 Mar 2021 15:50:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615837801; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=UiuTlgOtfMbdtiwceqwHYXYl3zo3bRNZ7YUjgCumRxI=; b=Wia2EJmYbkAcKaPDdcKFageLSt6M/LX94Jy4gxer/lqqu4Z1plKUFiG0wOH2BPK40rjhqs dJip/5z1eci/+mUkOofz856GRzkcO+CpYQytx1BwXLtvizcAtZjlM2mm8llAufzwvx50Tf byIEygZ86l2PkbBd0AGUwBoh4oDDPhE= 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-251-v1DqsurKN0-K1MpbphjFng-1; Mon, 15 Mar 2021 15:49:59 -0400 X-MC-Unique: v1DqsurKN0-K1MpbphjFng-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BC049801597; Mon, 15 Mar 2021 19:49:57 +0000 (UTC) Received: from eperezma.remote.csb (ovpn-112-173.ams2.redhat.com [10.36.112.173]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4B46B5F9B8; Mon, 15 Mar 2021 19:49:54 +0000 (UTC) From: =?utf-8?q?Eugenio_P=C3=A9rez?= To: qemu-devel@nongnu.org Subject: [RFC v2 13/13] vhost: Use VRING_AVAIL_F_NO_INTERRUPT at device call on shadow virtqueue Date: Mon, 15 Mar 2021 20:48:42 +0100 Message-Id: <20210315194842.277740-14-eperezma@redhat.com> In-Reply-To: <20210315194842.277740-1-eperezma@redhat.com> References: <20210315194842.277740-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eperezma@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; envelope-from=eperezma@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.25, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Parav Pandit , "Michael S. Tsirkin" , Guru Prasad , Jason Wang , Juan Quintela , Markus Armbruster , virtualization@lists.linux-foundation.org, Harpreet Singh Anand , Xiao W Wang , Eli Cohen , Stefano Garzarella , Michael Lilja , Jim Harford , Rob Miller Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Signed-off-by: Eugenio Pérez --- hw/virtio/vhost-shadow-virtqueue.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index 7df98fc43f..e3879a4622 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -71,10 +71,35 @@ typedef struct VhostShadowVirtqueue { /* Next head to consume from device */ uint16_t used_idx; + /* Cache for the exposed notification flag */ + bool notification; + /* Descriptors copied from guest */ vring_desc_t descs[]; } VhostShadowVirtqueue; +static void vhost_shadow_vq_set_notification(VhostShadowVirtqueue *svq, + bool enable) +{ + uint16_t notification_flag; + + if (svq->notification == enable) { + return; + } + + notification_flag = virtio_tswap16(svq->vdev, VRING_AVAIL_F_NO_INTERRUPT); + + svq->notification = enable; + if (enable) { + svq->vring.avail->flags &= ~notification_flag; + } else { + svq->vring.avail->flags |= notification_flag; + } + + /* Make sure device reads our flag */ + smp_mb(); +} + static void vhost_vring_write_descs(VhostShadowVirtqueue *svq, const struct iovec *iovec, size_t num, bool more_descs, bool write) @@ -251,7 +276,7 @@ static void vhost_shadow_vq_handle_call_no_test(EventNotifier *n) do { unsigned i = 0; - /* TODO: Use VRING_AVAIL_F_NO_INTERRUPT */ + vhost_shadow_vq_set_notification(svq, false); while (true) { g_autofree VirtQueueElement *elem = vhost_shadow_vq_get_buf(svq); if (!elem) { @@ -269,6 +294,7 @@ static void vhost_shadow_vq_handle_call_no_test(EventNotifier *n) svq->masked_notifier.signaled = true; event_notifier_set(svq->masked_notifier.n); } + vhost_shadow_vq_set_notification(svq, true); } while (vhost_shadow_vq_more_used(svq)); if (masked_notifier) {