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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id C8281C43334 for ; Thu, 9 Jun 2022 14:18:11 +0000 (UTC) Received: from localhost ([::1]:52848 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nzIzC-0008Oh-OD for qemu-devel@archiver.kernel.org; Thu, 09 Jun 2022 10:18:10 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58116) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nzHBZ-0005HU-2f for qemu-devel@nongnu.org; Thu, 09 Jun 2022 08:22:49 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:24405) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nzHBW-0006zv-6h for qemu-devel@nongnu.org; Thu, 09 Jun 2022 08:22:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1654777365; 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: in-reply-to:in-reply-to:references:references; bh=Wl/djausEhOtuoQoTTWpa7r4GRYtWBpbw6DGvHJ9jgg=; b=RE1ORZ9dBqM5EC9KljqpVFIAfLiweC3D5v76LC/Kjlft8phB7f7XJ4Twy7zKiWcbZ2ku58 gHPdMYDjLR9CL0JZwm9YgUM3vb/++4LBWmMSUKHuOo2ih6drhzwe88ZnP8S7chRMK2sR4M ToA6tChkDfhcD0hFX6PzlWSeu7QHfVo= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-528-Dk0oOYjOOuOc57v-AqZ_dg-1; Thu, 09 Jun 2022 08:22:42 -0400 X-MC-Unique: Dk0oOYjOOuOc57v-AqZ_dg-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B7621397968E for ; Thu, 9 Jun 2022 12:22:41 +0000 (UTC) Received: from localhost (unknown [10.39.192.115]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6CA5D456CD9; Thu, 9 Jun 2022 12:22:41 +0000 (UTC) From: Cornelia Huck To: Paolo Bonzini , qemu-devel@nongnu.org Cc: mst@redhat.com, thuth@redhat.com Subject: Re: [PATCH 4/4] virtio-mmio: cleanup reset In-Reply-To: <20220609091534.1416909-5-pbonzini@redhat.com> Organization: Red Hat GmbH References: <20220609091534.1416909-1-pbonzini@redhat.com> <20220609091534.1416909-5-pbonzini@redhat.com> User-Agent: Notmuch/0.36 (https://notmuchmail.org) Date: Thu, 09 Jun 2022 14:22:40 +0200 Message-ID: <87ilpa9gbz.fsf@redhat.com> MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.85 on 10.11.54.10 Received-SPF: pass client-ip=170.10.133.124; envelope-from=cohuck@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Jun 09 2022, Paolo Bonzini wrote: > Make virtio_mmio_soft_reset reset the virtio device, which is performed by > both the "soft" and the "hard" reset; and then call virtio_mmio_soft_reset > from virtio_mmio_reset to emphasize that the latter is a superset of the > former. > > Signed-off-by: Paolo Bonzini > --- > hw/virtio/virtio-mmio.c | 17 ++++++++--------- > 1 file changed, 8 insertions(+), 9 deletions(-) > > diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c > index 6d81a26473..d240efef97 100644 > --- a/hw/virtio/virtio-mmio.c > +++ b/hw/virtio/virtio-mmio.c > @@ -72,12 +72,12 @@ static void virtio_mmio_soft_reset(VirtIOMMIOProxy *proxy) > { > int i; > > - if (proxy->legacy) { > - return; > - } > + virtio_bus_reset(&proxy->bus); > > - for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { > - proxy->vqs[i].enabled = 0; > + if (!proxy->legacy) { > + for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { > + proxy->vqs[i].enabled = 0; > + } > } > } The more I look at this, the more confused I get. The current code calls soft_reset when the driver sets the status to 0, after already having called virtio_reset(). But doesn't virtio_reset() ultimately already trigger the virtio-mmio reset routine, which sets enabled to 0 for all queues? Why do that again? (And why is soft_reset a "soft reset"?) Maybe I'm missing something obvious, or it is simply -ENOCOFFEE on my side. > > @@ -376,7 +376,7 @@ static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value, > return; > } > if (value == 0) { > - virtio_bus_reset(&vdev->bus); > + virtio_mmio_soft_reset(proxy); > } else { > virtio_queue_set_addr(vdev, vdev->queue_sel, > value << proxy->guest_page_shift); > @@ -432,7 +432,6 @@ static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value, > } > > if (vdev->status == 0) { > - virtio_reset(vdev); > virtio_mmio_soft_reset(proxy); > } > break; > @@ -627,7 +626,8 @@ static void virtio_mmio_reset(DeviceState *d) > VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d); > int i; > > - virtio_bus_reset(&proxy->bus); > + virtio_mmio_soft_reset(proxy); > + > proxy->host_features_sel = 0; > proxy->guest_features_sel = 0; > proxy->guest_page_shift = 0; > @@ -636,7 +636,6 @@ static void virtio_mmio_reset(DeviceState *d) > proxy->guest_features[0] = proxy->guest_features[1] = 0; > > for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { > - proxy->vqs[i].enabled = 0; > proxy->vqs[i].num = 0; > proxy->vqs[i].desc[0] = proxy->vqs[i].desc[1] = 0; > proxy->vqs[i].avail[0] = proxy->vqs[i].avail[1] = 0;