From patchwork Thu Apr 16 20:00:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Duyck X-Patchwork-Id: 1271879 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=G492WGL1; dkim-atps=neutral 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 ozlabs.org (Postfix) with ESMTPS id 49398v09N1z9sQx for ; Fri, 17 Apr 2020 06:01:34 +1000 (AEST) Received: from localhost ([::1]:38762 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jPAhX-000599-H3 for incoming@patchwork.ozlabs.org; Thu, 16 Apr 2020 16:01:31 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56171) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jPAgr-000526-1n for qemu-devel@nongnu.org; Thu, 16 Apr 2020 16:00:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jPAgo-0000U4-SA for qemu-devel@nongnu.org; Thu, 16 Apr 2020 16:00:48 -0400 Received: from mail-pl1-x644.google.com ([2607:f8b0:4864:20::644]:38294) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1jPAgo-0000Tm-Lj for qemu-devel@nongnu.org; Thu, 16 Apr 2020 16:00:46 -0400 Received: by mail-pl1-x644.google.com with SMTP id w3so25945plz.5 for ; Thu, 16 Apr 2020 13:00:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:from:to:cc:date:message-id:in-reply-to:references :user-agent:mime-version:content-transfer-encoding; bh=wvk7nigxCNm3PB+AvD69Criz9Bq5lWke+Bvc71+/U/E=; b=G492WGL1cz1eCnfFjL3KlDJye+n7mj0KjCq8Nzpu6Qb1oLWeFtPrRWAIOp7SfXwDb8 GrwQC6K+Utk8gi8jQ0MQxePLGjL0l4JN4EdJpot9knqFAgSElITcELsqkUMzxSo/XUy6 VjA2PCZ+fw3t3Zkdvy1tAJwz7JBliK+yBpXQzE3o39rNf5E0cmc386HmQhww6O5Z3jvl yoR9Hcb30TKpJZihO+ZOr2JtBd85V6xmhyOKlhe6ieMppjWEcb0vKynUxDvGoyXzH8R/ XLWdcFzfwTlX2/76iOtm+2FuZnjCLQoeE+knN901KFaTPBoq7ifrOnQcUDzvV8xZubN1 VBZw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:date:message-id:in-reply-to :references:user-agent:mime-version:content-transfer-encoding; bh=wvk7nigxCNm3PB+AvD69Criz9Bq5lWke+Bvc71+/U/E=; b=tn+xkaldNd40Q52Ehj/JsrO+Yv1EZBA5EkEr0c2F4KoCkbgI1nZPbEMM8677kqFc0g TCpJZq2WiHWhhFUcUEciTPjbQ7ilMXyDEPMtMxYybmCSo9OLkKuGbYgaZxI08yUH5+rR 4zbuHwFd++eO37qKBYxTV5MJ/QMxXWi2SAkHaLGD3ODkfKgcAkFpC3KSdEuPxYqANxqg fAo6jSlVEr5oLdrW7pEQs7xUBzif5DyfgdfnVzgzIC4oO4F7NqoLTe+ULrxXYV0qXIif I8lLVm9pI1Trv7JGF0i26AJob3/6s92RItkPFudzBUJugOTDjgffPWCmDbpmWTzMPvPL MWqA== X-Gm-Message-State: AGi0PuaLIJCMC4fHhcK97aRVm/vEL++T5OAUZIR+XOO0ZIYflY/rm4Q4 gI/H1hy2jwhlMPLW9SZNeQA= X-Google-Smtp-Source: APiQypKJLAm0D1gjhTifvaKp99X2/3SU6AyhBgMF+2kUC0JERsXYS1f3IaI10COM6csIAQdV0BbQvA== X-Received: by 2002:a17:902:fe90:: with SMTP id x16mr11549082plm.295.1587067245627; Thu, 16 Apr 2020 13:00:45 -0700 (PDT) Received: from localhost.localdomain ([2001:470:b:9c3:9e5c:8eff:fe4f:f2d0]) by smtp.gmail.com with ESMTPSA id a13sm3322899pjq.0.2020.04.16.13.00.43 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 16 Apr 2020 13:00:43 -0700 (PDT) Subject: [PATCH v20 QEMU 3/5] virtio-balloon: Implement support for page poison tracking feature From: Alexander Duyck To: david@redhat.com, mst@redhat.com Date: Thu, 16 Apr 2020 13:00:42 -0700 Message-ID: <20200416200042.13144.65487.stgit@localhost.localdomain> In-Reply-To: <20200416195641.13144.16955.stgit@localhost.localdomain> References: <20200416195641.13144.16955.stgit@localhost.localdomain> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:4864:20::644 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: virtio-dev@lists.oasis-open.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Alexander Duyck We need to make certain to advertise support for page poison tracking if we want to actually get data on if the guest will be poisoning pages. So if free page hinting is active we should add page poisoning support and let the guest disable it if it isn't using it. Page poisoning will result in a page being dirtied on free. As such we cannot really avoid having to copy the page at least one more time since we will need to write the poison value to the destination. As such we can just ignore free page hinting if page poisoning is enabled as it will actually reduce the work we have to do. Signed-off-by: Alexander Duyck --- hw/virtio/virtio-balloon.c | 27 +++++++++++++++++++++++++++ include/hw/virtio/virtio-balloon.h | 1 + 2 files changed, 28 insertions(+) diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c index a1d6fb52c876..19d587fd05cb 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -531,6 +531,23 @@ static void virtio_balloon_free_page_start(VirtIOBalloon *s) return; } + /* + * If page poisoning is enabled then we probably shouldn't bother with + * the hinting since the poisoning will dirty the page and invalidate + * the work we are doing anyway. + * + * If at some point in the future the implementation is changed in the + * guest we would still have issues as the poison would need to be + * applied to the last state of the page on the remote end. + * + * To do that we could improve upon this current implementation by + * migrating a poison/zero page if the page is flagged as dirty instead + * of simply skipping it. + */ + if (virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) { + return; + } + if (s->free_page_hint_cmd_id == UINT_MAX) { s->free_page_hint_cmd_id = VIRTIO_BALLOON_FREE_PAGE_HINT_CMD_ID_MIN; @@ -634,6 +651,7 @@ static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data) config.num_pages = cpu_to_le32(dev->num_pages); config.actual = cpu_to_le32(dev->actual); + config.poison_val = cpu_to_le32(dev->poison_val); if (dev->free_page_hint_status == FREE_PAGE_HINT_S_REQUESTED) { config.free_page_hint_cmd_id = @@ -697,6 +715,10 @@ static void virtio_balloon_set_config(VirtIODevice *vdev, qapi_event_send_balloon_change(vm_ram_size - ((ram_addr_t) dev->actual << VIRTIO_BALLOON_PFN_SHIFT)); } + dev->poison_val = 0; + if (virtio_vdev_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) { + dev->poison_val = le32_to_cpu(config.poison_val); + } trace_virtio_balloon_set_config(dev->actual, oldactual); } @@ -706,6 +728,9 @@ static uint64_t virtio_balloon_get_features(VirtIODevice *vdev, uint64_t f, VirtIOBalloon *dev = VIRTIO_BALLOON(vdev); f |= dev->host_features; virtio_add_feature(&f, VIRTIO_BALLOON_F_STATS_VQ); + if (virtio_has_feature(f, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) { + virtio_add_feature(&f, VIRTIO_BALLOON_F_PAGE_POISON); + } return f; } @@ -854,6 +879,8 @@ static void virtio_balloon_device_reset(VirtIODevice *vdev) g_free(s->stats_vq_elem); s->stats_vq_elem = NULL; } + + s->poison_val = 0; } static void virtio_balloon_set_status(VirtIODevice *vdev, uint8_t status) diff --git a/include/hw/virtio/virtio-balloon.h b/include/hw/virtio/virtio-balloon.h index 108cff97e71a..3ca2a78e1aca 100644 --- a/include/hw/virtio/virtio-balloon.h +++ b/include/hw/virtio/virtio-balloon.h @@ -70,6 +70,7 @@ typedef struct VirtIOBalloon { uint32_t host_features; bool qemu_4_0_config_size; + uint32_t poison_val; } VirtIOBalloon; #endif