From patchwork Thu Aug 9 14:07:20 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 176117 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id BA43D2C00CE for ; Fri, 10 Aug 2012 00:07:58 +1000 (EST) Received: from localhost ([::1]:51819 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SzTP2-0005AN-Q2 for incoming@patchwork.ozlabs.org; Thu, 09 Aug 2012 10:07:56 -0400 Received: from eggs.gnu.org ([208.118.235.92]:39893) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SzTOl-0004pt-Pz for qemu-devel@nongnu.org; Thu, 09 Aug 2012 10:07:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SzTOk-0004aM-Q3 for qemu-devel@nongnu.org; Thu, 09 Aug 2012 10:07:39 -0400 Received: from mail-gh0-f173.google.com ([209.85.160.173]:38794) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SzTOk-0004ZQ-Lm for qemu-devel@nongnu.org; Thu, 09 Aug 2012 10:07:38 -0400 Received: by mail-gh0-f173.google.com with SMTP id r17so445875ghr.4 for ; Thu, 09 Aug 2012 07:07:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; bh=XiCqkggLfkBC76GfYZN0puCwmAikLT41xNFeKF8GAss=; b=sqZo6a+KWWaiuP6eV75yYljr4GkeBrb1fFQCh2CLcofLPrYP6S7N8aNqF3xAJpACf/ DRWksKBIPzA5g2wekcENdNZJwnOKg0AHjwWRop0ZB2X0i78+mjIUfRWs2HH430Keshp/ owOdLGJ9EYHDMLbX8EL10JUJFiif4OIXsSkFpBo/c3kFSejs+gHY2JWreSmOWZFbfxLE 84ZtNe/2L0e8sOktodj7M/yIxgduyQftEsMI4DU3HHdMLYtbBznyEuLKRpv41Ie71yx5 3Qs6XZ1oHsfcbciNVMcCPlrqwXUTlNOq9/r6ogScqld6UlUp3BFCqFh2Oxbk5Djp2ZTA Maaw== Received: by 10.66.78.69 with SMTP id z5mr41985901paw.14.1344521258207; Thu, 09 Aug 2012 07:07:38 -0700 (PDT) Received: from yakj.usersys.redhat.com (93-34-169-1.ip50.fastwebnet.it. [93.34.169.1]) by mx.google.com with ESMTPS id mn9sm1213872pbc.39.2012.08.09.07.07.35 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 09 Aug 2012 07:07:37 -0700 (PDT) From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Thu, 9 Aug 2012 16:07:20 +0200 Message-Id: <1344521241-22897-3-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.7.11.2 In-Reply-To: <1344521241-22897-1-git-send-email-pbonzini@redhat.com> References: <1344521241-22897-1-git-send-email-pbonzini@redhat.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.85.160.173 Cc: kwolf@redhat.com Subject: [Qemu-devel] [PATCH 2/3] virtio-blk: disable write cache if not negotiated X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org If the guest does not support flushes, we should run in writethrough mode. The setting is temporary until the next reset, so that for example the BIOS will run in writethrough mode while Linux will run with a writeback cache. Signed-off-by: Paolo Bonzini --- hw/virtio-blk.c | 14 ++++++++++++++ 1 file modificato, 14 inserzioni(+) diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c index 9c12b61..36bfb12 100644 --- a/hw/virtio-blk.c +++ b/hw/virtio-blk.c @@ -542,6 +542,19 @@ static uint32_t virtio_blk_get_features(VirtIODevice *vdev, uint32_t features) return features; } +static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status) +{ + VirtIOBlock *s = to_virtio_blk(vdev); + uint32_t features; + + if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) { + return; + } + + features = vdev->guest_features; + bdrv_set_enable_write_cache(s->bs, !!(features & (1 << VIRTIO_BLK_F_WCE))); +} + static void virtio_blk_save(QEMUFile *f, void *opaque) { VirtIOBlock *s = opaque; @@ -622,6 +635,7 @@ VirtIODevice *virtio_blk_init(DeviceState *dev, VirtIOBlkConf *blk) s->vdev.get_config = virtio_blk_update_config; s->vdev.set_config = virtio_blk_set_config; s->vdev.get_features = virtio_blk_get_features; + s->vdev.set_status = virtio_blk_set_status; s->vdev.reset = virtio_blk_reset; s->bs = blk->conf.bs; s->conf = &blk->conf;