From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:50500) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SzsNE-0006ZS-Pb for qemu-devel@nongnu.org; Fri, 10 Aug 2012 12:47:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SzsNC-00084m-M8 for qemu-devel@nongnu.org; Fri, 10 Aug 2012 12:47:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:10418) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SzsNC-00084d-7u for qemu-devel@nongnu.org; Fri, 10 Aug 2012 12:47:42 -0400 From: Kevin Wolf Date: Fri, 10 Aug 2012 18:47:24 +0200 Message-Id: <1344617249-6620-7-git-send-email-kwolf@redhat.com> In-Reply-To: <1344617249-6620-1-git-send-email-kwolf@redhat.com> References: <1344617249-6620-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PATCH 06/11] virtio-blk: disable write cache if not negotiated List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: anthony@codemonkey.ws Cc: kwolf@redhat.com, qemu-devel@nongnu.org From: Paolo Bonzini 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 Signed-off-by: Kevin Wolf --- hw/virtio-blk.c | 14 ++++++++++++++ 1 files changed, 14 insertions(+), 0 deletions(-) diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c index 97bb4bd..fd8fa90 100644 --- a/hw/virtio-blk.c +++ b/hw/virtio-blk.c @@ -543,6 +543,19 @@ 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; @@ -623,6 +636,7 @@ 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; -- 1.7.6.5