From mboxrd@z Thu Jan 1 00:00:00 1970 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) Sender: Paolo Bonzini From: Paolo Bonzini Date: Thu, 9 Aug 2012 16:07:20 +0200 Message-Id: <1344521241-22897-3-git-send-email-pbonzini@redhat.com> In-Reply-To: <1344521241-22897-1-git-send-email-pbonzini@redhat.com> References: <1344521241-22897-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH 2/3] virtio-blk: disable write cache if not negotiated List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com 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; -- 1.7.11.2