From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:32994) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wk2Oj-0000nw-59 for qemu-devel@nongnu.org; Mon, 12 May 2014 22:24:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Wk2Oc-0008Nj-TT for qemu-devel@nongnu.org; Mon, 12 May 2014 22:24:53 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42059) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wk2Oc-0008NT-Lx for qemu-devel@nongnu.org; Mon, 12 May 2014 22:24:46 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s4D2Ojos021693 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Mon, 12 May 2014 22:24:45 -0400 From: Fam Zheng Date: Tue, 13 May 2014 10:24:53 +0800 Message-Id: <1399947893-25843-1-git-send-email-famz@redhat.com> Subject: [Qemu-devel] [PATCH] virtio-blk: Allow config-wce in dataplane List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Stefan Hajnoczi Dataplane now uses block layer. Protect bdrv_set_enable_write_cache with aio_context_acquire and aio_context_release, so we can enable config-wce to allow guest to modify the write cache online. Signed-off-by: Fam Zheng --- This applies on top of Stefan's "dataplane: use QEMU block layer" series. Signed-off-by: Fam Zheng --- hw/block/dataplane/virtio-blk.c | 6 ------ hw/block/virtio-blk.c | 9 ++++++++- 2 files changed, 8 insertions(+), 7 deletions(-) diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c index 79fb612..46a6824 100644 --- a/hw/block/dataplane/virtio-blk.c +++ b/hw/block/dataplane/virtio-blk.c @@ -332,12 +332,6 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk, return; } - if (blk->config_wce) { - error_setg(errp, "device is incompatible with x-data-plane, " - "use config-wce=off"); - return; - } - /* If dataplane is (re-)enabled while the guest is running there could be * block jobs that can conflict. */ diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 8a568e5..a031e56 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -26,6 +26,7 @@ # include #endif #include "hw/virtio/virtio-bus.h" +#include "block/block_int.h" typedef struct VirtIOBlockReq { @@ -523,7 +524,10 @@ static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config) struct virtio_blk_config blkcfg; memcpy(&blkcfg, config, sizeof(blkcfg)); + + aio_context_acquire(bdrv_get_aio_context(s->bs)); bdrv_set_enable_write_cache(s->bs, blkcfg.wce != 0); + aio_context_release(bdrv_get_aio_context(s->bs)); } static uint32_t virtio_blk_get_features(VirtIODevice *vdev, uint32_t features) @@ -582,7 +586,10 @@ static void virtio_blk_set_status(VirtIODevice *vdev, uint8_t status) * s->bs would erroneously be placed in writethrough mode. */ if (!(features & (1 << VIRTIO_BLK_F_CONFIG_WCE))) { - bdrv_set_enable_write_cache(s->bs, !!(features & (1 << VIRTIO_BLK_F_WCE))); + aio_context_acquire(bdrv_get_aio_context(s->bs)); + bdrv_set_enable_write_cache(s->bs, + !!(features & (1 << VIRTIO_BLK_F_WCE))); + aio_context_release(bdrv_get_aio_context(s->bs)); } } -- 1.9.2