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authorChangpeng Liu <changpeng.liu@intel.com>2019-02-13 09:48:57 +0800
committerStefan Hajnoczi <stefanha@redhat.com>2019-02-13 16:18:17 +0800
commit42824b4d16da56a50ff4027f6cd22378e0e2666e (patch)
tree5f217380c4dd58da96726af9c82e9ba33eb9b092 /hw/block/virtio-blk.c
parent0b5e750bea635b167eb03d86c3d9a09bbd43bc06 (diff)
virtio-blk: set correct config size for the host driver
Commit caa1ee43 "vhost-user-blk: add discard/write zeroes features support" added fields to struct virtio_blk_config. This changes the size of the config space and breaks migration from QEMU 3.1 and older: qemu-system-ppc64: get_pci_config_device: Bad config data: i=0x10 read: 41 device: 1 cmask: ff wmask: 80 w1cmask:0 qemu-system-ppc64: Failed to load PCIDevice:config qemu-system-ppc64: Failed to load virtio-blk:virtio qemu-system-ppc64: error while loading state for instance 0x0 of device 'pci@800000020000000:01.0/virtio-blk' qemu-system-ppc64: load of migration failed: Invalid argument Since virtio-blk doesn't support the "discard" and "write zeroes" features, it shouldn't even expose the associated fields in the config space actually. Just include all fields up to num_queues to match QEMU 3.1 and older. Signed-off-by: Changpeng Liu <changpeng.liu@intel.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Message-id: 1550022537-27565-1-git-send-email-changpeng.liu@intel.com Message-Id: <1550022537-27565-1-git-send-email-changpeng.liu@intel.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'hw/block/virtio-blk.c')
-rw-r--r--hw/block/virtio-blk.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index 843bb2bec8..cf7f47eaba 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -28,6 +28,10 @@
#include "hw/virtio/virtio-bus.h"
#include "hw/virtio/virtio-access.h"
+/* We don't support discard yet, hide associated config fields. */
+#define VIRTIO_BLK_CFG_SIZE offsetof(struct virtio_blk_config, \
+ max_discard_sectors)
+
static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq,
VirtIOBlockReq *req)
{
@@ -757,7 +761,8 @@ static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config)
blkcfg.alignment_offset = 0;
blkcfg.wce = blk_enable_write_cache(s->blk);
virtio_stw_p(vdev, &blkcfg.num_queues, s->conf.num_queues);
- memcpy(config, &blkcfg, sizeof(struct virtio_blk_config));
+ memcpy(config, &blkcfg, VIRTIO_BLK_CFG_SIZE);
+ QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE > sizeof(blkcfg));
}
static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
@@ -765,7 +770,8 @@ static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
VirtIOBlock *s = VIRTIO_BLK(vdev);
struct virtio_blk_config blkcfg;
- memcpy(&blkcfg, config, sizeof(blkcfg));
+ memcpy(&blkcfg, config, VIRTIO_BLK_CFG_SIZE);
+ QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE > sizeof(blkcfg));
aio_context_acquire(blk_get_aio_context(s->blk));
blk_set_enable_write_cache(s->blk, blkcfg.wce != 0);
@@ -948,8 +954,7 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
return;
}
- virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK,
- sizeof(struct virtio_blk_config));
+ virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, VIRTIO_BLK_CFG_SIZE);
s->blk = conf->conf.blk;
s->rq = NULL;