@@ -81,10 +81,11 @@ static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
virtio_scsi_free_req(req);
}
-static void virtio_scsi_bad_req(void)
+static void virtio_scsi_bad_req(VirtIOSCSIReq *req)
{
- error_report("wrong size for virtio-scsi headers");
- exit(1);
+ virtio_error(VIRTIO_DEVICE(req->dev), "wrong size for virtio-scsi headers");
+ virtqueue_detach_element(req->vq, &req->elem, 0);
+ virtio_scsi_free_req(req);
}
static size_t qemu_sgl_concat(VirtIOSCSIReq *req, struct iovec *iov,
@@ -387,7 +388,7 @@ static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
&type, sizeof(type)) < sizeof(type)) {
- virtio_scsi_bad_req();
+ virtio_scsi_bad_req(req);
return;
}
@@ -395,7 +396,8 @@ static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
if (type == VIRTIO_SCSI_T_TMF) {
if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlTMFReq),
sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
- virtio_scsi_bad_req();
+ virtio_scsi_bad_req(req);
+ return;
} else {
r = virtio_scsi_do_tmf(s, req);
}
@@ -404,7 +406,8 @@ static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
type == VIRTIO_SCSI_T_AN_SUBSCRIBE) {
if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICtrlANReq),
sizeof(VirtIOSCSICtrlANResp)) < 0) {
- virtio_scsi_bad_req();
+ virtio_scsi_bad_req(req);
+ return;
} else {
req->resp.an.event_actual = 0;
req->resp.an.response = VIRTIO_SCSI_S_OK;
@@ -521,7 +524,7 @@ static void virtio_scsi_fail_cmd_req(VirtIOSCSIReq *req)
virtio_scsi_complete_cmd_req(req);
}
-static bool virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
+static int virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
{
VirtIOSCSICommon *vs = &s->parent_obj;
SCSIDevice *d;
@@ -532,17 +535,18 @@ static bool virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req
if (rc < 0) {
if (rc == -ENOTSUP) {
virtio_scsi_fail_cmd_req(req);
+ return -ENOTSUP;
} else {
- virtio_scsi_bad_req();
+ virtio_scsi_bad_req(req);
+ return -EINVAL;
}
- return false;
}
d = virtio_scsi_device_find(s, req->req.cmd.lun);
if (!d) {
req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
virtio_scsi_complete_cmd_req(req);
- return false;
+ return -ENOENT;
}
virtio_scsi_ctx_check(s, d);
req->sreq = scsi_req_new(d, req->req.cmd.tag,
@@ -554,11 +558,11 @@ static bool virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req
req->sreq->cmd.xfer > req->qsgl.size)) {
req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
virtio_scsi_complete_cmd_req(req);
- return false;
+ return -ENOBUFS;
}
scsi_req_ref(req->sreq);
blk_io_plug(d->conf.blk);
- return true;
+ return 0;
}
static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
@@ -574,11 +578,24 @@ static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
void virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
{
VirtIOSCSIReq *req, *next;
+ int ret;
+
QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
while ((req = virtio_scsi_pop_req(s, vq))) {
- if (virtio_scsi_handle_cmd_req_prepare(s, req)) {
+ ret = virtio_scsi_handle_cmd_req_prepare(s, req);
+ if (!ret) {
QTAILQ_INSERT_TAIL(&reqs, req, next);
+ } else if (ret == -EINVAL) {
+ /* The device is broken and shouldn't process any request */
+ while (!QTAILQ_EMPTY(&reqs)) {
+ req = QTAILQ_FIRST(&reqs);
+ QTAILQ_REMOVE(&reqs, req, next);
+ blk_io_unplug(req->sreq->dev->conf.blk);
+ scsi_req_unref(req->sreq);
+ virtqueue_detach_element(req->vq, &req->elem, 0);
+ virtio_scsi_free_req(req);
+ }
}
}
@@ -708,7 +725,8 @@ void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
}
if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
- virtio_scsi_bad_req();
+ virtio_scsi_bad_req(req);
+ goto out;
}
evt = &req->resp.event;
The virtio_scsi_bad_req() function is called when a guest sends a request with missing or ill-sized headers. This generally happens when the virtio_scsi_parse_req() function returns an error. With this patch, virtio_scsi_bad_req() will mark the device as broken, detach the request from the virtqueue and free it, instead of forcing QEMU to exit. In nearly all locations where virtio_scsi_bad_req() is called, the only thing to do next is to return to the caller. The virtio_scsi_handle_cmd_req_prepare() function is an exception though. It is called in a loop by virtio_scsi_handle_cmd_vq() and passed requests freshly popped from a cmd virtqueue; virtio_scsi_handle_cmd_req_prepare() does some sanity checks on the request and returns a boolean flag to indicate whether the request should be queued or not. In the latter case, virtio_scsi_handle_cmd_req_prepare() has detected a non-fatal error and sent a response back to the guest. We have now a new condition to take into account: the device is broken and should stop all processing. The return value of virtio_scsi_handle_cmd_req_prepare() is hence changed to an int. A return value of zero means that the request should be queued. Other non-fatal error cases where the request shoudn't be queued return a negative errno (values are vaguely inspired by the error condition, but the only goal here is to discriminate the case we're interested in). And finally, if virtio_scsi_bad_req() was called, -EINVAL is returned. In this case, virtio_scsi_handle_cmd_vq() detaches and frees already queued requests, instead of submitting them. Signed-off-by: Greg Kurz <groug@kaod.org> --- v4: - fixed success return value in virtio_scsi_handle_cmd_req_prepare() - fixed typo in changelog --- hw/scsi/virtio-scsi.c | 46 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 32 insertions(+), 14 deletions(-)