diff options
author | Greg Kurz <groug@kaod.org> | 2016-09-30 17:13:40 +0200 |
---|---|---|
committer | Michael S. Tsirkin <mst@redhat.com> | 2016-10-10 01:16:59 +0300 |
commit | 661e32fb3cb71c7e019daee375be4bb487b9917c (patch) | |
tree | e00ea43331ff735a64885be68c946575eff3674b | |
parent | fa5e56c2a73501427203c34d702fccc2fbcb5eab (diff) | |
download | qemu-661e32fb3cb71c7e019daee375be4bb487b9917c.zip qemu-661e32fb3cb71c7e019daee375be4bb487b9917c.tar.gz qemu-661e32fb3cb71c7e019daee375be4bb487b9917c.tar.bz2 |
virtio-scsi: convert virtio_scsi_bad_req() to use virtio_error()
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>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
-rw-r--r-- | hw/scsi/virtio-scsi.c | 46 |
1 files changed, 32 insertions, 14 deletions
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c index e596b64..b58de95 100644 --- a/hw/scsi/virtio-scsi.c +++ b/hw/scsi/virtio-scsi.c @@ -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; |