Re: [Qemu-devel] [PULL 40/96] virtio-scsi: use standard-headers

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Mar 11, 2015 at 10:48:27AM +0100, Paolo Bonzini wrote:
> 
> 
> On 11/03/2015 09:31, Michael S. Tsirkin wrote:
> > On Wed, Mar 11, 2015 at 03:14:16PM +0800, Fam Zheng wrote:
> >> On Wed, 02/18 22:48, Michael S. Tsirkin wrote:
> >>> Drop duplicated code.
> >>>
> >>> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> >>> Acked-by: Paolo Bonzini <pbonzini@redhat.com>
> >>
> >> Michael, this breaks virtio-scsi-pci:
> >>
> >>     qemu-system-x86_64: wrong size for virtio-scsi headers
> > 
> > Testing this now.
> > 
> > diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h
> > index de2c739..25d96f3 100644
> > --- a/include/hw/virtio/virtio-scsi.h
> > +++ b/include/hw/virtio/virtio-scsi.h
> > @@ -136,15 +136,15 @@ typedef struct VirtIOSCSIReq {
> >      union {
> >          struct {
> >              VirtIOSCSICmdReq  cmd;
> > -            uint8_t           cdb[];
> >          } QEMU_PACKED;
> >          VirtIOSCSICtrlTMFReq  tmf;
> >          VirtIOSCSICtrlANReq   an;
> >      } req;
> >  } VirtIOSCSIReq;
> >  
> > -QEMU_BUILD_BUG_ON(offsetof(VirtIOSCSIReq, req.cdb) !=
> > -                  offsetof(VirtIOSCSIReq, req.cmd) + sizeof(VirtIOSCSICmdReq));
> > +QEMU_BUILD_BUG_ON(offsetof(VirtIOSCSIReq, req.cmd.cdb) !=
> > +                  offsetof(VirtIOSCSIReq, req.cmd) +
> > +                  offsetof(VirtIOSCSICmdReq, cdb));
> 
> No, this is too ugly.  Can I just queue a revert?
> 
> Paolo

How about we just drop this chunk? It's not checking anything useful
now.
Others are good?


> >  #define DEFINE_VIRTIO_SCSI_PROPERTIES(_state, _conf_field)                     \
> >      DEFINE_PROP_UINT32("num_queues", _state, _conf_field.num_queues, 1),       \
> > diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
> > index cfb52e8..52bc00c 100644
> > --- a/hw/scsi/virtio-scsi.c
> > +++ b/hw/scsi/virtio-scsi.c
> > @@ -47,7 +47,8 @@ VirtIOSCSIReq *virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq)
> >      const size_t zero_skip = offsetof(VirtIOSCSIReq, elem)
> >                               + sizeof(VirtQueueElement);
> >  
> > -    req = g_slice_alloc(sizeof(*req) + vs->cdb_size);
> > +    req = g_slice_alloc(sizeof(*req) + MAX(vs->cdb_size, VIRTIO_SCSI_CDB_SIZE) -
> > +                        VIRTIO_SCSI_CDB_SIZE);
> >      req->vq = vq;
> >      req->dev = s;
> >      qemu_sglist_init(&req->qsgl, DEVICE(s), 8, &address_space_memory);
> > @@ -62,7 +63,8 @@ void virtio_scsi_free_req(VirtIOSCSIReq *req)
> >  
> >      qemu_iovec_destroy(&req->resp_iov);
> >      qemu_sglist_destroy(&req->qsgl);
> > -    g_slice_free1(sizeof(*req) + vs->cdb_size, req);
> > +    g_slice_free1(sizeof(*req) + MAX(vs->cdb_size, VIRTIO_SCSI_CDB_SIZE) -
> > +                        VIRTIO_SCSI_CDB_SIZE, req);
> >  }
> >  
> >  static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
> > @@ -213,8 +215,10 @@ static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
> >      assert(req->elem.in_num <= ARRAY_SIZE(req->elem.in_sg));
> >      assert(req->elem.out_num <= ARRAY_SIZE(req->elem.out_sg));
> >  
> > -    if (virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
> > -                              sizeof(VirtIOSCSICmdResp) + vs->sense_size) < 0) {
> > +    if (virtio_scsi_parse_req(req, offsetof(VirtIOSCSICmdReq, cdb) +
> > +                              vs->cdb_size,
> > +                              offsetof(VirtIOSCSICmdResp, sense) +
> > +                              vs->sense_size) < 0) {
> >          error_report("invalid SCSI request migration data");
> >          exit(1);
> >      }
> > @@ -439,7 +443,7 @@ static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
> >      /* Sense data is not in req->resp and is copied separately
> >       * in virtio_scsi_command_complete.
> >       */
> > -    req->resp_size = sizeof(VirtIOSCSICmdResp);
> > +    req->resp_size = offsetof(VirtIOSCSICmdResp, sense);
> >      virtio_scsi_complete_req(req);
> >  }
> >  
> > @@ -462,8 +466,10 @@ static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
> >      } else {
> >          req->resp.cmd.resid = 0;
> >          sense_len = scsi_req_get_sense(r, sense, sizeof(sense));
> > -        sense_len = MIN(sense_len, req->resp_iov.size - sizeof(req->resp.cmd));
> > -        qemu_iovec_from_buf(&req->resp_iov, sizeof(req->resp.cmd),
> > +        sense_len = MIN(sense_len, req->resp_iov.size -
> > +                        offsetof(typeof(req->resp.cmd), sense));
> > +        qemu_iovec_from_buf(&req->resp_iov,
> > +                            offsetof(typeof(req->resp.cmd), sense),
> >                              sense, sense_len);
> >          req->resp.cmd.sense_len = virtio_tswap32(vdev, sense_len);
> >      }
> > @@ -522,8 +528,10 @@ bool virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
> >      SCSIDevice *d;
> >      int rc;
> >  
> > -    rc = virtio_scsi_parse_req(req, sizeof(VirtIOSCSICmdReq) + vs->cdb_size,
> > -                               sizeof(VirtIOSCSICmdResp) + vs->sense_size);
> > +    rc = virtio_scsi_parse_req(req, offsetof(VirtIOSCSICmdReq, cdb) +
> > +                               vs->cdb_size,
> > +                               offsetof(VirtIOSCSICmdResp, sense) +
> > +                               vs->sense_size);
> >      if (rc < 0) {
> >          if (rc == -ENOTSUP) {
> >              virtio_scsi_fail_cmd_req(req);
> > @@ -544,7 +552,7 @@ bool virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
> >      }
> >      req->sreq = scsi_req_new(d, req->req.cmd.tag,
> >                               virtio_scsi_get_lun(req->req.cmd.lun),
> > -                             req->req.cdb, req);
> > +                             req->req.cmd.cdb, req);
> >  
> >      if (req->sreq->cmd.mode != SCSI_XFER_NONE
> >          && (req->sreq->cmd.mode != req->mode ||
> > 
> >