On Thu, Sep 22, 2016 at 01:23:16PM +0100, Stefan Hajnoczi wrote:
> On Sun, Sep 04, 2016 at 11:38:59PM +0900, Namhyung Kim wrote:
> > +static void virtio_pstore_handle_io(VirtIODevice *vdev, VirtQueue *vq)
> > +{
> > + VirtIOPstore *s = VIRTIO_PSTORE(vdev);
> > + VirtQueueElement *elem;
> > + struct virtio_pstore_req req;
> > + struct virtio_pstore_res res;
> > + ssize_t len = 0;
> > + int ret;
> > +
> > + for (;;) {
> > + elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
> > + if (!elem) {
> > + return;
> > + }
> > +
> > + if (elem->out_num < 1 || elem->in_num < 1) {
> > + error_report("request or response buffer is missing");
> > + exit(1);
>
> The new virtio_error() function might be available, depending on when
> this patch series is merged. virtio_error() should be used instead of
> exit(1). See "[PATCH v5 0/9] virtio: avoid exit() when device enters
> invalid states" on qemu-devel.
Thanks for the info, will take a look.
>
> > + }
> > +
> > + if (elem->out_num > 2 || elem->in_num > 3) {
> > + error_report("invalid number of input/output buffer");
> > + exit(1);
> > + }
>
> The VIRTIO specification requires that flexible framing is supported.
> The device cannot make assumptions about the scatter-gather list. It
> must support any layout (e.g. even multiple 1-byte iovecs making up the
> buffer).
Ok.
>
> > +
> > + len = iov_to_buf(elem->out_sg, elem->out_num, 0, &req,
> > sizeof(req));
> > + if (len != (ssize_t)sizeof(req)) {
> > + error_report("invalid request size: %ld", (long)len);
> > + exit(1);
> > + }
> > + res.cmd = req.cmd;
> > + res.type = req.type;
> > +
> > + switch (le16_to_cpu(req.cmd)) {
> > + case VIRTIO_PSTORE_CMD_OPEN:
> > + ret = virtio_pstore_do_open(s);
> > + break;
> > + case VIRTIO_PSTORE_CMD_CLOSE:
> > + ret = virtio_pstore_do_close(s);
> > + break;
> > + case VIRTIO_PSTORE_CMD_ERASE:
> > + ret = virtio_pstore_do_erase(s, &req);
> > + break;
> > + case VIRTIO_PSTORE_CMD_READ:
> > + ret = virtio_pstore_do_read(s, elem);
> > + if (ret == 1) {
> > + /* async channel io */
> > + continue;
> > + }
> > + break;
> > + case VIRTIO_PSTORE_CMD_WRITE:
> > + ret = virtio_pstore_do_write(s, elem, &req);
> > + if (ret == 1) {
> > + /* async channel io */
> > + continue;
> > + }
> > + break;
> > + default:
> > + ret = -1;
> > + break;
> > + }
> > +
> > + res.ret = ret;
>
> Missing cpu_to_le()?
Right!
>
> > +static void pstore_set_bufsize(Object *obj, Visitor *v,
> > + const char *name, void *opaque,
> > + Error **errp)
> > +{
> > + VirtIOPstore *s = opaque;
> > + Error *error = NULL;
> > + uint64_t value;
> > +
> > + visit_type_size(v, name, &value, &error);
> > + if (error) {
> > + error_propagate(errp, error);
> > + return;
> > + }
> > +
> > + if (value < 4096) {
> > + error_setg(&error, "Warning: too small buffer size: %"PRIu64,
> > value);
>
> This is an error, not a warning. Please remove "Warning:" so it's clear
> to the user that this message caused QEMU to fail.
Will do.
Thanks,
Namhyung
