On 25-03-21, 17:16, Arnd Bergmann wrote:
On Wed, Mar 24, 2021 at 8:33 AM Viresh Kumar viresh.kumar@linaro.org wrote:
+static void vi2c_handle_ctrl(VuDev *dev, int qidx) +{
- VuVirtq *vq = vu_get_queue(dev, qidx);
- struct i2c_msg msg;
- struct virtio_i2c_out_hdr *out_hdr;
- struct virtio_i2c_in_hdr *in_hdr;
- bool fail_next = false;
- size_t len, in_hdr_len;
- for (;;) {
VuVirtqElement *elem;elem = vu_queue_pop(dev, vq, sizeof(VuVirtqElement));if (!elem) {break;}g_debug("%s: got queue (in %d, out %d)", __func__, elem->in_num,elem->out_num);/* Validate size of out header */if (elem->out_sg[0].iov_len != sizeof(*out_hdr)) {g_warning("%s: Invalid out hdr %zu : %zu\n", __func__,elem->out_sg[0].iov_len, sizeof(*out_hdr));continue;}out_hdr = elem->out_sg[0].iov_base;/* Bit 0 is reserved in virtio spec */msg.addr = out_hdr->addr >> 1;/* Read Operation */if (elem->out_num == 1 && elem->in_num == 2) {len = elem->in_sg[0].iov_len;if (!len) {g_warning("%s: Read buffer length can't be zero\n", __func__);continue;}It looks like you are not handling endianness conversion here. As far as I can tell, the protocol requires little-endian data, but the code might run on a big-endian CPU.
I hope this is all we are required to do here, right ?
@@ -442,7 +421,7 @@ static void vi2c_handle_ctrl(VuDev *dev, int qidx) out_hdr = elem->out_sg[0].iov_base;
/* Bit 0 is reserved in virtio spec */ - msg.addr = out_hdr->addr >> 1; + msg.addr = le16toh(out_hdr->addr) >> 1;
/* Read Operation */ if (elem->out_num == 1 && elem->in_num == 2) { @@ -489,7 +468,7 @@ static void vi2c_handle_ctrl(VuDev *dev, int qidx) in_hdr->status = fail_next ? VIRTIO_I2C_MSG_ERR : vi2c_xfer(dev, &msg); if (in_hdr->status == VIRTIO_I2C_MSG_ERR) { /* We need to fail remaining transfers as well */ - fail_next = out_hdr->flags & VIRTIO_I2C_FLAGS_FAIL_NEXT; + fail_next = le32toh(out_hdr->flags) & VIRTIO_I2C_FLAGS_FAIL_NEXT; }
These are the only fields we are passing apart from buf, which goes directly to the client device.