On 8/24/2026 11:35 AM, Mathieu Poirier wrote:
>> + dev_dbg(&vdev->dev,
>> + "vdev config: ver=%u, rx sz = 0x%x, tx sz = 0x%x\n",
>> + version, vrp->rx_buf_size, vrp->tx_buf_size);
>> + } else {
>> + vrp->rx_buf_size = DEFAULT_RPMSG_BUF_SIZE;
>> + vrp->tx_buf_size = DEFAULT_RPMSG_BUF_SIZE;
>> + }
>>
>
> Please move the above to a distinct funtion.
>
> I am done reviewing this set.
>
> Thanks,
> Mathieu
>
Thank You Mathieu.
I started addressing the comments, but missed to ack here. I agree to
all the comments and will be addressed in the next revision.
Tanmay
>> - total_buf_space = (vrp->num_rx_buf + vrp->num_tx_buf) * vrp->buf_size;
>> + total_buf_space = (vrp->num_rx_buf * vrp->rx_buf_size) +
>> + (vrp->num_tx_buf * vrp->tx_buf_size);
>>
>> /* allocate coherent memory for the buffers */
>> bufs_va = dma_alloc_coherent(vdev->dev.parent,
>> @@ -873,15 +925,14 @@ static int rpmsg_probe(struct virtio_device *vdev)
>> /* first part of the buffers is dedicated for RX */
>> vrp->rx_bufs = bufs_va;
>>
>> - /* and second part is dedicated for TX */
>> - vrp->tx_bufs = bufs_va + vrp->num_rx_buf * vrp->buf_size;
>> + vrp->tx_bufs = bufs_va + (vrp->num_rx_buf * vrp->rx_buf_size);
>>
>> /* set up the receive buffers */
>> for (i = 0; i < vrp->num_rx_buf; i++) {
>> struct scatterlist sg;
>> - void *cpu_addr = vrp->rx_bufs + i * vrp->buf_size;
>> + void *cpu_addr = vrp->rx_bufs + i * vrp->rx_buf_size;
>>
>> - rpmsg_sg_init(&sg, cpu_addr, vrp->buf_size);
>> + rpmsg_sg_init(&sg, cpu_addr, vrp->rx_buf_size);
>>
>> err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, cpu_addr,
>> GFP_KERNEL);
>> @@ -964,8 +1015,8 @@ static int rpmsg_remove_device(struct device *dev, void
>> *data)
>> static void rpmsg_remove(struct virtio_device *vdev)
>> {
>> struct virtproc_info *vrp = vdev->priv;
>> - unsigned int num_bufs = vrp->num_rx_buf + vrp->num_tx_buf;
>> - size_t total_buf_space = num_bufs * vrp->buf_size;
>> + size_t total_buf_space = (vrp->num_rx_buf * vrp->rx_buf_size) +
>> + (vrp->num_tx_buf * vrp->tx_buf_size);
>> int ret;
>>
>> virtio_reset_device(vdev);
>> @@ -991,6 +1042,7 @@ static struct virtio_device_id id_table[] = {
>>
>> static unsigned int features[] = {
>> VIRTIO_RPMSG_F_NS,
>> + VIRTIO_RPMSG_F_BUFSZ,
>> };
>>
>> static struct virtio_driver virtio_ipc_driver = {
>> diff --git a/include/linux/rpmsg/virtio_rpmsg.h
>> b/include/linux/rpmsg/virtio_rpmsg.h
>> new file mode 100644
>> index 000000000000..e28144253a12
>> --- /dev/null
>> +++ b/include/linux/rpmsg/virtio_rpmsg.h
>> @@ -0,0 +1,41 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + * Copyright (C) Pinecone Inc. 2019
>> + * Copyright (C) Xiang Xiao <[email protected]>
>> + * Copyright (C) Advanced Micro Devices, Inc. 2026
>> + */
>> +
>> +#ifndef _LINUX_VIRTIO_RPMSG_H
>> +#define _LINUX_VIRTIO_RPMSG_H
>> +
>> +#include <linux/types.h>
>> +#include <linux/virtio_types.h>
>> +
>> +/* The feature bitmap for virtio rpmsg */
>> +#define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */
>> +#define VIRTIO_RPMSG_F_BUFSZ 1 /* RP get buffer size from config
>> space */
>> +
>> +/* Version of struct virtio_rpmsg_config understood by this driver */
>> +#define RPMSG_VDEV_CONFIG_V1 1
>> +
>> +/**
>> + * struct virtio_rpmsg_config - config space for rpmsg virtio device
>> + *
>> + * @version: version of this structure, currently
>> %RPMSG_VDEV_CONFIG_V1.
>> + * @size: size of this structure in bytes.
>> + * @txbuf_size: Tx buf size from remote's view. For Linux this is rx
>> buf size.
>> + * @rxbuf_size: Rx buf size from remote's view. For Linux this is tx
>> buf size.
>> + *
>> + * This is the configuration structure shared by the device and the driver,
>> + * read when %VIRTIO_RPMSG_F_BUFSZ is negotiated. The fields are laid out so
>> + * the structure is naturally 32-bit aligned.
>> + */
>> +struct virtio_rpmsg_config {
>> + u8 version;
>> + __virtio16 size;
>> + /* The tx/rx individual buffer size (if VIRTIO_RPMSG_F_BUFSZ) */
>> + __virtio32 txbuf_size;
>> + __virtio32 rxbuf_size;
>> +} __packed;
>> +
>> +#endif /* _LINUX_VIRTIO_RPMSG_H */
>> --
>> 2.43.0
>>
