[PATCH] nvme-pci: fix dma unmapping when using PRPs and not using the IOVA mapping

[Klara Modin]

Hi,

On 2025-07-11 10:32:51 +0200, Christoph Hellwig wrote:
> Hi Klara,
> 
> can you try the attached patch?
> 
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index 6af184f2b73b..ac3b90d31380 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -745,7 +745,7 @@ static bool nvme_pci_prp_iter_next(struct request *req, struct device *dma_dev,
>  		return true;
>  	if (!blk_rq_dma_map_iter_next(req, dma_dev, &iod->dma_state, iter))
>  		return false;
> -	if (dma_need_unmap(dma_dev)) {
> +	if (!dma_use_iova(&iod->dma_state) && dma_need_unmap(dma_dev)) {
>  		iod->dma_vecs[iod->nr_dma_vecs].addr = iter->addr;
>  		iod->dma_vecs[iod->nr_dma_vecs].len = iter->len;
>  		iod->nr_dma_vecs++;
> @@ -763,7 +763,7 @@ static blk_status_t nvme_pci_setup_data_prp(struct request *req,
>  	unsigned int prp_len, i;
>  	__le64 *prp_list;
>  
> -	if (dma_need_unmap(nvmeq->dev->dev)) {
> +	if (!dma_use_iova(&iod->dma_state) && dma_need_unmap(nvmeq->dev->dev)) {
>  		iod->dma_vecs = mempool_alloc(nvmeq->dev->dmavec_mempool,
>  				GFP_ATOMIC);
>  		if (!iod->dma_vecs)

Yes, this fixes it for me.

Thanks,
Tested-by: Klara Modin <klarasmodin at gmail.com>