On 10/21/2019 9:03 AM, [email protected] wrote:
> From: Vamsi Attunuru <[email protected]>
>
> Patch adds support for kernel module to work in
> IOVA = VA mode by providing address translation
> routines to convert IOVA aka user space VA to
> kernel virtual addresses.
>
> Signed-off-by: Vamsi Attunuru <[email protected]>
> Signed-off-by: Kiran Kumar K <[email protected]>
<...>
> +static inline phys_addr_t iova_to_phys(struct task_struct *tsk,
> + unsigned long iova)
> +{
> + unsigned int flags = FOLL_TOUCH;
> + phys_addr_t offset, phys_addr;
> + struct page *page = NULL;
> + int ret;
> +
> + offset = iova & (PAGE_SIZE - 1);
> +
> + /* Read one page struct info */
> + ret = get_user_pages_remote(tsk, tsk->mm, iova, 1,
> + flags, &page, 0, 0);
> + if (ret < 0)
> + return 0;
> +
> + phys_addr = page_to_phys(page) | offset;
> + put_page(page);
> +
> + return phys_addr;
> +}
> +
> +static inline void *iova_to_kva(struct task_struct *tsk, unsigned long iova)
> +{
> + return phys_to_virt(iova_to_phys(tsk, iova));
> +}
Do you have any measurement for the performance affect of this change?
> +
> void kni_net_release_fifo_phy(struct kni_dev *kni);
> void kni_net_rx(struct kni_dev *kni);
> void kni_net_init(struct net_device *dev);
> diff --git a/kernel/linux/kni/kni_misc.c b/kernel/linux/kni/kni_misc.c
> index 2b75502..7af7ab4 100644
> --- a/kernel/linux/kni/kni_misc.c
> +++ b/kernel/linux/kni/kni_misc.c
> @@ -348,15 +348,36 @@ kni_ioctl_create(struct net *net, uint32_t ioctl_num,
> strncpy(kni->name, dev_info.name, RTE_KNI_NAMESIZE);
>
> /* Translate user space info into kernel space info */
> - kni->tx_q = phys_to_virt(dev_info.tx_phys);
> - kni->rx_q = phys_to_virt(dev_info.rx_phys);
> - kni->alloc_q = phys_to_virt(dev_info.alloc_phys);
> - kni->free_q = phys_to_virt(dev_info.free_phys);
> -
> - kni->req_q = phys_to_virt(dev_info.req_phys);
> - kni->resp_q = phys_to_virt(dev_info.resp_phys);
> - kni->sync_va = dev_info.sync_va;
> - kni->sync_kva = phys_to_virt(dev_info.sync_phys);
> + if (dev_info.iova_mode) {
> +#ifdef HAVE_IOVA_TO_KVA_MAPPING_SUPPORT
Do you think is a runtime check required, for the case code has been compiled on
a box that has newer kernel but run in a box with older kernel?
Not sure about it myself either...
<...>
> @@ -62,6 +76,24 @@ kva2data_kva(struct rte_kni_mbuf *m)
> return phys_to_virt(m->buf_physaddr + m->data_off);
> }
>
> +static inline void *
> +get_kva(struct kni_dev *kni, void *pa)
> +{
> + if (kni->iova_mode == 1)
This check done multiple times per packet, I wonder if this can be prevented,
again even with the original mode do you have any numbers related to the
performance affect of this check?
Thanks,
ferruh
