> On Aug 29, 2024, at 16:57, Konrad Sztyber <konrad.szty...@intel.com> wrote:
>
> External email: Use caution opening links or attachments
>
>
> The uio_pci_generic driver clears the bus master bit when the device
> file is closed. So, when the secondary process terminates after probing
> a device, that device becomes unusable in the primary process.
>
> To avoid that, the device file is now opened only in the primary
> process. The commit that introduced this regression, 847d78fb9530
> ("bus/pci: fix FD in secondary process"), only mentioned enabling access
> to config space from secondary process, which still works, as it doesn't
> rely on the device file.
>
> Fixes: 847d78fb9530 ("bus/pci: fix FD in secondary process")
> Cc: sta...@dpdk.org
>
> Signed-off-by: Konrad Sztyber <konrad.szty...@intel.com>
> ---
> drivers/bus/pci/linux/pci_uio.c | 27 +++++++++++++++------------
> 1 file changed, 15 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/bus/pci/linux/pci_uio.c b/drivers/bus/pci/linux/pci_uio.c
> index 4c1d3327a9..5c4ba8098c 100644
> --- a/drivers/bus/pci/linux/pci_uio.c
> +++ b/drivers/bus/pci/linux/pci_uio.c
> @@ -232,18 +232,6 @@ pci_uio_alloc_resource(struct rte_pci_device *dev,
> loc->domain, loc->bus, loc->devid, loc->function);
> return 1;
> }
> - snprintf(devname, sizeof(devname), "/dev/uio%u", uio_num);
> -
> - /* save fd */
> - fd = open(devname, O_RDWR);
> - if (fd < 0) {
> - PCI_LOG(ERR, "Cannot open %s: %s", devname, strerror(errno));
> - goto error;
> - }
> -
> - if (rte_intr_fd_set(dev->intr_handle, fd))
> - goto error;
> -
> snprintf(cfgname, sizeof(cfgname),
> "/sys/class/uio/uio%u/device/config", uio_num);
>
> @@ -273,6 +261,21 @@ pci_uio_alloc_resource(struct rte_pci_device *dev,
> if (rte_eal_process_type() != RTE_PROC_PRIMARY)
> return 0;
>
> + /*
> + * the uio_pci_generic driver clears the bus master enable bit when
> the device file is
> + * closed, so open it only in the primary process
> + */
> + snprintf(devname, sizeof(devname), "/dev/uio%u", uio_num);
> + /* save fd */
> + fd = open(devname, O_RDWR);
> + if (fd < 0) {
> + PCI_LOG(ERR, "Cannot open %s: %s", devname, strerror(errno));
> + goto error;
> + }
> +
> + if (rte_intr_fd_set(dev->intr_handle, fd))
> + goto error;
> +
> /* allocate the mapping details for secondary processes*/
> *uio_res = rte_zmalloc("UIO_RES", sizeof(**uio_res), 0);
> if (*uio_res == NULL) {
> --
> 2.45.0
>
Reviewed-by: Chenbo Xia <chen...@nvidia.com>
