[dpdk-dev] [PATCH] vfio: use right index when tracking devices in a vfio group
Burakov, Anatoly
anatoly.burakov at intel.com
Tue May 9 17:18:22 CEST 2017
Hi Alejandro,
> From: Alejandro Lucero [mailto:alejandro.lucero at netronome.com]
> Sent: Monday, May 8, 2017 6:44 PM
> To: dev at dpdk.org
> Cc: Burakov, Anatoly <anatoly.burakov at intel.com>;
> jerin.jacob at caviumnetworks.com; thomas at monjalon.net
> Subject: [PATCH] vfio: use right index when tracking devices in a vfio group
>
> Previous fix for properly handling devices from the same VFIO group
> introduced another bug where the file descriptor of a kernel vfio group is
> used as the index for tracking number of devices of a vfio group struct
> handled by dpdk vfio code. Instead of the file descriptor itself, the vfio group
> object that file descriptor is registered with has to be used.
>
> This patch introduces specific functions for incrementing or decrementing
> the device counter for a specific vfio group using the vfio file descriptor as a
> parameter. Note the code is not optimized as the vfio group is found
> sequentially going through the vfio group array but this should not be a
> problem as this is not related to packet handling at all.
>
> Fixes: a9c349e3a100 ("vfio: fix device unplug when several devices per
> group")
>
> Signed-off-by: Alejandro Lucero <alejandro.lucero at netronome.com>
> ---
> lib/librte_eal/linuxapp/eal/eal_vfio.c | 60
> +++++++++++++++++++++++++++-------
> 1 file changed, 49 insertions(+), 11 deletions(-)
>
> diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio.c
> b/lib/librte_eal/linuxapp/eal/eal_vfio.c
> index d3eae20..21d126f 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_vfio.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_vfio.c
> @@ -172,6 +172,44 @@
> return -1;
> }
>
> +
> +static int
> +get_vfio_group_idx(int vfio_group_fd)
> +{
> + int i;
> + for (i = 0; i < VFIO_MAX_GROUPS; i++)
> + if (vfio_cfg.vfio_groups[i].fd == vfio_group_fd)
> + return i;
> + return -1;
> +}
> +
> +static void
> +vfio_group_device_get(int vfio_group_fd) {
> + int i;
> +
> + i = get_vfio_group_idx(vfio_group_fd);
> + vfio_cfg.vfio_groups[i].devices++;
Maybe add a check for I < 0?
> +}
> +
> +static void
> +vfio_group_device_put(int vfio_group_fd) {
> + int i;
> +
> + i = get_vfio_group_idx(vfio_group_fd);
> + vfio_cfg.vfio_groups[i].devices--;
Same here.
> +}
> +
> +static int
> +vfio_group_device_count(int vfio_group_fd) {
> + int i;
> +
> + i = get_vfio_group_idx(vfio_group_fd);
> + return vfio_cfg.vfio_groups[i].devices; }
And here.
> +
> int
> clear_group(int vfio_group_fd)
> {
> @@ -180,15 +218,14 @@
>
> if (internal_config.process_type == RTE_PROC_PRIMARY) {
>
> - for (i = 0; i < VFIO_MAX_GROUPS; i++)
> - if (vfio_cfg.vfio_groups[i].fd == vfio_group_fd) {
> - vfio_cfg.vfio_groups[i].group_no = -1;
> - vfio_cfg.vfio_groups[i].fd = -1;
> - vfio_cfg.vfio_groups[i].devices = 0;
> - vfio_cfg.vfio_active_groups--;
> - return 0;
> - }
> - return -1;
> + i = get_vfio_group_idx(vfio_group_fd);
> + if ( i < 0)
> + return -1;
> + vfio_cfg.vfio_groups[i].group_no = -1;
> + vfio_cfg.vfio_groups[i].fd = -1;
> + vfio_cfg.vfio_groups[i].devices = 0;
> + vfio_cfg.vfio_active_groups--;
> + return 0;
> }
>
> /* This is just for SECONDARY processes */ @@ -358,7 +395,7 @@
> clear_group(vfio_group_fd);
> return -1;
> }
> - vfio_cfg.vfio_groups[vfio_group_fd].devices++;
> + vfio_group_device_get(vfio_group_fd);
>
> return 0;
> }
> @@ -406,7 +443,8 @@
> /* An VFIO group can have several devices attached. Just when there
> is
> * no devices remaining should the group be closed.
> */
> - if (--vfio_cfg.vfio_groups[vfio_group_fd].devices == 0) {
> + vfio_group_device_put(vfio_group_fd);
> + if (!vfio_group_device_count(vfio_group_fd)) {
>
> if (close(vfio_group_fd) < 0) {
> RTE_LOG(INFO, EAL, "Error when closing
> vfio_group_fd for %s\n",
> --
> 1.9.1
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