On 09/13, Wang, Xiao W wrote:
>Hi Xiaolong,
>
>> -----Original Message-----
>> From: Ye, Xiaolong
>> Sent: Thursday, September 13, 2018 8:55 PM
>> To: Wang, Xiao W <xiao.w.w...@intel.com>
>> Cc: Bie, Tiwei <tiwei....@intel.com>; dev@dpdk.org
>> Subject: Re: [PATCH] net/ifc: do not notify before HW ready
>>
>> Hi, Xiao
>>
>> On 09/10, Xiao Wang wrote:
>> >Fixes: a3f8150eac6d ("net/ifcvf: add ifcvf vDPA driver")
>>
>> Could you help describe what problem is without this fix in commit log?
>
>Generally a driver should finish all the device configurations first then
>notify the HW for data processing.
>Without this fix, the potential problems are:
>1. If the device is not clearly reset by the previous driver and holds some
>invalid ring addr, and the vDPA relay thread kicks it, a bad DMA request may
>happen.
>2. The notify_addr which is used by the relay thread is set in the
>vdpa_ifcvf_start function. If there's really a kick relay before
>vdpa_ifcvf_start finishes, a null addr is accessed.
>
Thanks for the explanation.
Thanks,
Xiaolong
>Would add the description in the commit log in v2.
>
>Thanks for the comment,
>Xiao
>>
>> Thanks,
>> Xiaolong
>> >
>> >Signed-off-by: Xiao Wang <xiao.w.w...@intel.com>
>> >---
>> > drivers/net/ifc/ifcvf_vdpa.c | 8 ++++----
>> > 1 file changed, 4 insertions(+), 4 deletions(-)
>> >
>> >diff --git a/drivers/net/ifc/ifcvf_vdpa.c b/drivers/net/ifc/ifcvf_vdpa.c
>> >index 3c5430dc0..7d3085d8d 100644
>> >--- a/drivers/net/ifc/ifcvf_vdpa.c
>> >+++ b/drivers/net/ifc/ifcvf_vdpa.c
>> >@@ -503,11 +503,11 @@ update_datapath(struct ifcvf_internal *internal)
>> > if (ret)
>> > goto err;
>> >
>> >- ret = setup_notify_relay(internal);
>> >+ ret = vdpa_ifcvf_start(internal);
>> > if (ret)
>> > goto err;
>> >
>> >- ret = vdpa_ifcvf_start(internal);
>> >+ ret = setup_notify_relay(internal);
>> > if (ret)
>> > goto err;
>> >
>> >@@ -515,12 +515,12 @@ update_datapath(struct ifcvf_internal *internal)
>> > } else if (rte_atomic32_read(&internal->running) &&
>> > (!rte_atomic32_read(&internal->started) ||
>> > !rte_atomic32_read(&internal->dev_attached))) {
>> >- vdpa_ifcvf_stop(internal);
>> >-
>> > ret = unset_notify_relay(internal);
>> > if (ret)
>> > goto err;
>> >
>> >+ vdpa_ifcvf_stop(internal);
>> >+
>> > ret = vdpa_disable_vfio_intr(internal);
>> > if (ret)
>> > goto err;
>> >--
>> >2.15.1
>> >
