From: Andrea Parri <parri.andrea@gmail.com>
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: linux-kernel@vger.kernel.org,
"K . Y . Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Stephen Hemminger <sthemmin@microsoft.com>,
Wei Liu <wei.liu@kernel.org>,
linux-hyperv@vger.kernel.org,
Michael Kelley <mikelley@microsoft.com>,
Dexuan Cui <decui@microsoft.com>,
Boqun Feng <boqun.feng@gmail.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
"David S. Miller" <davem@davemloft.net>,
netdev@vger.kernel.org
Subject: Re: [RFC PATCH 04/11] hv_netvsc: Disable NAPI before closing the VMBus channel
Date: Thu, 26 Mar 2020 18:55:31 +0100 [thread overview]
Message-ID: <20200326175531.GA20523@andrea> (raw)
In-Reply-To: <20200326082636.1d777921@hermes.lan>
On Thu, Mar 26, 2020 at 08:26:36AM -0700, Stephen Hemminger wrote:
> On Wed, 25 Mar 2020 23:54:58 +0100
> "Andrea Parri (Microsoft)" <parri.andrea@gmail.com> wrote:
>
> > vmbus_chan_sched() might call the netvsc driver callback function that
> > ends up scheduling NAPI work. This "work" can access the channel ring
> > buffer, so we must ensure that any such work is completed and that the
> > ring buffer is no longer being accessed before freeing the ring buffer
> > data structure in the channel closure path. To this end, disable NAPI
> > before calling vmbus_close() in netvsc_device_remove().
> >
> > Suggested-by: Michael Kelley <mikelley@microsoft.com>
> > Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
> > Cc: "David S. Miller" <davem@davemloft.net>
> > Cc: <netdev@vger.kernel.org>
>
> Do you have a test that reproduces this issue?
I don't (or I'm not aware of such a test).
>
> The netvsc device is somewhat unique in that it needs NAPI
> enabled on the primary channel to interact with the host.
> Therefore it can't call napi_disable in the normal dev->stop() place.
>
> Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Thanks!
Andrea
next prev parent reply other threads:[~2020-03-26 17:55 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-25 22:54 [RFC PATCH 00/11] VMBus channel interrupt reassignment Andrea Parri (Microsoft)
2020-03-25 22:54 ` [RFC PATCH 01/11] Drivers: hv: vmbus: Always handle the VMBus messages on CPU0 Andrea Parri (Microsoft)
2020-03-26 14:05 ` Vitaly Kuznetsov
2020-03-28 18:50 ` Andrea Parri
2020-03-25 22:54 ` [RFC PATCH 02/11] Drivers: hv: vmbus: Don't bind the offer&rescind works to a specific CPU Andrea Parri (Microsoft)
2020-03-26 14:16 ` Vitaly Kuznetsov
2020-03-26 15:47 ` Andrea Parri
2020-03-26 17:26 ` Vitaly Kuznetsov
2020-03-28 17:08 ` Andrea Parri
2020-03-29 3:43 ` Michael Kelley
2020-03-30 12:24 ` Vitaly Kuznetsov
2020-04-03 12:04 ` Andrea Parri
2020-03-25 22:54 ` [RFC PATCH 03/11] Drivers: hv: vmbus: Replace the per-CPU channel lists with a global array of channels Andrea Parri (Microsoft)
2020-03-26 14:31 ` Vitaly Kuznetsov
2020-03-26 17:05 ` Andrea Parri
2020-03-26 17:43 ` Vitaly Kuznetsov
2020-03-28 18:21 ` Andrea Parri
2020-03-29 3:49 ` Michael Kelley
2020-03-30 12:45 ` Vitaly Kuznetsov
2020-04-03 13:38 ` Andrea Parri
2020-04-03 14:56 ` Vitaly Kuznetsov
2020-03-25 22:54 ` [RFC PATCH 04/11] hv_netvsc: Disable NAPI before closing the VMBus channel Andrea Parri (Microsoft)
2020-03-26 15:26 ` Stephen Hemminger
2020-03-26 17:55 ` Andrea Parri [this message]
2020-03-25 22:54 ` [RFC PATCH 05/11] hv_utils: Always execute the fcopy and vss callbacks in a tasklet Andrea Parri (Microsoft)
2020-03-25 22:55 ` [RFC PATCH 06/11] Drivers: hv: vmbus: Use a spin lock for synchronizing channel scheduling vs. channel removal Andrea Parri (Microsoft)
2020-03-25 22:55 ` [RFC PATCH 07/11] PCI: hv: Prepare hv_compose_msi_msg() for the VMBus-channel-interrupt-to-vCPU reassignment functionality Andrea Parri (Microsoft)
2020-03-25 22:55 ` [RFC PATCH 08/11] Drivers: hv: vmbus: Remove the unused HV_LOCALIZED channel affinity logic Andrea Parri (Microsoft)
2020-03-25 22:55 ` [RFC PATCH 09/11] Drivers: hv: vmbus: Synchronize init_vp_index() vs. CPU hotplug Andrea Parri (Microsoft)
2020-03-25 22:55 ` [RFC PATCH 10/11] Drivers: hv: vmbus: Introduce the CHANNELMSG_MODIFYCHANNEL message type Andrea Parri (Microsoft)
2020-03-26 14:46 ` Vitaly Kuznetsov
2020-03-28 18:48 ` Andrea Parri
2020-04-03 14:55 ` Andrea Parri
2020-03-25 22:55 ` [RFC PATCH 11/11] scsi: storvsc: Re-init stor_chns when a channel interrupt is re-assigned Andrea Parri (Microsoft)
2020-03-30 16:42 ` Michael Kelley
2020-03-30 18:55 ` Andrea Parri
2020-03-30 19:49 ` Michael Kelley
2020-04-03 13:41 ` Andrea Parri
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