Linux-HyperV Archive on lore.kernel.org
 help / color / Atom feed
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
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

  reply index

Thread overview: 33+ 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
2020-03-25 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
2020-03-25 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
2020-03-25 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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200326175531.GA20523@andrea \
    --to=parri.andrea@gmail.com \
    --cc=boqun.feng@gmail.com \
    --cc=davem@davemloft.net \
    --cc=decui@microsoft.com \
    --cc=haiyangz@microsoft.com \
    --cc=kys@microsoft.com \
    --cc=linux-hyperv@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mikelley@microsoft.com \
    --cc=netdev@vger.kernel.org \
    --cc=stephen@networkplumber.org \
    --cc=sthemmin@microsoft.com \
    --cc=vkuznets@redhat.com \
    --cc=wei.liu@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-HyperV Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-hyperv/0 linux-hyperv/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-hyperv linux-hyperv/ https://lore.kernel.org/linux-hyperv \
		linux-hyperv@vger.kernel.org
	public-inbox-index linux-hyperv

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-hyperv


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git