[PATCH] vmbus: fix missing signaling in hv_signal_on_read()

[PATCH] vmbus: fix missing signaling in hv_signal_on_read()

[Stephen Hemminger]

When the space available before start of reading (cached_write_sz)
is the same as the host required space (pending_sz), we need to
still signal host.

Fixes: 433e19cf33d3 ("Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()")

Signed-off-by: John Starks <jon.Starks@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
---
This patch is for 4.13 (and stable).
A different fix is needed for linux-next.

 include/linux/hyperv.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index e09fc8290c2f..080a0797c6f3 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1515,11 +1515,11 @@ static inline  void hv_signal_on_read(struct vmbus_channel *channel)
 
 	cur_write_sz = hv_get_bytes_to_write(rbi);
 
-	if (cur_write_sz < pending_sz)
+	if (cur_write_sz <= pending_sz)
 		return;
 
 	cached_write_sz = hv_get_cached_bytes_to_write(rbi);
-	if (cached_write_sz < pending_sz)
+	if (cached_write_sz <= pending_sz)
 		vmbus_setevent(channel);
 }
 
-- 
2.11.0

Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()

[Greg KH]

On Wed, Aug 16, 2017 at 08:49:46AM -0700, Stephen Hemminger wrote:
> When the space available before start of reading (cached_write_sz)
> is the same as the host required space (pending_sz), we need to
> still signal host.
> 
> Fixes: 433e19cf33d3 ("Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()")
> 
> Signed-off-by: John Starks <jon.Starks@microsoft.com>
> Signed-off-by: Dexuan Cui <decui@microsoft.com>
> Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
> ---
> This patch is for 4.13 (and stable).
> A different fix is needed for linux-next.

Is there a fix for this in Linus's tree?  If so, what's the git commit
id?  We need to wait for that until I can take it in -stable.

thanks,

greg k-h

Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()

[Stephen Hemminger]

On Wed, 16 Aug 2017 09:10:40 -0700
Greg KH <gregkh@linuxfoundation.org> wrote:

> On Wed, Aug 16, 2017 at 08:49:46AM -0700, Stephen Hemminger wrote:
> > When the space available before start of reading (cached_write_sz)
> > is the same as the host required space (pending_sz), we need to
> > still signal host.
> > 
> > Fixes: 433e19cf33d3 ("Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()")
> > 
> > Signed-off-by: John Starks <jon.Starks@microsoft.com>
> > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
> > ---
> > This patch is for 4.13 (and stable).
> > A different fix is needed for linux-next.  
> 
> Is there a fix for this in Linus's tree?  If so, what's the git commit
> id?  We need to wait for that until I can take it in -stable.

There is no commit yet in Linus's tree. Was submitting for both Linus
and stable. Wasn't sure about the timing since 4.13 might close before he gets to it.

RE: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()

[Dexuan Cui]

> From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> Sent: Wednesday, August 16, 2017 9:16 AM
> To: Greg KH <gregkh@linuxfoundation.org>
> Cc: KY Srinivasan <kys@microsoft.com>; Dexuan Cui <decui@microsoft.com>;
> devel@linuxdriverproject.org; linux-kernel@vger.kernel.org;
> stable@vger.kernel.org; Stephen Hemminger <sthemmin@microsoft.com>;
> John Starks <jon.Starks@microsoft.com>
> Subject: Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()
> 
> On Wed, 16 Aug 2017 09:10:40 -0700
> Greg KH <gregkh@linuxfoundation.org> wrote:
> 
> > On Wed, Aug 16, 2017 at 08:49:46AM -0700, Stephen Hemminger wrote:
> > > When the space available before start of reading (cached_write_sz)
> > > is the same as the host required space (pending_sz), we need to
> > > still signal host.
> > >
> > > Fixes: 433e19cf33d3 ("Drivers: hv: vmbus: finally fix
> hv_need_to_signal_on_read()")
> > >
> > > Signed-off-by: John Starks <jon.Starks@microsoft.com>
> > > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > > Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
> > > ---
> > > This patch is for 4.13 (and stable).
> > > A different fix is needed for linux-next.
> >
> > Is there a fix for this in Linus's tree?  If so, what's the git commit
> > id?  We need to wait for that until I can take it in -stable.
> 
> There is no commit yet in Linus's tree. Was submitting for both Linus
> and stable. Wasn't sure about the timing since 4.13 might close before he gets
> to it.

Hi Greg and stable@vger.kernel.org,
We need the patch for the stable kernels:  v4.13, v4.12.10 and v4.9.47.

The patch is not in Linus's tree, because the bug is resolved there by a series
 of 4 patches (see the below).

IMO it's better to apply this small patch to the stable kernels rather than 
backporting the 4 big commits?

commit 4226ff69a3dff78bead7d9a270423cd21f8d40b8
Author: Stephen Hemminger <stephen@networkplumber.org>
Date:   Sun Jun 25 12:30:24 2017 -0700

    vmbus: simplify hv_ringbuffer_read

    With new iterator functions (and the double mapping) the ring buffer
    read function can be greatly simplified.

    Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
    Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 8dd45f2ab005a1f3301296059b23b03ec3dbf79b
Author: Stephen Hemminger <stephen@networkplumber.org>
Date:   Sun Jun 25 12:30:26 2017 -0700

    vmbus: refactor hv_signal_on_read

    The function hv_signal_on_read was defined in hyperv.h and
    only used in one place in ring_buffer code. Clearer to just
    move it inline there.

    Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
    Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 05d00bc94ac27d220d8a78e365d7fa3a26dcca17
Author: Stephen Hemminger <stephen@networkplumber.org>
Date:   Sun Jun 25 12:30:27 2017 -0700

    vmbus: eliminate duplicate cached index

    Don't need cached read index anymore now that packet iterator
    is used. The iterator has the original read index until the
    visible read_index is updated.

    Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
    Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


commit 03bad714a1619c0074eb44d6f217c505fe27030f
Author: Stephen Hemminger <stephen@networkplumber.org>
Date:   Sun Jun 25 12:30:28 2017 -0700

    vmbus: more host signalling avoidance

    Don't signal host if it has disabled interrupts for that
    ring buffer. Check the feature bit to see if host supports
    pending send size flag.

    Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
    Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Thanks,
-- Dexuan

Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()

[Greg KH]

On Thu, Sep 07, 2017 at 12:54:09AM +0000, Dexuan Cui wrote:
> > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > Sent: Wednesday, August 16, 2017 9:16 AM
> > To: Greg KH <gregkh@linuxfoundation.org>
> > Cc: KY Srinivasan <kys@microsoft.com>; Dexuan Cui <decui@microsoft.com>;
> > devel@linuxdriverproject.org; linux-kernel@vger.kernel.org;
> > stable@vger.kernel.org; Stephen Hemminger <sthemmin@microsoft.com>;
> > John Starks <jon.Starks@microsoft.com>
> > Subject: Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()
> > 
> > On Wed, 16 Aug 2017 09:10:40 -0700
> > Greg KH <gregkh@linuxfoundation.org> wrote:
> > 
> > > On Wed, Aug 16, 2017 at 08:49:46AM -0700, Stephen Hemminger wrote:
> > > > When the space available before start of reading (cached_write_sz)
> > > > is the same as the host required space (pending_sz), we need to
> > > > still signal host.
> > > >
> > > > Fixes: 433e19cf33d3 ("Drivers: hv: vmbus: finally fix
> > hv_need_to_signal_on_read()")
> > > >
> > > > Signed-off-by: John Starks <jon.Starks@microsoft.com>
> > > > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > > > Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
> > > > ---
> > > > This patch is for 4.13 (and stable).
> > > > A different fix is needed for linux-next.
> > >
> > > Is there a fix for this in Linus's tree?  If so, what's the git commit
> > > id?  We need to wait for that until I can take it in -stable.
> > 
> > There is no commit yet in Linus's tree. Was submitting for both Linus
> > and stable. Wasn't sure about the timing since 4.13 might close before he gets
> > to it.
> 
> Hi Greg and stable@vger.kernel.org,
> We need the patch for the stable kernels:  v4.13, v4.12.10 and v4.9.47.
> 
> The patch is not in Linus's tree, because the bug is resolved there by a series
>  of 4 patches (see the below).
> 
> IMO it's better to apply this small patch to the stable kernels rather than 
> backporting the 4 big commits?

It is always better to backport the original commits.  Will they work
as-is, or do they need porting?

thanks,

greg k-h

Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()

[Stephen Hemminger]

On Thu, 7 Sep 2017 06:27:25 +0200
Greg KH <gregkh@linuxfoundation.org> wrote:

> On Thu, Sep 07, 2017 at 12:54:09AM +0000, Dexuan Cui wrote:
> > > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > > Sent: Wednesday, August 16, 2017 9:16 AM
> > > To: Greg KH <gregkh@linuxfoundation.org>
> > > Cc: KY Srinivasan <kys@microsoft.com>; Dexuan Cui <decui@microsoft.com>;
> > > devel@linuxdriverproject.org; linux-kernel@vger.kernel.org;
> > > stable@vger.kernel.org; Stephen Hemminger <sthemmin@microsoft.com>;
> > > John Starks <jon.Starks@microsoft.com>
> > > Subject: Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()
> > > 
> > > On Wed, 16 Aug 2017 09:10:40 -0700
> > > Greg KH <gregkh@linuxfoundation.org> wrote:
> > >   
> > > > On Wed, Aug 16, 2017 at 08:49:46AM -0700, Stephen Hemminger wrote:  
> > > > > When the space available before start of reading (cached_write_sz)
> > > > > is the same as the host required space (pending_sz), we need to
> > > > > still signal host.
> > > > >
> > > > > Fixes: 433e19cf33d3 ("Drivers: hv: vmbus: finally fix  
> > > hv_need_to_signal_on_read()")  
> > > > >
> > > > > Signed-off-by: John Starks <jon.Starks@microsoft.com>
> > > > > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > > > > Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
> > > > > ---
> > > > > This patch is for 4.13 (and stable).
> > > > > A different fix is needed for linux-next.  
> > > >
> > > > Is there a fix for this in Linus's tree?  If so, what's the git commit
> > > > id?  We need to wait for that until I can take it in -stable.  
> > > 
> > > There is no commit yet in Linus's tree. Was submitting for both Linus
> > > and stable. Wasn't sure about the timing since 4.13 might close before he gets
> > > to it.  
> > 
> > Hi Greg and stable@vger.kernel.org,
> > We need the patch for the stable kernels:  v4.13, v4.12.10 and v4.9.47.
> > 
> > The patch is not in Linus's tree, because the bug is resolved there by a series
> >  of 4 patches (see the below).
> > 
> > IMO it's better to apply this small patch to the stable kernels rather than 
> > backporting the 4 big commits?  
> 
> It is always better to backport the original commits.  Will they work
> as-is, or do they need porting?

I will try for 4.13 but going back to 4.9 might be hard.

Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()

[Stephen Hemminger]

On Thu, 7 Sep 2017 06:27:25 +0200
Greg KH <gregkh@linuxfoundation.org> wrote:

> On Thu, Sep 07, 2017 at 12:54:09AM +0000, Dexuan Cui wrote:
> > > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > > Sent: Wednesday, August 16, 2017 9:16 AM
> > > To: Greg KH <gregkh@linuxfoundation.org>
> > > Cc: KY Srinivasan <kys@microsoft.com>; Dexuan Cui <decui@microsoft.com>;
> > > devel@linuxdriverproject.org; linux-kernel@vger.kernel.org;
> > > stable@vger.kernel.org; Stephen Hemminger <sthemmin@microsoft.com>;
> > > John Starks <jon.Starks@microsoft.com>
> > > Subject: Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()
> > > 
> > > On Wed, 16 Aug 2017 09:10:40 -0700
> > > Greg KH <gregkh@linuxfoundation.org> wrote:
> > >   
> > > > On Wed, Aug 16, 2017 at 08:49:46AM -0700, Stephen Hemminger wrote:  
> > > > > When the space available before start of reading (cached_write_sz)
> > > > > is the same as the host required space (pending_sz), we need to
> > > > > still signal host.
> > > > >
> > > > > Fixes: 433e19cf33d3 ("Drivers: hv: vmbus: finally fix  
> > > hv_need_to_signal_on_read()")  
> > > > >
> > > > > Signed-off-by: John Starks <jon.Starks@microsoft.com>
> > > > > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > > > > Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
> > > > > ---
> > > > > This patch is for 4.13 (and stable).
> > > > > A different fix is needed for linux-next.  
> > > >
> > > > Is there a fix for this in Linus's tree?  If so, what's the git commit
> > > > id?  We need to wait for that until I can take it in -stable.  
> > > 
> > > There is no commit yet in Linus's tree. Was submitting for both Linus
> > > and stable. Wasn't sure about the timing since 4.13 might close before he gets
> > > to it.  
> > 
> > Hi Greg and stable@vger.kernel.org,
> > We need the patch for the stable kernels:  v4.13, v4.12.10 and v4.9.47.
> > 
> > The patch is not in Linus's tree, because the bug is resolved there by a series
> >  of 4 patches (see the below).
> > 
> > IMO it's better to apply this small patch to the stable kernels rather than 
> > backporting the 4 big commits?  
> 
> It is always better to backport the original commits.  Will they work
> as-is, or do they need porting?
> 
> thanks,
> 
> greg k-h

The four patches apply (and kernel builds and runs) for 4.12.10 and 4.13.
They do not apply to 4.9 unless several other patches are  dragged in.

Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()

[Greg KH]

On Thu, Sep 07, 2017 at 08:41:13AM -0700, Stephen Hemminger wrote:
> On Thu, 7 Sep 2017 06:27:25 +0200
> Greg KH <gregkh@linuxfoundation.org> wrote:
> 
> > On Thu, Sep 07, 2017 at 12:54:09AM +0000, Dexuan Cui wrote:
> > > > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > > > Sent: Wednesday, August 16, 2017 9:16 AM
> > > > To: Greg KH <gregkh@linuxfoundation.org>
> > > > Cc: KY Srinivasan <kys@microsoft.com>; Dexuan Cui <decui@microsoft.com>;
> > > > devel@linuxdriverproject.org; linux-kernel@vger.kernel.org;
> > > > stable@vger.kernel.org; Stephen Hemminger <sthemmin@microsoft.com>;
> > > > John Starks <jon.Starks@microsoft.com>
> > > > Subject: Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()
> > > > 
> > > > On Wed, 16 Aug 2017 09:10:40 -0700
> > > > Greg KH <gregkh@linuxfoundation.org> wrote:
> > > >   
> > > > > On Wed, Aug 16, 2017 at 08:49:46AM -0700, Stephen Hemminger wrote:  
> > > > > > When the space available before start of reading (cached_write_sz)
> > > > > > is the same as the host required space (pending_sz), we need to
> > > > > > still signal host.
> > > > > >
> > > > > > Fixes: 433e19cf33d3 ("Drivers: hv: vmbus: finally fix  
> > > > hv_need_to_signal_on_read()")  
> > > > > >
> > > > > > Signed-off-by: John Starks <jon.Starks@microsoft.com>
> > > > > > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > > > > > Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
> > > > > > ---
> > > > > > This patch is for 4.13 (and stable).
> > > > > > A different fix is needed for linux-next.  
> > > > >
> > > > > Is there a fix for this in Linus's tree?  If so, what's the git commit
> > > > > id?  We need to wait for that until I can take it in -stable.  
> > > > 
> > > > There is no commit yet in Linus's tree. Was submitting for both Linus
> > > > and stable. Wasn't sure about the timing since 4.13 might close before he gets
> > > > to it.  
> > > 
> > > Hi Greg and stable@vger.kernel.org,
> > > We need the patch for the stable kernels:  v4.13, v4.12.10 and v4.9.47.
> > > 
> > > The patch is not in Linus's tree, because the bug is resolved there by a series
> > >  of 4 patches (see the below).
> > > 
> > > IMO it's better to apply this small patch to the stable kernels rather than 
> > > backporting the 4 big commits?  
> > 
> > It is always better to backport the original commits.  Will they work
> > as-is, or do they need porting?
> > 
> > thanks,
> > 
> > greg k-h
> 
> The four patches apply (and kernel builds and runs) for 4.12.10 and 4.13.
> They do not apply to 4.9 unless several other patches are  dragged in.

Ok, any suggestion of what I should do here?  Drag in the series for
4.13?  Something else for 4.9?  As long as you all are willing to
"support" whatever we do here, I'll go along with it...

thanks,

greg k-h

Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()

[Stephen Hemminger]

On Tue, 10 Oct 2017 17:01:29 +0200
Greg KH <gregkh@linuxfoundation.org> wrote:

> On Thu, Sep 07, 2017 at 08:41:13AM -0700, Stephen Hemminger wrote:
> > On Thu, 7 Sep 2017 06:27:25 +0200
> > Greg KH <gregkh@linuxfoundation.org> wrote:
> >   
> > > On Thu, Sep 07, 2017 at 12:54:09AM +0000, Dexuan Cui wrote:  
> > > > > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > > > > Sent: Wednesday, August 16, 2017 9:16 AM
> > > > > To: Greg KH <gregkh@linuxfoundation.org>
> > > > > Cc: KY Srinivasan <kys@microsoft.com>; Dexuan Cui <decui@microsoft.com>;
> > > > > devel@linuxdriverproject.org; linux-kernel@vger.kernel.org;
> > > > > stable@vger.kernel.org; Stephen Hemminger <sthemmin@microsoft.com>;
> > > > > John Starks <jon.Starks@microsoft.com>
> > > > > Subject: Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()
> > > > > 
> > > > > On Wed, 16 Aug 2017 09:10:40 -0700
> > > > > Greg KH <gregkh@linuxfoundation.org> wrote:
> > > > >     
> > > > > > On Wed, Aug 16, 2017 at 08:49:46AM -0700, Stephen Hemminger wrote:    
> > > > > > > When the space available before start of reading (cached_write_sz)
> > > > > > > is the same as the host required space (pending_sz), we need to
> > > > > > > still signal host.
> > > > > > >
> > > > > > > Fixes: 433e19cf33d3 ("Drivers: hv: vmbus: finally fix    
> > > > > hv_need_to_signal_on_read()")    
> > > > > > >
> > > > > > > Signed-off-by: John Starks <jon.Starks@microsoft.com>
> > > > > > > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > > > > > > Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
> > > > > > > ---
> > > > > > > This patch is for 4.13 (and stable).
> > > > > > > A different fix is needed for linux-next.    
> > > > > >
> > > > > > Is there a fix for this in Linus's tree?  If so, what's the git commit
> > > > > > id?  We need to wait for that until I can take it in -stable.    
> > > > > 
> > > > > There is no commit yet in Linus's tree. Was submitting for both Linus
> > > > > and stable. Wasn't sure about the timing since 4.13 might close before he gets
> > > > > to it.    
> > > > 
> > > > Hi Greg and stable@vger.kernel.org,
> > > > We need the patch for the stable kernels:  v4.13, v4.12.10 and v4.9.47.
> > > > 
> > > > The patch is not in Linus's tree, because the bug is resolved there by a series
> > > >  of 4 patches (see the below).
> > > > 
> > > > IMO it's better to apply this small patch to the stable kernels rather than 
> > > > backporting the 4 big commits?    
> > > 
> > > It is always better to backport the original commits.  Will they work
> > > as-is, or do they need porting?
> > > 
> > > thanks,
> > > 
> > > greg k-h  
> > 
> > The four patches apply (and kernel builds and runs) for 4.12.10 and 4.13.
> > They do not apply to 4.9 unless several other patches are  dragged in.  
> 
> Ok, any suggestion of what I should do here?  Drag in the series for
> 4.13?  Something else for 4.9?  As long as you all are willing to
> "support" whatever we do here, I'll go along with it...
> 
> thanks,
> 
> greg k-h

I would prefer the single patch for 4.9 rather than creating increased
risk by dragging in the full patch set.

RE: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()

[KY Srinivasan]

> -----Original Message-----
> From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> Sent: Wednesday, October 11, 2017 9:56 AM
> To: Greg KH <gregkh@linuxfoundation.org>
> Cc: Dexuan Cui <decui@microsoft.com>; stable@vger.kernel.org; KY
> Srinivasan <kys@microsoft.com>; Stephen Hemminger
> <sthemmin@microsoft.com>
> Subject: Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()
> 
> On Tue, 10 Oct 2017 17:01:29 +0200
> Greg KH <gregkh@linuxfoundation.org> wrote:
> 
> > On Thu, Sep 07, 2017 at 08:41:13AM -0700, Stephen Hemminger wrote:
> > > On Thu, 7 Sep 2017 06:27:25 +0200
> > > Greg KH <gregkh@linuxfoundation.org> wrote:
> > >
> > > > On Thu, Sep 07, 2017 at 12:54:09AM +0000, Dexuan Cui wrote:
> > > > > > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > > > > > Sent: Wednesday, August 16, 2017 9:16 AM
> > > > > > To: Greg KH <gregkh@linuxfoundation.org>
> > > > > > Cc: KY Srinivasan <kys@microsoft.com>; Dexuan Cui
> <decui@microsoft.com>;
> > > > > > devel@linuxdriverproject.org; linux-kernel@vger.kernel.org;
> > > > > > stable@vger.kernel.org; Stephen Hemminger
> <sthemmin@microsoft.com>;
> > > > > > John Starks <jon.Starks@microsoft.com>
> > > > > > Subject: Re: [PATCH] vmbus: fix missing signaling in
> hv_signal_on_read()
> > > > > >
> > > > > > On Wed, 16 Aug 2017 09:10:40 -0700
> > > > > > Greg KH <gregkh@linuxfoundation.org> wrote:
> > > > > >
> > > > > > > On Wed, Aug 16, 2017 at 08:49:46AM -0700, Stephen Hemminger
> wrote:
> > > > > > > > When the space available before start of reading
> (cached_write_sz)
> > > > > > > > is the same as the host required space (pending_sz), we need to
> > > > > > > > still signal host.
> > > > > > > >
> > > > > > > > Fixes: 433e19cf33d3 ("Drivers: hv: vmbus: finally fix
> > > > > > hv_need_to_signal_on_read()")
> > > > > > > >
> > > > > > > > Signed-off-by: John Starks <jon.Starks@microsoft.com>
> > > > > > > > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > > > > > > > Signed-off-by: Stephen Hemminger
> <sthemmin@microsoft.com>
> > > > > > > > ---
> > > > > > > > This patch is for 4.13 (and stable).
> > > > > > > > A different fix is needed for linux-next.
> > > > > > >
> > > > > > > Is there a fix for this in Linus's tree?  If so, what's the git commit
> > > > > > > id?  We need to wait for that until I can take it in -stable.
> > > > > >
> > > > > > There is no commit yet in Linus's tree. Was submitting for both Linus
> > > > > > and stable. Wasn't sure about the timing since 4.13 might close
> before he gets
> > > > > > to it.
> > > > >
> > > > > Hi Greg and stable@vger.kernel.org,
> > > > > We need the patch for the stable kernels:  v4.13, v4.12.10 and v4.9.47.
> > > > >
> > > > > The patch is not in Linus's tree, because the bug is resolved there by a
> series
> > > > >  of 4 patches (see the below).
> > > > >
> > > > > IMO it's better to apply this small patch to the stable kernels rather
> than
> > > > > backporting the 4 big commits?
> > > >
> > > > It is always better to backport the original commits.  Will they work
> > > > as-is, or do they need porting?
> > > >
> > > > thanks,
> > > >
> > > > greg k-h
> > >
> > > The four patches apply (and kernel builds and runs) for 4.12.10 and 4.13.
> > > They do not apply to 4.9 unless several other patches are  dragged in.
> >
> > Ok, any suggestion of what I should do here?  Drag in the series for
> > 4.13?  Something else for 4.9?  As long as you all are willing to
> > "support" whatever we do here, I'll go along with it...
> >
> > thanks,
> >
> > greg k-h
> 
> I would prefer the single patch for 4.9 rather than creating increased
> risk by dragging in the full patch set.

I agree. Just to reiterate, we will apply the series for 4.13 and will submit a 
single patch for 4.9.

K. Y

RE: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()

[Dexuan Cui]

> -----Original Message-----
> From: KY Srinivasan
> Sent: Wednesday, October 11, 2017 11:10 AM
> To: Stephen Hemminger <stephen@networkplumber.org>; Greg KH
> <gregkh@linuxfoundation.org>
> Cc: Dexuan Cui <decui@microsoft.com>; stable@vger.kernel.org; Stephen
> Hemminger <sthemmin@microsoft.com>
> Subject: RE: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()
> > -----Original Message-----
> > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > Sent: Wednesday, October 11, 2017 9:56 AM
> > To: Greg KH <gregkh@linuxfoundation.org>
> > Cc: Dexuan Cui <decui@microsoft.com>; stable@vger.kernel.org; KY
> > Srinivasan <kys@microsoft.com>; Stephen Hemminger
> > <sthemmin@microsoft.com>
> > Subject: Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()
> >
> > On Tue, 10 Oct 2017 17:01:29 +0200
> > Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> > > On Thu, Sep 07, 2017 at 08:41:13AM -0700, Stephen Hemminger wrote:
> > > > On Thu, 7 Sep 2017 06:27:25 +0200
> > > > Greg KH <gregkh@linuxfoundation.org> wrote:
> > > >
> > > > > On Thu, Sep 07, 2017 at 12:54:09AM +0000, Dexuan Cui wrote:
> > > > > > > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > > > > > > Sent: Wednesday, August 16, 2017 9:16 AM
> > > > > > > To: Greg KH <gregkh@linuxfoundation.org>
> > > > > > > Cc: KY Srinivasan <kys@microsoft.com>; Dexuan Cui
> > <decui@microsoft.com>;
> > > > > > > devel@linuxdriverproject.org; linux-kernel@vger.kernel.org;
> > > > > > > stable@vger.kernel.org; Stephen Hemminger
> > <sthemmin@microsoft.com>;
> > > > > > > John Starks <jon.Starks@microsoft.com>
> > > > > > > Subject: Re: [PATCH] vmbus: fix missing signaling in
> > hv_signal_on_read()
> > > > > > >
> > > > > > > On Wed, 16 Aug 2017 09:10:40 -0700
> > > > > > > Greg KH <gregkh@linuxfoundation.org> wrote:
> > > > > > >
> > > > > > > > On Wed, Aug 16, 2017 at 08:49:46AM -0700, Stephen Hemminger
> > wrote:
> > > > > > > > > When the space available before start of reading
> > (cached_write_sz)
> > > > > > > > > is the same as the host required space (pending_sz), we need to
> > > > > > > > > still signal host.
> > > > > > > > >
> > > > > > > > > Fixes: 433e19cf33d3 ("Drivers: hv: vmbus: finally fix
> > > > > > > hv_need_to_signal_on_read()")
> > > > > > > > >
> > > > > > > > > Signed-off-by: John Starks <jon.Starks@microsoft.com>
> > > > > > > > > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > > > > > > > > Signed-off-by: Stephen Hemminger
> > <sthemmin@microsoft.com>
> > > > > > > > > ---
> > > > > > > > > This patch is for 4.13 (and stable).
> > > > > > > > > A different fix is needed for linux-next.
> > > > > > > >
> > > > > > > > Is there a fix for this in Linus's tree?  If so, what's the git commit
> > > > > > > > id?  We need to wait for that until I can take it in -stable.
> > > > > > >
> > > > > > > There is no commit yet in Linus's tree. Was submitting for both Linus
> > > > > > > and stable. Wasn't sure about the timing since 4.13 might close
> > before he gets
> > > > > > > to it.
> > > > > >
> > > > > > Hi Greg and stable@vger.kernel.org,
> > > > > > We need the patch for the stable kernels:  v4.13, v4.12.10 and v4.9.47.
> > > > > >
> > > > > > The patch is not in Linus's tree, because the bug is resolved there by a
> > series
> > > > > >  of 4 patches (see the below).
> > > > > >
> > > > > > IMO it's better to apply this small patch to the stable kernels rather
> > than
> > > > > > backporting the 4 big commits?
> > > > >
> > > > > It is always better to backport the original commits.  Will they work
> > > > > as-is, or do they need porting?
> > > > >
> > > > > thanks,
> > > > >
> > > > > greg k-h
> > > >
> > > > The four patches apply (and kernel builds and runs) for 4.12.10 and 4.13.
> > > > They do not apply to 4.9 unless several other patches are  dragged in.
> > >
> > > Ok, any suggestion of what I should do here?  Drag in the series for
> > > 4.13?  Something else for 4.9?  As long as you all are willing to
> > > "support" whatever we do here, I'll go along with it...
> > >
> > > thanks,
> > >
> > > greg k-h
> >
> > I would prefer the single patch for 4.9 rather than creating increased
> > risk by dragging in the full patch set.
> 
> I agree. Just to reiterate, we will apply the series for 4.13 and will submit a
> single patch for 4.9.
> 
> K. Y

Hi Greg,
Just in case, let me provide the detailed information for your convenience:

For v4.9.56, we need this single patch (should Stephen or I re-submit it?):
https://patchwork.kernel.org/patch/9904081/
It can apply clean with fuzz 2 (offset 6 lines).

For v4.13.6 and v4.12.9, we need these 4 paches below (the commit IDs are
>From Linus's tree), and I have verified they can apply cleanly:

commit 4226ff69a3dff78bead7d9a270423cd21f8d40b8
Author: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
Date:   Sun Jun 25 12:30:24 2017 -0700

    vmbus: simplify hv_ringbuffer_read

    With new iterator functions (and the double mapping) the ring buffer
    read function can be greatly simplified.

    Signed-off-by: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
    Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
    Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>


commit 8dd45f2ab005a1f3301296059b23b03ec3dbf79b
Author: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
Date:   Sun Jun 25 12:30:26 2017 -0700

    vmbus: refactor hv_signal_on_read

    The function hv_signal_on_read was defined in hyperv.h and
    only used in one place in ring_buffer code. Clearer to just
    move it inline there.

    Signed-off-by: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
    Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
    Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>


commit 05d00bc94ac27d220d8a78e365d7fa3a26dcca17
Author: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
Date:   Sun Jun 25 12:30:27 2017 -0700

    vmbus: eliminate duplicate cached index

    Don't need cached read index anymore now that packet iterator
    is used. The iterator has the original read index until the
    visible read_index is updated.

    Signed-off-by: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
    Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
    Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>



commit 03bad714a1619c0074eb44d6f217c505fe27030f
Author: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
Date:   Sun Jun 25 12:30:28 2017 -0700

    vmbus: more host signalling avoidance

    Don't signal host if it has disabled interrupts for that
    ring buffer. Check the feature bit to see if host supports
    pending send size flag.

    Signed-off-by: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
    Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
    Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

Thanks,
-- Dexuan

Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()

[Greg KH]

On Fri, Oct 13, 2017 at 05:55:46PM +0000, Dexuan Cui wrote:
> > -----Original Message-----
> > From: KY Srinivasan
> > Sent: Wednesday, October 11, 2017 11:10 AM
> > To: Stephen Hemminger <stephen@networkplumber.org>; Greg KH
> > <gregkh@linuxfoundation.org>
> > Cc: Dexuan Cui <decui@microsoft.com>; stable@vger.kernel.org; Stephen
> > Hemminger <sthemmin@microsoft.com>
> > Subject: RE: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()
> > > -----Original Message-----
> > > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > > Sent: Wednesday, October 11, 2017 9:56 AM
> > > To: Greg KH <gregkh@linuxfoundation.org>
> > > Cc: Dexuan Cui <decui@microsoft.com>; stable@vger.kernel.org; KY
> > > Srinivasan <kys@microsoft.com>; Stephen Hemminger
> > > <sthemmin@microsoft.com>
> > > Subject: Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()
> > >
> > > On Tue, 10 Oct 2017 17:01:29 +0200
> > > Greg KH <gregkh@linuxfoundation.org> wrote:
> > >
> > > > On Thu, Sep 07, 2017 at 08:41:13AM -0700, Stephen Hemminger wrote:
> > > > > On Thu, 7 Sep 2017 06:27:25 +0200
> > > > > Greg KH <gregkh@linuxfoundation.org> wrote:
> > > > >
> > > > > > On Thu, Sep 07, 2017 at 12:54:09AM +0000, Dexuan Cui wrote:
> > > > > > > > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > > > > > > > Sent: Wednesday, August 16, 2017 9:16 AM
> > > > > > > > To: Greg KH <gregkh@linuxfoundation.org>
> > > > > > > > Cc: KY Srinivasan <kys@microsoft.com>; Dexuan Cui
> > > <decui@microsoft.com>;
> > > > > > > > devel@linuxdriverproject.org; linux-kernel@vger.kernel.org;
> > > > > > > > stable@vger.kernel.org; Stephen Hemminger
> > > <sthemmin@microsoft.com>;
> > > > > > > > John Starks <jon.Starks@microsoft.com>
> > > > > > > > Subject: Re: [PATCH] vmbus: fix missing signaling in
> > > hv_signal_on_read()
> > > > > > > >
> > > > > > > > On Wed, 16 Aug 2017 09:10:40 -0700
> > > > > > > > Greg KH <gregkh@linuxfoundation.org> wrote:
> > > > > > > >
> > > > > > > > > On Wed, Aug 16, 2017 at 08:49:46AM -0700, Stephen Hemminger
> > > wrote:
> > > > > > > > > > When the space available before start of reading
> > > (cached_write_sz)
> > > > > > > > > > is the same as the host required space (pending_sz), we need to
> > > > > > > > > > still signal host.
> > > > > > > > > >
> > > > > > > > > > Fixes: 433e19cf33d3 ("Drivers: hv: vmbus: finally fix
> > > > > > > > hv_need_to_signal_on_read()")
> > > > > > > > > >
> > > > > > > > > > Signed-off-by: John Starks <jon.Starks@microsoft.com>
> > > > > > > > > > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > > > > > > > > > Signed-off-by: Stephen Hemminger
> > > <sthemmin@microsoft.com>
> > > > > > > > > > ---
> > > > > > > > > > This patch is for 4.13 (and stable).
> > > > > > > > > > A different fix is needed for linux-next.
> > > > > > > > >
> > > > > > > > > Is there a fix for this in Linus's tree?  If so, what's the git commit
> > > > > > > > > id?  We need to wait for that until I can take it in -stable.
> > > > > > > >
> > > > > > > > There is no commit yet in Linus's tree. Was submitting for both Linus
> > > > > > > > and stable. Wasn't sure about the timing since 4.13 might close
> > > before he gets
> > > > > > > > to it.
> > > > > > >
> > > > > > > Hi Greg and stable@vger.kernel.org,
> > > > > > > We need the patch for the stable kernels:  v4.13, v4.12.10 and v4.9.47.
> > > > > > >
> > > > > > > The patch is not in Linus's tree, because the bug is resolved there by a
> > > series
> > > > > > >  of 4 patches (see the below).
> > > > > > >
> > > > > > > IMO it's better to apply this small patch to the stable kernels rather
> > > than
> > > > > > > backporting the 4 big commits?
> > > > > >
> > > > > > It is always better to backport the original commits.  Will they work
> > > > > > as-is, or do they need porting?
> > > > > >
> > > > > > thanks,
> > > > > >
> > > > > > greg k-h
> > > > >
> > > > > The four patches apply (and kernel builds and runs) for 4.12.10 and 4.13.
> > > > > They do not apply to 4.9 unless several other patches are  dragged in.
> > > >
> > > > Ok, any suggestion of what I should do here?  Drag in the series for
> > > > 4.13?  Something else for 4.9?  As long as you all are willing to
> > > > "support" whatever we do here, I'll go along with it...
> > > >
> > > > thanks,
> > > >
> > > > greg k-h
> > >
> > > I would prefer the single patch for 4.9 rather than creating increased
> > > risk by dragging in the full patch set.
> > 
> > I agree. Just to reiterate, we will apply the series for 4.13 and will submit a
> > single patch for 4.9.
> > 
> > K. Y
> 
> Hi Greg,
> Just in case, let me provide the detailed information for your convenience:
> 
> For v4.9.56, we need this single patch (should Stephen or I re-submit it?):
> https://patchwork.kernel.org/patch/9904081/
> It can apply clean with fuzz 2 (offset 6 lines).

Please resend it, with no fuzz, so I know you have properly generated it
and tested it :)

> For v4.13.6 and v4.12.9, we need these 4 paches below (the commit IDs are
> >From Linus's tree), and I have verified they can apply cleanly:

4.12 is end-of-life :)

But I've now applied these 4 patches to the 4.13-stable tree.

thanks,

greg k-h

RE: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()

[Dexuan Cui]

> From: Greg KH [mailto:gregkh@linuxfoundation.org]
> Sent: Thursday, October 19, 2017 6:13 AM
> ...
> > Hi Greg,
> > Just in case, let me provide the detailed information for your convenience:
> >
> > For v4.9.56, we need this single patch (should Stephen or I re-submit it?):
> >
> > https://patchwork.kernel.org/patch/9904081/
> > It can apply clean with fuzz 2 (offset 6 lines).
> 
> Please resend it, with no fuzz, so I know you have properly generated it
> and tested it :)

OK, I rebased & re-sent it to you and stable@vger.kernel.org just now with
the subject:
"[PATCH] [linux-4.9.y only] vmbus: fix missing signaling in hv_signal_on_read()"

Please apply it to linux-4.9.y.

> > For v4.13.6 and v4.12.9, we need these 4 paches below (the commit IDs are
> > >From Linus's tree), and I have verified they can apply cleanly:
> 
> 4.12 is end-of-life :)
> 
> But I've now applied these 4 patches to the 4.13-stable tree.
> greg k-h

Thanks, Greg!

Thanks,
-- Dexuan