RE: [PATCH 1/1] Drivers: hv: vmbus: Fix ring buffer signaling

[Stephen Hemminger]

Thanks, I hadn't updated to rc7 yet


-----Original Message-----
From: Joshua R. Poulson <jrp@xxxxxxx> 
Sent: Wednesday, March 28, 2018 12:18 PM
To: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
Cc: K. Y. Srinivasan <kys@xxxxxxxxxxxxxxxxxxxxxx>; KY Srinivasan <kys@xxxxxxxxxxxxx>; gregkh@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx; olaf@xxxxxxxxx; Andy Whitcroft <apw@xxxxxxxxxxxxx>; Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>; jasowang@xxxxxxxxxx; Leann Ogasawara <leann.ogasawara@xxxxxxxxxxxxx>; Marcelo Henrique Cerri <marcelo.cerri@xxxxxxxxxxxxx>; Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>; Michael Kelley <mhkelley@xxxxxxxxxxx>; Stable <stable@xxxxxxxxxxxxxxx>
Subject: Re: [PATCH 1/1] Drivers: hv: vmbus: Fix ring buffer signaling

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v4.16-rc7&id=655296c8bbeffcf020558c4455305d597a73bde1

On Wed, Mar 28, 2018 at 12:01 PM, Stephen Hemminger
<stephen@xxxxxxxxxxxxxxxxxx> wrote:
> On Sun,  4 Mar 2018 22:24:08 -0700
> kys@xxxxxxxxxxxxxxxxxxxxxx wrote:
>
>> From: Michael Kelley <mhkelley@xxxxxxxxxxx>
>>
>> Fix bugs in signaling the Hyper-V host when freeing space in the
>> host->guest ring buffer:
>>
>> 1. The interrupt_mask must not be used to determine whether to signal
>>    on the host->guest ring buffer
>> 2. The ring buffer write_index must be read (via hv_get_bytes_to_write)
>>    *after* pending_send_sz is read in order to avoid a race condition
>> 3. Comparisons with pending_send_sz must treat the "equals" case as
>>    not-enough-space
>> 4. Don't signal if the pending_send_sz feature is not present. Older
>>    versions of Hyper-V that don't implement this feature will poll.
>>
>> Fixes: 03bad714a161 ("vmbus: more host signalling avoidance")
>>
>> Cc: Stable <stable@xxxxxxxxxxxxxxx> # 4.14 and above
>> Signed-off-by: Michael Kelley <mhkelley@xxxxxxxxxxx>
>> Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
>
> What ever happened to this patch? It doesn't seem to be in char-misc, upstream,
> or stable kernel tree yet.
>
>