From: "Radim Krčmář" <rkrcmar-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
To: Vitaly Kuznetsov <vkuznets-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: "K. Y. Srinivasan" <kys-0li6OtcxBFHby3iVrkZq2A@public.gmane.org>,
devel-tBiZLqfeLfOHmIFyCCdPziST3g8Odh+X@public.gmane.org,
Haiyang Zhang <haiyangz-0li6OtcxBFHby3iVrkZq2A@public.gmane.org>,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Dexuan Cui <decui-0li6OtcxBFHby3iVrkZq2A@public.gmane.org>,
Greg Kroah-Hartman
<gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>,
linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH RFC 1/3] Drivers: hv: kvp: convert userspace/kernel communication to using char device
Date: Fri, 27 Feb 2015 21:27:15 +0100 [thread overview]
Message-ID: <20150227202715.GF2034@potion.brq.redhat.com> (raw)
In-Reply-To: <1425053665-635-2-git-send-email-vkuznets-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2015-02-27 17:14+0100, Vitaly Kuznetsov:
> Re-implement the communication using misc char device. Use ioctl to do
> kernel/userspace version negotiation (doesn't make much sense at this moment
> as we're breaking backwards compatibility but can be used in future).
The main question is whether we want to abolish backward compatibility;
kernel rules are usually against breakages and it's hard to prove that
the bundled daemon is a sole user and gets updated at the same time.
(Note: I'd gladly break anything.)
The ioctl is used too creatively for my liking: as an out-of-band
communication that is required after the main channel has been opened.
It would be simpler to inject the version into first x bytes of the
stream, making a read() after open() mandatory.
(I've only done a high level overview so far.)
next prev parent reply other threads:[~2015-02-27 20:27 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-27 16:14 [PATCH RFC 0/3] Drivers: hv: utils: re-implement the kernel/userspace communication layer Vitaly Kuznetsov
2015-02-27 16:14 ` [PATCH RFC 1/3] Drivers: hv: kvp: convert userspace/kernel communication to using char device Vitaly Kuznetsov
[not found] ` <1425053665-635-2-git-send-email-vkuznets-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2015-02-27 20:27 ` Radim Krčmář [this message]
2015-03-03 9:53 ` Vitaly Kuznetsov
[not found] ` <87pp8qif00.fsf-hpI3/L/TUU23oHxwIazZmlaTQe2KTcn/@public.gmane.org>
2015-03-03 19:47 ` Radim Krčmář
2015-02-27 16:14 ` [PATCH RFC 2/3] Drivers: hv: vss: " Vitaly Kuznetsov
2015-02-27 16:14 ` [PATCH RFC 3/3] Drivers: hv: fcopy: make it consistent with vss/kvp Vitaly Kuznetsov
[not found] ` <1425053665-635-1-git-send-email-vkuznets-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2015-02-27 21:07 ` [PATCH RFC 0/3] Drivers: hv: utils: re-implement the kernel/userspace communication layer Radim Krčmář
[not found] ` <20150227210744.GA11904-KfRq7+sF/6zkZJWtSm8s3NvLeJWuRmrY@public.gmane.org>
2015-03-02 13:33 ` Vitaly Kuznetsov
2015-03-02 2:11 ` KY Srinivasan
2015-03-02 13:37 ` Vitaly Kuznetsov
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