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Date:   Wed, 11 May 2022 14:42:04 +0000
From:   Wei Liu <wei.liu@kernel.org>
To:     Michael Kelley <mikelley@microsoft.com>
Cc:     kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com,
        wei.liu@kernel.org, linux-kernel@vger.kernel.org,
        linux-hyperv@vger.kernel.org, vkuznets@redhat.com,
        decui@microsoft.com, drawat.floss@gmail.com, airlied@linux.ie,
        daniel@ffwll.ch, jejb@linux.ibm.com, martin.petersen@oracle.com,
        deller@gmx.de, dri-devel@lists.freedesktop.org,
        linux-scsi@vger.kernel.org, linux-fbdev@vger.kernel.org
Subject: Re: [PATCH 0/4] Remove support for Hyper-V 2008 and 2008R2/Win7
Message-ID: <20220511144204.ilpsk2oiyknh7cys@liuwe-devbox-debian-v2>
References: <1651509391-2058-1-git-send-email-mikelley@microsoft.com>
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On Mon, May 02, 2022 at 09:36:27AM -0700, Michael Kelley wrote:
> Linux code for running as a Hyper-V guest includes special cases for the
> first released versions of Hyper-V: 2008 and 2008R2/Windows 7. These
> versions were very thinly used for running Linux guests when first
> released more than 12 years ago, and they are now out of support
> (except for extended security updates). As initial versions, they
> lack the performance features needed for effective production usage
> of Linux guests. In total, there's no need to continue to support
> the latest Linux kernels on these versions of Hyper-V.
> 
> Simplify the code for running on Hyper-V by removing the special
> cases. This includes removing the negotiation of the VMbus protocol
> versions for 2008 and 2008R2, and the special case code based on
> those VMbus protocol versions. Changes are in the core VMbus code and
> several drivers for synthetic VMbus devices.
> 
> Some drivers have driver-specific protocols with the Hyper-V host and
> may have versions of those protocols that are limited to 2008 and
> 2008R2. This patch set does the clean-up only for the top-level
> VMbus protocol versions, and not the driver-specific protocols.
> Cleaning up the driver-specific protocols can be done with
> follow-on patches.
> 
> There's no specific urgency to removing the special case code for
> 2008 and 2008R2, so if the broader Linux kernel community surfaces
> a reason why this clean-up should not be done now, we can wait.
> But I think we want to eventually stop carrying around this extra
> baggage, and based on discussions with the Hyper-V team within
> Microsoft, we're already past the point that it has any value.
> 
> Michael Kelley (4):
>   Drivers: hv: vmbus: Remove support for Hyper-V 2008 and Hyper-V
>     2008R2/Win7
>   scsi: storvsc: Remove support for Hyper-V 2008 and 2008R2/Win7
>   video: hyperv_fb: Remove support for Hyper-V 2008 and 2008R2/Win7
>   drm/hyperv: Remove support for Hyper-V 2008 and 2008R2/Win7

Applied to hyperv-next.