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Date:   Tue, 6 Dec 2022 15:31:26 +0100
From:   Christoph Hellwig <hch@lst.de>
To:     Jason Gunthorpe <jgg@ziepe.ca>
Cc:     Christoph Hellwig <hch@lst.de>, Lei Rao <lei.rao@intel.com>,
        kbusch@kernel.org, axboe@fb.com, kch@nvidia.com, sagi@grimberg.me,
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        shameerali.kolothum.thodi@huawei.com, kevin.tian@intel.com,
        mjrosato@linux.ibm.com, linux-kernel@vger.kernel.org,
        linux-nvme@lists.infradead.org, kvm@vger.kernel.org,
        eddie.dong@intel.com, yadong.li@intel.com, yi.l.liu@intel.com,
        Konrad.wilk@oracle.com, stephen@eideticom.com, hang.yuan@intel.com
Subject: Re: [RFC PATCH 5/5] nvme-vfio: Add a document for the NVMe device
Message-ID: <20221206143126.GB30297@lst.de>
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On Tue, Dec 06, 2022 at 10:20:26AM -0400, Jason Gunthorpe wrote:
> In the VFIO restore model there is no "live OS" on resume. The
> load/resume cycle is as destructive as reset to the vfio device.

Of course there may be and OS.  As soon as the VF is live Linux
will by default bind to it.  And that's the big problem here,
the VF should not actually exist or at least not be usable when
such a restore happens - or to say it in NVMe terms, the Secondary
Controller better be in offline state when state is loaded into it.