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Date:   Fri, 3 May 2019 05:29:02 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     Maxim Levitsky <mlevitsk@redhat.com>
Cc:     linux-nvme@lists.infradead.org, Fam Zheng <fam@euphon.net>,
        Keith Busch <keith.busch@intel.com>,
        Sagi Grimberg <sagi@grimberg.me>, kvm@vger.kernel.org,
        "David S . Miller" <davem@davemloft.net>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Liang Cunming <cunming.liang@intel.com>,
        Wolfram Sang <wsa@the-dreams.de>, linux-kernel@vger.kernel.org,
        Kirti Wankhede <kwankhede@nvidia.com>,
        Jens Axboe <axboe@fb.com>,
        Alex Williamson <alex.williamson@redhat.com>,
        John Ferlan <jferlan@redhat.com>,
        Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Liu Changpeng <changpeng.liu@intel.com>,
        "Paul E . McKenney " <paulmck@linux.ibm.com>,
        Amnon Ilan <ailan@redhat.com>, Christoph Hellwig <hch@lst.de>,
        Nicolas Ferre <nicolas.ferre@microchip.com>,
        Jens Axboe <axboe@kernel.dk>
Subject: Re: [PATCH v2 06/10] nvme/core: add mdev interfaces
Message-ID: <20190503122902.GA5081@infradead.org>
References: <20190502114801.23116-1-mlevitsk@redhat.com>
 <20190502114801.23116-7-mlevitsk@redhat.com>
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On Thu, May 02, 2019 at 02:47:57PM +0300, Maxim Levitsky wrote:
> If the mdev device driver also sets the
> NVME_F_MDEV_DMA_SUPPORTED, the mdev core will
> dma map all the guest memory into the nvme device,
> so that nvme device driver can use dma addresses as passed
> from the mdev core driver

We really need a proper block layer interface for that so that
uring or the nvme target can use pre-mapping as well.