From: Alex Williamson <alex.williamson@redhat.com>
To: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Bart Van Assche <bvanassche@acm.org>,
linux-nvme@lists.infradead.org, Fam Zheng <fam@euphon.net>,
Jens Axboe <axboe@fb.com>, Sagi Grimberg <sagi@grimberg.me>,
kvm@vger.kernel.org, Wolfram Sang <wsa@the-dreams.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Liang Cunming <cunming.liang@intel.com>,
Nicolas Ferre <nicolas.ferre@microchip.com>,
linux-kernel@vger.kernel.org,
Liu Changpeng <changpeng.liu@intel.com>,
Keith Busch <keith.busch@intel.com>,
Kirti Wankhede <kwankhede@nvidia.com>,
Christoph Hellwig <hch@lst.de>,
Paolo Bonzini <pbonzini@redhat.com>,
Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
John Ferlan <jferlan@redhat.com>,
"Paul E . McKenney" <paulmck@linux.ibm.com>,
Amnon Ilan <ailan@redhat.com>,
"David S . Miller" <davem@davemloft.net>
Subject: Re: [PATCH 0/9] RFC: NVME VFIO mediated device
Date: Wed, 20 Mar 2019 11:03:25 -0600 [thread overview]
Message-ID: <20190320110325.465c1dff@x1.home> (raw)
In-Reply-To: <8994f43d26ebf6040b9d5d5e3866ee81abcf1a1c.camel@redhat.com>
On Wed, 20 Mar 2019 18:42:02 +0200
Maxim Levitsky <mlevitsk@redhat.com> wrote:
> On Wed, 2019-03-20 at 08:28 -0700, Bart Van Assche wrote:
> > On Tue, 2019-03-19 at 16:41 +0200, Maxim Levitsky wrote:
> > > * All guest memory is mapped into the physical nvme device
> > > but not 1:1 as vfio-pci would do this.
> > > This allows very efficient DMA.
> > > To support this, patch 2 adds ability for a mdev device to listen on
> > > guest's memory map events.
> > > Any such memory is immediately pinned and then DMA mapped.
> > > (Support for fabric drivers where this is not possible exits too,
> > > in which case the fabric driver will do its own DMA mapping)
> >
> > Does this mean that all guest memory is pinned all the time? If so, are you
> > sure that's acceptable?
> I think so. The VFIO pci passthrough also pins all the guest memory.
> SPDK also does this (pins and dma maps) all the guest memory.
>
> I agree that this is not an ideal solution but this is a fastest and simplest
> solution possible.
FWIW, the pinned memory request up through the vfio iommu driver count
against the user's locked memory limits, if that's the concern. Thanks,
Alex
next prev parent reply other threads:[~2019-03-20 17:03 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190319144116.400-1-mlevitsk@redhat.com>
2019-03-19 14:41 ` [PATCH 1/9] vfio/mdev: add .request callback Maxim Levitsky
2019-03-19 14:41 ` [PATCH 2/9] nvme/core: add some more values from the spec Maxim Levitsky
2019-03-19 14:41 ` [PATCH 3/9] nvme/core: add NVME_CTRL_SUSPENDED controller state Maxim Levitsky
2019-03-19 14:41 ` [PATCH 4/9] nvme/pci: use the NVME_CTRL_SUSPENDED state Maxim Levitsky
2019-03-20 2:54 ` Fam Zheng
2019-03-19 14:41 ` [PATCH 5/9] nvme/pci: add known admin effects to augument admin effects log page Maxim Levitsky
2019-03-19 14:41 ` [PATCH 6/9] nvme/pci: init shadow doorbell after each reset Maxim Levitsky
2019-03-19 14:41 ` [PATCH 7/9] nvme/core: add mdev interfaces Maxim Levitsky
2019-03-20 11:46 ` Stefan Hajnoczi
2019-03-20 12:50 ` Maxim Levitsky
2019-03-19 14:41 ` [PATCH 8/9] nvme/core: add nvme-mdev core driver Maxim Levitsky
2019-03-19 14:41 ` [PATCH 9/9] nvme/pci: implement the mdev external queue allocation interface Maxim Levitsky
2019-03-19 14:58 ` [PATCH 0/9] RFC: NVME VFIO mediated device Maxim Levitsky
2019-03-25 18:52 ` [PATCH 0/9] RFC: NVME VFIO mediated device [BENCHMARKS] Maxim Levitsky
2019-03-26 9:38 ` Stefan Hajnoczi
2019-03-26 9:50 ` Maxim Levitsky
2019-03-19 15:22 ` your mail Keith Busch
2019-03-19 23:49 ` Chaitanya Kulkarni
2019-03-20 16:44 ` Maxim Levitsky
2019-03-20 16:30 ` Maxim Levitsky
2019-03-20 17:03 ` Keith Busch
2019-03-20 17:33 ` Maxim Levitsky
2019-04-08 10:04 ` Maxim Levitsky
2019-03-20 11:03 ` Felipe Franciosi
2019-03-20 19:08 ` Re: Maxim Levitsky
2019-03-21 16:12 ` Re: Stefan Hajnoczi
2019-03-21 16:21 ` Re: Keith Busch
2019-03-21 16:41 ` Re: Felipe Franciosi
2019-03-21 17:04 ` Re: Maxim Levitsky
2019-03-22 7:54 ` Re: Felipe Franciosi
2019-03-22 10:32 ` Re: Maxim Levitsky
2019-03-22 15:30 ` Re: Keith Busch
2019-03-25 15:44 ` Re: Felipe Franciosi
2019-03-20 15:08 ` [PATCH 0/9] RFC: NVME VFIO mediated device Bart Van Assche
2019-03-20 16:48 ` Maxim Levitsky
2019-03-20 15:28 ` Bart Van Assche
2019-03-20 16:42 ` Maxim Levitsky
2019-03-20 17:03 ` Alex Williamson [this message]
2019-03-21 16:13 ` your mail Stefan Hajnoczi
2019-03-21 17:07 ` Maxim Levitsky
2019-03-25 16:46 ` Stefan Hajnoczi
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