KVM Archive on lore.kernel.org
 help / color / Atom feed
From: Michael Mueller <mimu@linux.ibm.com>
To: Halil Pasic <pasic@linux.ibm.com>,
	kvm@vger.kernel.org, linux-s390@vger.kernel.org,
	Cornelia Huck <cohuck@redhat.com>,
	Sebastian Ott <sebott@linux.ibm.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: virtualization@lists.linux-foundation.org,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Christoph Hellwig <hch@infradead.org>,
	Thomas Huth <thuth@redhat.com>,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	Viktor Mihajlovski <mihajlov@linux.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Janosch Frank <frankja@linux.ibm.com>,
	Claudio Imbrenda <imbrenda@linux.ibm.com>,
	Farhan Ali <alifm@linux.ibm.com>,
	Eric Farman <farman@linux.ibm.com>,
	"Jason J. Herne" <jjherne@linux.ibm.com>
Subject: Re: [PATCH v5 0/8] s390: virtio: support protected virtualization
Date: Thu, 13 Jun 2019 11:11:13 +0200
Message-ID: <4d10d4f8-aeb0-a5bc-6900-ab7901c01cf2@linux.ibm.com> (raw)
In-Reply-To: <20190612111236.99538-1-pasic@linux.ibm.com>

Halil,

I just ran my toleration tests successfully on current HW for
this series.

Michael

On 12.06.19 13:12, Halil Pasic wrote:
> Enhanced virtualization protection technology may require the use of
> bounce buffers for I/O. While support for this was built into the virtio
> core, virtio-ccw wasn't changed accordingly.
> 
> Some background on technology (not part of this series) and the
> terminology used.
> 
> * Protected Virtualization (PV):
> 
> Protected Virtualization guarantees, that non-shared memory of a  guest
> that operates in PV mode private to that guest. I.e. any attempts by the
> hypervisor or other guests to access it will result in an exception. If
> supported by the environment (machine, KVM, guest VM) a guest can decide
> to change into PV mode by doing the appropriate ultravisor calls.
> 
> * Ultravisor:
> 
> A hardware/firmware entity that manages PV guests, and polices access to
> their memory. A PV guest prospect needs to interact with the ultravisor,
> to enter PV mode, and potentially to share pages (for I/O which should
> be encrypted by the guest). A guest interacts with the ultravisor via so
> called ultravisor calls. A hypervisor needs to interact with the
> ultravisor to facilitate interpretation, emulation and swapping. A
> hypervisor  interacts with the ultravisor via ultravisor calls and via
> the SIE state description. Generally the ultravisor sanitizes hypervisor
> inputs so that the guest can not be corrupted (except for denial of
> service.
> 
> 
> What needs to be done
> =====================
> 
> Thus what needs to be done to bring virtio-ccw up to speed with respect
> to protected virtualization is:
> * use some 'new' common virtio stuff
> * make sure that virtio-ccw specific stuff uses shared memory when
>    talking to the hypervisor (except control/communication blocks like ORB,
>    these are handled by the ultravisor)
> * make sure the DMA API does what is necessary to talk through shared
>    memory if we are a protected virtualization guest.
> * make sure the common IO layer plays along as well (airqs, sense).
> 
> 
> Important notes
> ================
> 
> * This patch set is based on Martins features branch
>   (git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git branch
>   'features').
> 
> * Documentation is still very sketchy. I'm committed to improving this,
>    but I'm currently hampered by some dependencies currently.
> 
> * The existing naming in the common infrastructure (kernel internal
>    interfaces) is pretty much based on the AMD SEV terminology. Thus the
>    names aren't always perfect. There might be merit to changing these
>    names to more abstract ones. I did not put much thought into that at
>    the current stage.
> 
> * Testing: Please use iommu_platform=on for any virtio devices you are
>    going to test this code with (so virtio actually uses the DMA API).
> 
> @Sebastian: I kept your r-b on patch 2 "s390/cio: introduce DMA pools to
> cio" despite the small changes pointed out below. Please do complain if
> it ain't OK for you!
> 
> Change log
> ==========
> 
> v4 --> v5:
> * work around dma_pool API not tolerating NULL dma pool (patch 4)
> * make the genpool based dma pools API  tolerate NULL genpool (patch 2)
> * fix typo (patch 2)
> * fix unintended code move (patch 7)
> * add more r-b's
> 
> 
> 
> v3 --> v4
> * fixed cleanup in css_bus_init() (Connie)
> * made cio.h include genalloc.h instead of a forward declaration
>    (Connie)
> * added comments about dma_mask/coherent_dma_mask values (Connie)
> * fixed error handling in virtio_ccw_init() (Connie)
> * got rid of the *vc_dma* wrappers (Connie)
> * added some Reviewed-bys
> * rebased on top of current master, no changes were necessary
> 
> v2 --> v3:
> * patch 2/8
>      potential cio_dma_pool_init() returning NULL issue fixed
>      potential cio_gp_dma_create() returning NULL issue fixed
>      warning issues with doc type comments fixed
>      unused define statement removed
> * patch 3/8
>      potential cio_gp_dma_create() returning NULL issue fixed
>      whitespace issue fixed
>      warning issues with doc type comments fixed
> * patch 8/8
>      potential cio_dma_zalloc() returning NULL issue fixed
> 
> v1 --> v2:
> * patch "virtio/s390: use vring_create_virtqueue" went already upstream
> * patch "virtio/s390: DMA support for virtio-ccw" went already upstream
> * patch "virtio/s390: enable packed ring" went already upstream
> * Made dev.dma_mask point to dev.coherent_dma_mask for css, subchannel
>    and ccw devices.
> * While rebasing 's390/airq: use DMA memory for adapter interrupts' the
>    newly introduced kmem_cache  was replaced with an equivalent dma_pool;
>    the kalloc() allocations are now replaced with cio_dma_zalloc()
>    allocations to avoid wasting almost a full page.
> * Made virtio-ccw use the new AIRQ_IV_CACHELINE flag.
> * fixed all remaining checkpatch issues
> 
> RFC --> v1:
> * Fixed bugs found by Connie (may_reduce and handling reduced,  warning,
>    split move -- thanks Connie!).
> * Fixed console bug found by Sebastian (thanks Sebastian!).
> * Removed the completely useless duplicate of dma-mapping.h spotted by
>    Christoph (thanks Christoph!).
> * Don't use the global DMA pool for subchannel and ccw device
>    owned memory as requested by Sebastian. Consequences:
> 	* Both subchannel and ccw devices have their dma masks
> 	now (both specifying 31 bit addressable)
> 	* We require at least 2 DMA pages per ccw device now, most of
> 	this memory is wasted though.
> 	* DMA memory allocated by virtio is also 31 bit addressable now
>          as virtio uses the parent (which is the ccw device).
> * Enabled packed ring.
> * Rebased onto Martins feature branch; using the actual uv (ultravisor)
>    interface instead of TODO comments.
> * Added some explanations to the cover letter (Connie, David).
> * Squashed a couple of patches together and fixed some text stuff.
> 
> Halil Pasic (8):
>    s390/mm: force swiotlb for protected virtualization
>    s390/cio: introduce DMA pools to cio
>    s390/cio: add basic protected virtualization support
>    s390/airq: use DMA memory for adapter interrupts
>    virtio/s390: use cacheline aligned airq bit vectors
>    virtio/s390: add indirection to indicators access
>    virtio/s390: use DMA memory for ccw I/O and classic notifiers
>    virtio/s390: make airq summary indicators DMA
> 
>   arch/s390/Kconfig                   |   5 +
>   arch/s390/include/asm/airq.h        |   2 +
>   arch/s390/include/asm/ccwdev.h      |   4 +
>   arch/s390/include/asm/cio.h         |  11 ++
>   arch/s390/include/asm/mem_encrypt.h |  18 ++
>   arch/s390/mm/init.c                 |  47 ++++++
>   drivers/s390/cio/airq.c             |  37 +++--
>   drivers/s390/cio/ccwreq.c           |   9 +-
>   drivers/s390/cio/cio.h              |   2 +
>   drivers/s390/cio/css.c              | 134 ++++++++++++++-
>   drivers/s390/cio/device.c           |  68 ++++++--
>   drivers/s390/cio/device_fsm.c       |  49 +++---
>   drivers/s390/cio/device_id.c        |  20 ++-
>   drivers/s390/cio/device_ops.c       |  21 ++-
>   drivers/s390/cio/device_pgid.c      |  22 +--
>   drivers/s390/cio/device_status.c    |  24 +--
>   drivers/s390/cio/io_sch.h           |  20 ++-
>   drivers/s390/virtio/virtio_ccw.c    | 246 +++++++++++++++-------------
>   18 files changed, 538 insertions(+), 201 deletions(-)
>   create mode 100644 arch/s390/include/asm/mem_encrypt.h
> 

-- 
Mit freundlichen Grüßen / Kind regards
Michael Müller

IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Matthias Hartmann
Geschäftsführung: Dirk Wittkopp
Sitz der Gesellschaft: Böblingen
Registergericht: Amtsgericht Stuttgart, HRB 243294


  parent reply index

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-12 11:12 Halil Pasic
2019-06-12 11:12 ` [PATCH v5 1/8] s390/mm: force swiotlb for " Halil Pasic
2019-06-13  8:09   ` Michael Mueller
2019-07-11 21:48   ` Thiago Jung Bauermann
2019-06-12 11:12 ` [PATCH v5 2/8] s390/cio: introduce DMA pools to cio Halil Pasic
2019-06-12 14:23   ` Cornelia Huck
2019-06-13  8:13   ` Michael Mueller
2019-06-12 11:12 ` [PATCH v5 3/8] s390/cio: add basic protected virtualization support Halil Pasic
2019-06-13  8:21   ` Michael Mueller
2019-06-12 11:12 ` [PATCH v5 4/8] s390/airq: use DMA memory for adapter interrupts Halil Pasic
2019-06-12 14:35   ` Cornelia Huck
2019-06-12 15:11     ` Halil Pasic
2019-06-13  8:25   ` Michael Mueller
2019-06-12 11:12 ` [PATCH v5 5/8] virtio/s390: use cacheline aligned airq bit vectors Halil Pasic
2019-06-13  8:27   ` Michael Mueller
2019-06-12 11:12 ` [PATCH v5 6/8] virtio/s390: add indirection to indicators access Halil Pasic
2019-06-13  8:29   ` Michael Mueller
2019-06-12 11:12 ` [PATCH v5 7/8] virtio/s390: use DMA memory for ccw I/O and classic notifiers Halil Pasic
2019-06-13  8:32   ` Michael Mueller
2019-06-12 11:12 ` [PATCH v5 8/8] virtio/s390: make airq summary indicators DMA Halil Pasic
2019-06-13  8:35   ` Michael Mueller
2019-06-13  9:11 ` Michael Mueller [this message]
2019-06-13 11:14   ` [PATCH v5 0/8] s390: virtio: support protected virtualization Halil Pasic
2019-06-13 11:17     ` Michael Mueller

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4d10d4f8-aeb0-a5bc-6900-ab7901c01cf2@linux.ibm.com \
    --to=mimu@linux.ibm.com \
    --cc=alifm@linux.ibm.com \
    --cc=borntraeger@de.ibm.com \
    --cc=cohuck@redhat.com \
    --cc=farman@linux.ibm.com \
    --cc=frankja@linux.ibm.com \
    --cc=gor@linux.ibm.com \
    --cc=hch@infradead.org \
    --cc=heiko.carstens@de.ibm.com \
    --cc=imbrenda@linux.ibm.com \
    --cc=jjherne@linux.ibm.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=mihajlov@linux.ibm.com \
    --cc=mst@redhat.com \
    --cc=pasic@linux.ibm.com \
    --cc=sebott@linux.ibm.com \
    --cc=thuth@redhat.com \
    --cc=virtualization@lists.linux-foundation.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

KVM Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/kvm/0 kvm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 kvm kvm/ https://lore.kernel.org/kvm \
		kvm@vger.kernel.org kvm@archiver.kernel.org
	public-inbox-index kvm


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.kvm


AGPL code for this site: git clone https://public-inbox.org/ public-inbox