iommu.lists.linux-foundation.org archive mirror
 help / color / mirror / Atom feed
From: Christoph Hellwig <hch@lst.de>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: linux-s390@vger.kernel.org, Janosch Frank <frankja@linux.ibm.com>,
	"Lendacky, Thomas" <Thomas.Lendacky@amd.com>,
	Jason Wang <jasowang@redhat.com>,
	Cornelia Huck <cohuck@redhat.com>, Ram Pai <linuxram@us.ibm.com>,
	linux-kernel@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	Halil Pasic <pasic@linux.ibm.com>,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	iommu@lists.linux-foundation.org,
	David Gibson <david@gibson.dropbear.id.au>,
	Michael Mueller <mimu@linux.ibm.com>,
	Viktor Mihajlovski <mihajlov@linux.ibm.com>,
	Robin Murphy <robin.murphy@arm.com>,
	Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH 0/2] virtio: decouple protected guest RAM form VIRTIO_F_IOMMU_PLATFORM
Date: Fri, 21 Feb 2020 17:41:51 +0100	[thread overview]
Message-ID: <20200221164151.GD10054@lst.de> (raw)
In-Reply-To: <20200220163055-mutt-send-email-mst@kernel.org>

On Thu, Feb 20, 2020 at 04:33:35PM -0500, Michael S. Tsirkin wrote:
> So it sounds like a host issue: the emulation of s390 unnecessarily complicated.
> Working around it by the guest looks wrong ...

Yes.  If your host (and I don't care if you split hypervisor, ultravisor
and megavisor out in your implementation) wants to support a VM
architecture where the host can't access all guest memory you need to
ensure the DMA API is used.  Extra points for simply always setting the
flag and thus future proofing the scheme.
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

  parent reply	other threads:[~2020-02-21 16:41 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-20 16:06 [PATCH 0/2] virtio: decouple protected guest RAM form VIRTIO_F_IOMMU_PLATFORM Halil Pasic
2020-02-20 16:06 ` [PATCH 1/2] mm: move force_dma_unencrypted() to mem_encrypt.h Halil Pasic
2020-02-20 16:11   ` Christoph Hellwig
2020-02-20 16:23     ` Christian Borntraeger
2020-02-20 16:31       ` Christoph Hellwig
2020-02-20 17:00         ` Christian Borntraeger
2020-02-21  3:27         ` David Gibson
2020-02-21 13:06           ` Halil Pasic
2020-02-21 15:48             ` Michael S. Tsirkin
2020-02-21 18:07               ` Halil Pasic
2020-02-24  3:33                 ` David Gibson
2020-02-24 18:49                   ` Halil Pasic
2020-02-25 18:08                     ` Cornelia Huck
2020-02-28  0:23                       ` David Gibson
2020-02-20 16:06 ` [PATCH 2/2] virtio: let virtio use DMA API when guest RAM is protected Halil Pasic
2020-02-20 16:13   ` Christoph Hellwig
2020-02-21  2:59     ` David Gibson
2020-02-21  3:41       ` Jason Wang
2020-02-21 13:31         ` Halil Pasic
2020-02-21 13:27       ` Halil Pasic
2020-02-21 16:36       ` Christoph Hellwig
2020-02-24  6:50         ` David Gibson
2020-02-24 18:59         ` Halil Pasic
2020-02-21 14:33     ` Halil Pasic
2020-02-21 16:39       ` Christoph Hellwig
2020-02-21 18:16         ` Halil Pasic
2020-02-22 19:07       ` Michael S. Tsirkin
2020-02-24 17:16         ` Christoph Hellwig
2020-10-28 14:24           ` Alexander Graf via iommu
2020-10-28 18:01             ` Michael S. Tsirkin
2020-02-20 20:55   ` Michael S. Tsirkin
2020-02-21  1:17     ` Ram Pai
2020-02-21  3:29       ` David Gibson
2020-02-21 13:12     ` Halil Pasic
2020-02-21 15:39       ` Tom Lendacky
2020-02-24  6:40         ` David Gibson
2020-02-21 15:56       ` Michael S. Tsirkin
2020-02-21 16:35         ` Christoph Hellwig
2020-02-21 18:03         ` Halil Pasic
2020-02-20 20:48 ` [PATCH 0/2] virtio: decouple protected guest RAM form VIRTIO_F_IOMMU_PLATFORM Michael S. Tsirkin
2020-02-20 21:29 ` Michael S. Tsirkin
2020-02-21 13:37   ` Halil Pasic
2020-02-20 21:33 ` Michael S. Tsirkin
2020-02-21 13:49   ` Halil Pasic
2020-02-21 16:41   ` Christoph Hellwig [this message]
2020-02-24  5:44     ` David Gibson
2020-02-21  6:22 ` Jason Wang
2020-02-21 14:56   ` Halil Pasic
2020-02-24  3:38     ` David Gibson
2020-02-24  4:01     ` Jason Wang
2020-02-24  6:06       ` Michael S. Tsirkin
2020-02-24  6:45         ` Jason Wang
2020-02-24  7:48           ` Michael S. Tsirkin
2020-02-24  9:26             ` Jason Wang
2020-02-24 13:40               ` Michael S. Tsirkin
2020-02-25  3:38                 ` Jason Wang
2020-02-24 13:56               ` Halil Pasic
2020-02-25  3:30                 ` Jason Wang

Reply instructions:

You may reply publicly 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=20200221164151.GD10054@lst.de \
    --to=hch@lst.de \
    --cc=Thomas.Lendacky@amd.com \
    --cc=borntraeger@de.ibm.com \
    --cc=cohuck@redhat.com \
    --cc=david@gibson.dropbear.id.au \
    --cc=frankja@linux.ibm.com \
    --cc=iommu@lists.linux-foundation.org \
    --cc=jasowang@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=linuxram@us.ibm.com \
    --cc=mihajlov@linux.ibm.com \
    --cc=mimu@linux.ibm.com \
    --cc=mst@redhat.com \
    --cc=pasic@linux.ibm.com \
    --cc=robin.murphy@arm.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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).