From: Christoph Hellwig <hch@lst.de>
To: Ram Pai <linuxram@us.ibm.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Jason Wang <jasowang@redhat.com>,
Alexey Kardashevskiy <aik@linux.ibm.com>,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org,
Paul Mackerras <paulus@ozlabs.org>,
iommu@lists.linux-foundation.org,
linuxppc-devel@lists.ozlabs.org, Christoph Hellwig <hch@lst.de>,
David Gibson <david@gibson.dropbear.id.au>
Subject: Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted
Date: Mon, 12 Aug 2019 14:13:24 +0200 [thread overview]
Message-ID: <20190812121324.GA9405@lst.de> (raw)
In-Reply-To: <20190811064621.GB5964@ram.ibm.com>
On Sat, Aug 10, 2019 at 11:46:21PM -0700, Ram Pai wrote:
> If the hypervisor (hardware for hw virtio devices) does not mandate a
> DMA API, why is it illegal for the driver to request, special handling
> of its i/o buffers? Why are we associating this special handling to
> always mean, some DMA address translation? Can't there be
> any other kind of special handling needs, that has nothing to do with
> DMA address translation?
I don't think it is illegal per se. It is however completely broken
if we do that decision on a system weide scale rather than properly
requesting it through a per-device flag in the normal virtio framework.
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next prev parent reply other threads:[~2019-08-12 12:13 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-29 17:08 [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted Thiago Jung Bauermann
2019-01-29 17:42 ` Thiago Jung Bauermann
2019-01-29 19:02 ` Michael S. Tsirkin
2019-01-30 2:24 ` Jason Wang
2019-01-30 2:36 ` Michael S. Tsirkin
2019-01-30 3:05 ` Jason Wang
2019-01-30 3:26 ` Michael S. Tsirkin
2019-01-30 7:44 ` Christoph Hellwig
2019-02-04 18:15 ` Thiago Jung Bauermann
2019-02-04 21:38 ` Michael S. Tsirkin
2019-02-05 7:24 ` Christoph Hellwig
[not found] ` <20190205072407.GA4311-jcswGhMUV9g@public.gmane.org>
2019-02-05 16:13 ` Michael S. Tsirkin
2019-03-26 16:53 ` Michael S. Tsirkin
2019-02-04 18:14 ` Thiago Jung Bauermann
2019-02-04 20:23 ` Michael S. Tsirkin
2019-03-20 16:13 ` Thiago Jung Bauermann
2019-03-20 21:17 ` Michael S. Tsirkin
2019-03-22 0:05 ` Thiago Jung Bauermann
2019-03-23 21:01 ` Michael S. Tsirkin
2019-03-25 0:57 ` David Gibson
2019-04-17 21:42 ` Thiago Jung Bauermann
2019-04-17 21:42 ` Thiago Jung Bauermann
[not found] ` <20190323165456-mutt-send-email-mst-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2019-04-17 21:42 ` Thiago Jung Bauermann
2019-04-17 21:42 ` Thiago Jung Bauermann
2019-04-19 23:09 ` Michael S. Tsirkin
2019-04-19 23:09 ` Michael S. Tsirkin
2019-04-25 1:01 ` Thiago Jung Bauermann
2019-04-25 1:01 ` Thiago Jung Bauermann
[not found] ` <875zr228zf.fsf-wxVGo8vDogbJvNEK5ZsId7p2dZbC/Bob@public.gmane.org>
2019-04-25 1:18 ` Michael S. Tsirkin
2019-04-25 1:18 ` Michael S. Tsirkin
2019-04-26 23:56 ` Thiago Jung Bauermann
2019-04-26 23:56 ` Thiago Jung Bauermann
2019-05-20 13:08 ` Michael S. Tsirkin
2019-05-20 13:16 ` Michael S. Tsirkin
2019-06-04 1:13 ` Thiago Jung Bauermann
2019-06-04 1:42 ` Michael S. Tsirkin
2019-06-28 1:58 ` Thiago Jung Bauermann
2019-07-01 14:17 ` Michael S. Tsirkin
2019-07-14 5:51 ` Thiago Jung Bauermann
2019-07-15 14:35 ` Michael S. Tsirkin
2019-07-15 20:29 ` Thiago Jung Bauermann
2019-07-15 20:36 ` Michael S. Tsirkin
2019-07-15 22:03 ` Thiago Jung Bauermann
2019-07-15 22:16 ` Michael S. Tsirkin
2019-07-15 23:05 ` Thiago Jung Bauermann
2019-07-15 23:24 ` Benjamin Herrenschmidt
2019-07-18 3:39 ` Thiago Jung Bauermann
2019-08-10 18:57 ` Michael S. Tsirkin
2019-08-10 22:07 ` Ram Pai
2019-08-11 5:56 ` Christoph Hellwig
2019-08-11 6:46 ` Ram Pai
2019-08-11 8:44 ` Michael S. Tsirkin
2019-08-12 12:13 ` Christoph Hellwig [this message]
2019-08-12 20:29 ` Ram Pai
2019-08-11 8:42 ` Michael S. Tsirkin
2019-08-11 8:55 ` Michael S. Tsirkin
2019-08-12 12:15 ` Christoph Hellwig
2019-09-06 5:07 ` Michael S. Tsirkin
2019-08-12 9:51 ` David Gibson
2019-08-13 13:26 ` Christoph Hellwig
2019-08-13 14:24 ` David Gibson
2019-08-13 15:45 ` Ram Pai
2019-08-26 17:48 ` Ram Pai
2019-08-11 8:12 ` Michael S. Tsirkin
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