From: Srivatsa Vaddagiri <vatsa@codeaurora.org>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: tsoni@codeaurora.org, virtio-dev@lists.oasis-open.org,
will@kernel.org, konrad.wilk@oracle.com, jan.kiszka@siemens.com,
jasowang@redhat.com, christoffer.dall@arm.com,
pratikp@codeaurora.org,
virtualization@lists.linux-foundation.org,
iommu@lists.linux-foundation.org, stefano.stabellini@xilinx.com,
alex.bennee@linaro.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 5/5] virtio: Add bounce DMA ops
Date: Wed, 29 Apr 2020 15:39:53 +0530 [thread overview]
Message-ID: <20200429100953.GE5097@quicinc.com> (raw)
In-Reply-To: <20200429055125-mutt-send-email-mst@kernel.org>
* Michael S. Tsirkin <mst@redhat.com> [2020-04-29 05:52:05]:
> > > So it seems that with modern Linux, all one needs
> > > to do on x86 is mark the device as untrusted.
> > > It's already possible to do this with ACPI and with OF - would that be
> > > sufficient for achieving what this patchset is trying to do?
> >
> > In my case, its not sufficient to just mark virtio device untrusted and thus
> > activate the use of swiotlb. All of the secondary VM memory, including those
> > allocate by swiotlb driver, is private to it.
>
> So why not make the bounce buffer memory shared then?
Its a limitation by our hypervisor. When a secondary VM is created, two
memory segments are allocated - one private and other shared. There is no
provision for the secondary VM to make part of its private memory shared after
it boots. I can perhaps consider a change in swiotlb driver to accept the second
shared memory segment as its main working area (rather than allocate its own).
That would still not work I think where swiotlb is used for pass-thr devices
(when private memory is fine) as well as virtio devices (when shared memory is
required).
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2020-04-29 10:10 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-28 11:39 [PATCH 0/5] virtio on Type-1 hypervisor Srivatsa Vaddagiri
2020-04-28 11:39 ` [PATCH 1/5] swiotlb: Introduce concept of swiotlb_pool Srivatsa Vaddagiri
2020-04-29 0:31 ` kbuild test robot
2020-04-28 11:39 ` [PATCH 2/5] swiotlb: Allow for non-linear mapping between paddr and vaddr Srivatsa Vaddagiri
2020-04-28 11:39 ` [PATCH 3/5] swiotlb: Add alloc and free APIs Srivatsa Vaddagiri
2020-04-30 4:18 ` kbuild test robot
2020-04-28 11:39 ` [PATCH 4/5] swiotlb: Add API to register new pool Srivatsa Vaddagiri
2020-04-28 11:39 ` [PATCH 5/5] virtio: Add bounce DMA ops Srivatsa Vaddagiri
2020-04-28 16:17 ` Michael S. Tsirkin
2020-04-28 17:49 ` Srivatsa Vaddagiri
2020-04-28 20:41 ` Michael S. Tsirkin
2020-04-28 23:04 ` Stefano Stabellini
2020-04-29 4:09 ` Srivatsa Vaddagiri
2020-04-29 2:22 ` Lu Baolu
2020-04-29 4:57 ` Michael S. Tsirkin
2020-04-29 5:42 ` Lu Baolu
2020-04-29 6:50 ` Michael S. Tsirkin
2020-04-29 7:01 ` Lu Baolu
2020-04-29 9:44 ` Srivatsa Vaddagiri
2020-04-29 9:52 ` Michael S. Tsirkin
2020-04-29 10:09 ` Srivatsa Vaddagiri [this message]
2020-04-29 10:20 ` Michael S. Tsirkin
2020-04-29 10:26 ` Jan Kiszka
2020-04-29 10:45 ` Michael S. Tsirkin
2020-04-29 10:55 ` [virtio-dev] " Jan Kiszka
2020-04-29 10:34 ` Srivatsa Vaddagiri
2020-04-30 15:20 ` Konrad Rzeszutek Wilk
2020-04-29 3:35 ` Srivatsa Vaddagiri
2020-04-28 21:35 ` kbuild test robot
2020-04-28 22:18 ` kbuild test robot
2020-04-28 22:53 ` Stefano Stabellini
2020-04-29 21:06 ` kbuild test robot
2020-04-29 21:06 ` [RFC PATCH] virtio: virtio_pool can be static kbuild test robot
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=20200429100953.GE5097@quicinc.com \
--to=vatsa@codeaurora.org \
--cc=alex.bennee@linaro.org \
--cc=christoffer.dall@arm.com \
--cc=iommu@lists.linux-foundation.org \
--cc=jan.kiszka@siemens.com \
--cc=jasowang@redhat.com \
--cc=konrad.wilk@oracle.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mst@redhat.com \
--cc=pratikp@codeaurora.org \
--cc=stefano.stabellini@xilinx.com \
--cc=tsoni@codeaurora.org \
--cc=virtio-dev@lists.oasis-open.org \
--cc=virtualization@lists.linux-foundation.org \
--cc=will@kernel.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).