From: Niklas Schnelle <schnelle@linux.ibm.com>
To: Alex Williamson <alex.williamson@redhat.com>,
Cornelia Huck <cohuck@redhat.com>
Cc: "Jason Gunthorpe" <jgg@ziepe.ca>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-s390@vger.kernel.org,
"Matthew Rosato" <mjrosato@linux.ibm.com>,
"Pierre Morel" <pmorel@linux.ibm.com>,
"Christian Bornträger" <borntraeger@linux.ibm.com>
Subject: [PATCH v2 0/1] vfio/type1: Fix vfio-pci pass-through of ISM devices
Date: Wed, 4 Jan 2023 16:42:01 +0100 [thread overview]
Message-ID: <20230104154202.1152198-1-schnelle@linux.ibm.com> (raw)
Hi Alex,
This is v2 of my attempt of fixing an issue we have on s390 with vfio-pci
pass-through of the s390 specific virtual PCI device called ISM and used for
cross LPAR communication. As the patch tries to explain the fact that
vfio_test_domain_fgsp() uses an IOMMU mapping at IOVA 0 irrespective of any
reserved regions causes the ISM device to go into an error state and thus
becomes unusable for a KVM guest breaking pass-through. I tried to improve
the background and explanation compared to v1 hope its more clear now.
As for testing, I tested this based on current master on both on s390 where it
skips the reserved 0x0-0x100000000 range and on an AMD Ryzen 3990X where it
continues to do the test on DMA address 0 and sets domain->fgsp to true.
Thanks,
Niklas Schnelle
Changes since v1:
- Reworded commit message to hopefully explain things a bit better and
highlight that usually just mapping but not issuing DMAs for IOVAs in
a resverved region is harmless but still breaks things with ISM devices.
- Added a check for PAGE_SIZE * 2 alignment (Jason)
Niklas Schnelle (1):
vfio/type1: Respect IOMMU reserved regions in vfio_test_domain_fgsp()
drivers/vfio/vfio_iommu_type1.c | 30 +++++++++++++++++++-----------
1 file changed, 19 insertions(+), 11 deletions(-)
--
2.34.1
next reply other threads:[~2023-01-04 15:42 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-04 15:42 Niklas Schnelle [this message]
2023-01-04 15:42 ` [PATCH v2 1/1] vfio/type1: Respect IOMMU reserved regions in vfio_test_domain_fgsp() Niklas Schnelle
2023-01-05 16:06 ` Matthew Rosato
2023-01-06 17:24 ` Alex Williamson
2023-01-06 18:03 ` Jason Gunthorpe
2023-01-09 8:49 ` Niklas Schnelle
2023-01-09 9:00 ` Niklas Schnelle
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=20230104154202.1152198-1-schnelle@linux.ibm.com \
--to=schnelle@linux.ibm.com \
--cc=alex.williamson@redhat.com \
--cc=borntraeger@linux.ibm.com \
--cc=cohuck@redhat.com \
--cc=jgg@ziepe.ca \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-s390@vger.kernel.org \
--cc=mjrosato@linux.ibm.com \
--cc=pmorel@linux.ibm.com \
/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).