From: Matthew Rosato <mjrosato@linux.ibm.com>
To: alex.williamson@redhat.com, cohuck@redhat.com, schnelle@linux.ibm.com
Cc: pmorel@linux.ibm.com, borntraeger@de.ibm.com, hca@linux.ibm.com,
gor@linux.ibm.com, gerald.schaefer@linux.ibm.com,
linux-s390@vger.kernel.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/4] vfio-pci/zdev: Fixing s390 vfio-pci ISM support
Date: Tue, 19 Jan 2021 15:50:35 -0500 [thread overview]
Message-ID: <8b655baa-cda0-a78f-4504-649e9580c87a@linux.ibm.com> (raw)
In-Reply-To: <1611086550-32765-1-git-send-email-mjrosato@linux.ibm.com>
On 1/19/21 3:02 PM, Matthew Rosato wrote:
> Today, ISM devices are completely disallowed for vfio-pci passthrough as
> QEMU will reject the device due to an (inappropriate) MSI-X check.
> However, in an effort to enable ISM device passthrough, I realized that the
> manner in which ISM performs block write operations is highly incompatible
> with the way that QEMU s390 PCI instruction interception and
> vfio_pci_bar_rw break up I/O operations into 8B and 4B operations -- ISM
> devices have particular requirements in regards to the alignment, size and
> order of writes performed. Furthermore, they require that legacy/non-MIO
> s390 PCI instructions are used, which is also not guaranteed when the I/O
> is passed through the typical userspace channels.
>
> As a result, this patchset proposes a new VFIO region to allow a guest to
> pass certain PCI instruction intercepts directly to the s390 host kernel
> PCI layer for execution, pinning the guest buffer in memory briefly in
> order to execute the requested PCI instruction.
>
> Changes from RFC -> v1:
> - No functional changes, just minor commentary changes -- Re-posting along
> with updated QEMU set.
>
Link to latest QEMU patch set:
https://lists.gnu.org/archive/html/qemu-devel/2021-01/msg04881.html
> Matthew Rosato (4):
> s390/pci: track alignment/length strictness for zpci_dev
> vfio-pci/zdev: Pass the relaxed alignment flag
> s390/pci: Get hardware-reported max store block length
> vfio-pci/zdev: Introduce the zPCI I/O vfio region
>
> arch/s390/include/asm/pci.h | 4 +-
> arch/s390/include/asm/pci_clp.h | 7 +-
> arch/s390/pci/pci_clp.c | 2 +
> drivers/vfio/pci/vfio_pci.c | 8 ++
> drivers/vfio/pci/vfio_pci_private.h | 6 ++
> drivers/vfio/pci/vfio_pci_zdev.c | 160 ++++++++++++++++++++++++++++++++++++
> include/uapi/linux/vfio.h | 4 +
> include/uapi/linux/vfio_zdev.h | 34 ++++++++
> 8 files changed, 222 insertions(+), 3 deletions(-)
>
next prev parent reply other threads:[~2021-01-19 20:52 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-19 20:02 [PATCH 0/4] vfio-pci/zdev: Fixing s390 vfio-pci ISM support Matthew Rosato
2021-01-19 20:02 ` [PATCH 1/4] s390/pci: track alignment/length strictness for zpci_dev Matthew Rosato
2021-01-19 20:02 ` [PATCH 2/4] vfio-pci/zdev: Pass the relaxed alignment flag Matthew Rosato
2021-01-19 20:02 ` [PATCH 3/4] s390/pci: Get hardware-reported max store block length Matthew Rosato
2021-01-19 20:02 ` [PATCH 4/4] vfio-pci/zdev: Introduce the zPCI I/O vfio region Matthew Rosato
2021-01-20 13:21 ` Niklas Schnelle
2021-01-20 17:10 ` Matthew Rosato
2021-01-20 17:28 ` Niklas Schnelle
2021-01-20 17:40 ` Matthew Rosato
2021-01-21 20:50 ` Alex Williamson
2021-01-21 10:01 ` Niklas Schnelle
2021-01-21 15:57 ` Matthew Rosato
2021-01-22 23:48 ` Alex Williamson
2021-01-25 14:40 ` Matthew Rosato
2021-01-25 15:42 ` Cornelia Huck
2021-01-25 15:52 ` Matthew Rosato
2021-01-26 23:18 ` Alex Williamson
2021-01-27 14:23 ` Matthew Rosato
2021-01-27 15:53 ` Alex Williamson
2021-01-27 17:45 ` Cornelia Huck
2021-01-27 18:27 ` Matthew Rosato
2021-01-19 20:50 ` Matthew Rosato [this message]
2021-01-20 9:02 ` [PATCH 0/4] vfio-pci/zdev: Fixing s390 vfio-pci ISM support Pierre Morel
2021-01-20 14:02 ` Matthew Rosato
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